Video: Mullet vs 29er With the Same Geometry - Which is Faster?

Jun 14, 2021 at 9:12
by Seb Stott  

When the UCI scrapped the rule banning mixed wheel sizes for racing, a lot of teams rushed to experiment with mixed wheel size bikes, which have now become known as mullets. In the early days, a mullet usually meant either squeezing a 29" front wheel and fork into a 27.5" bike, or a 29er bike with a 27.5" rear wheel.

A couple of years ago, Mike Kazimer tested out a 29er bike with 27.5” and 29” rear wheels. The results were … inconclusive - neither setup was outright faster.

But with these setups, you're compromising the geometry to accommodate the mixed wheel sizes. If you fit a smaller rear wheel to a 29er, the bottom bracket might be a little bit too low; if you fit a 29er front wheel to a 27.5” bike, the BB is probably going to be too high. And either way, the head and seat angles might be slacker than what you want, or at least slacker than the bike was designed for.

Now, though, when people talk about a mullet bike, they usually mean a bike that's purpose built for mixed wheel sizes, and these are everywhere now. They allow you to have the mixed wheel sizes without any compromise in geometry.

16.04.21. Pinkbike Forest of Dean Rider Seb Stott. PIC Andy Lloyd www.andylloyd.photography
16.04.21. Pinkbike Forest of Dean Rider Seb Stott. PIC Andy Lloyd www.andylloyd.photography

There's an increasing number of bikes which are designed to fit either wheel sizes in the rear, such as this Geometron G1. By using interchangeable flip-chips, it can accommodate either wheel size in the back without changing the BB height or frame angles. Because the flip chips are between the link and the rear axle, instead of between the link and the shock, the leverage ratio and the suspension kinematics are pretty similar with both wheel sizes too.

16.04.21. Pinkbike Forest of Dean Rider Seb Stott. PIC Andy Lloyd www.andylloyd.photography
By swapping out the black chips (Geometron calls these Seatstay Mutators) behind the rocker, the G1's geometry can be maintained with either wheel size. Pictured are the longer chips for a 27.5" wheel.

I've tested this bike against the clock with both the 29er and the mullet set up on a couple of different tracks. The first track has a series of fast corners with not much gradient, which is a little awkward to carry speed through, then it drops into a fast section with a load of big roots at the bottom before it drops onto a fire road.

I know this track well, but I did a handful of scoping runs to get fully up to speed before getting the stopwatch out. Then I did two runs on the 29er, then four runs on the mullet, then swapped back and did two more runs on 29". This was to further minimize the effect of getting faster as I became more familiar with the track.

16.04.21. Pinkbike Forest of Dean Rider Seb Stott. PIC Andy Lloyd www.andylloyd.photography


Results

My average time was very slightly faster on the 29er, at 49.5s vs 49.9s on the mullet setup. That's just under half a second or 1% difference. It's not statistically significant, so we can't say the 29er was "the winner" here because there just isn't enough data to go on.

Track 1 lap times
Lap 1 49.9 (29")
Lap 2 49.5 (29")
Lap 3 50.5 (27.5")
Lap 4 50.1 (27.5")
Lap 5 49.9 (27.5")
Lap 6 49.1 (27.5")
Lap 7 49.3 (29")
Lap 8 49.1 (29")
Average: 49.45 (29"), 49.9 (27.5")

Subjectively, what surprised me most is how similar the bikes felt in the turns.

When swapping from the 29 to the 27.5” rear wheel, I did feel that the bike tipped into the corner a little bit more willingly. I'm not going to say quicker, but it seems to take less effort to lean into the turn. I don't think this is necessarily “better”; it's just different. And I only noticed this on the first couple of turns so I think that if there is a difference, you get used to it pretty quickly. The 29er is a bit like having a car with slightly heavier steering. It doesn't mean you can’t go round corners just as quickly, it just takes a bit more effort to initiate the turn. But really, the main takeaway is that the difference is very, very subtle. In fact, if it was a blind test I’m not 100% sure if I could tell the difference. But either way, it didn't feel like the mullet was faster through the turns, and that's certainly what the stopwatch suggested.

However, I did notice a difference at the bottom of the track where there's a section of big chunky roots followed by a flat straight. Here, the 29er didn't hang up quite as much and felt a little smoother through the rough. This might have allowed the 29er to edge ahead on the following straight.

Unless you're on the brakes, about 60% of your weight is on the rear wheel, and the rear is more likely to fall into the worst holes and bumps than the front wheel too (this is why we run higher tire pressures at the back). So, the size of the rear wheel probably makes more difference to carrying speed than the front, although the size of the front wheel makes more difference to bike's tendency to "trip up" on large bumps.

For my second test track, I looked for somewhere the benefits of the mullet were most likely to shine. I picked a short section with a steeper gradient to it, which is essentially a series of tight, alternating corners. This is where I thought a mullet was most likely to come into its own. And because the track is so short, I could do lots of runs in quick succession and get very familiar with the track, which is important for noticing differences in handling. But to be honest, both setups felt pretty much indistinguishable. I don't think in a blind test I would have been able to tell the difference and the times back this up.

Track 2 lap times
Lap 1 19.38 (29")
Lap 2 18.70 (29")
Lap 3 19.40 (29")
Lap 4 19.15 (27.5")
Lap 5 18.28 (27.5")
Lap 6 19.29 (27.5")
Lap 7 18.61 (27.5")
Lap 8 (crashed) (27.5")
Lap 9 18.36 (27.5")
Lap 10 18.39 (29")
Lap 11 18.46 (29")
Lap12 18.31 (29")
Average: 18.77 (29"), 18.74 (27.5")

I attempted six runs on each wheel size, though on one run with the mullet setup I had a small crash so I discounted that time. The average time was almost identical with both wheel sizes. The difference in the average was much smaller than the range of times posted on either wheel setup, so there’s essentially no difference.

16.04.21. Pinkbike Forest of Dean Rider Seb Stott. PIC Andy Lloyd www.andylloyd.photography

Conclusion

To sum up, in this test I found no real benefit to the mullet setup over the 29er, whether subjectively or against the clock. The main difference I can feel is that the 29er is slightly smoother through very rough terrain. It's not a huge difference, but it's the biggest one I noticed when descending.

But that's not to say that they don’t have a place. I'm 190 centimetres tall (six foot three) so I never really buzz my ass on the rear tire, but for some people this is a problem. Very short riders may still benefit from a full 27.5" setup so that they can get the bar height low enough. But if you're in that in-between size where you can get the bar height in the right place with a 29er front end, but you want the extra clearance on the rear, then a mullet makes a lot of sense.

A brand manager told me that in their internal testing riders over six foot tall (183cm) didn't feel much benefit with a mullet, but many riders under that height did. So perhaps there are benefits for smaller riders, but if you're tall like me you may as well enjoy the roll-over benefits of a 29er.

From manufacturer's perspective, smaller wheels are easier for designers to package into the back of a bike while preserving tire clearance, seat tube shape, chain-line, stiffness and other considerations. Plus, a mullet configuration can work well with a broad range of riders, even if those at the extremes of the height spectrum might be better off with a full 29er or 27.5" bike. Smaller wheels are tougher too, which compensates for the additional punishment a rear wheel receives. After all, this was a major reason behind the OG mullets with 24"/26" wheels like the Specialized Big Hit.

16.04.21. Pinkbike Forest of Dean Rider Seb Stott. PIC Andy Lloyd www.andylloyd.photography
Tire clearance isn't really an issue if you're tall.

When it comes to the claims of better cornering agility compared to a 29er, I think there was a very subtle difference on the faster turns on the first track, but otherwise both bikes felt almost identical to me, and whatever differences exist are easy to adapt to and not necessarily bad. I know that some people swear there is a benefit here, but with the riding style that I have I can't feel it, nor can I tell a difference with a stopwatch. And that’s despite going out of my way to find terrain likely to benefit the smaller back wheel.

It’s worth saying that I've done similar tests on both of these tracks before, comparing different fork offsets, tire sizes, suspension settings etc..., and I noticed bigger differences with many of these tests. I would say the difference between available fork offsets is quite subtle, but even that made more of a difference to handling than the size of the rear wheel.

What about climbing? Well, there I really did notice a big difference. In theory, the 29er rear wheel helps when getting up and over bumps on technical climbs, but the main difference I noticed is that the smaller back wheel makes the gearing easier. That’s by far the most tangible difference I felt throughout this test.


366 Comments

  • 627 11
 Is not about what's faster, it's about what you pick and want to be a dick about.
  • 20 3
 100%, this ^^^
; )
  • 38 3
 You said dick pic
  • 100 0
 Smile Mullet is replacing full 27,5" bikes (Bronson, Patrol). Maybe they should have compared mullet to a full 27,5" bike?
  • 12 1
 @dennis72: That would actually be cool!
  • 2 0
 Well said brother!
  • 6 2
 @dennis72: in non data driven terms.
Vs 29, slightly slower in a strait line, rocks and chatter. As fun as a 27.5, less chance of tire buzz.
Vs 27.5 not quite as snappy, less likely to shit your pants when hauling into rocks, slabs and harsh transitions.
Vs both sizes, much harder to wash the front wheel in a turn and much easier to drift.
  • 11 49
flag willhill12345 (Jun 22, 2021 at 11:36) (Below Threshold)
 Geomotron bikes are rubbish!!!!!!!!!!
  • 31 11
 Bla bla bla... this test is lame. That man is so tall; beside a 29er he looks like me beside a 26".
Ask Minnaar or Pierron who both keep a full 29er because they are tall Versus Brosnan of Danny Hart who prefer a mullet to save their asses...
  • 5 4
 @willhill12345: LOL!! Wow. Triggered.
  • 8 1
 @catweasel: I usually ride my BMX with 20" wheels at the local gravel pumptrack. This morning I brought my hardtail mountainbike with 26" wheels front and back. Seattube is 400mm, seat is slammed so room above the bike wasn't an issue. Still, I was nowhere as quick as I am on the BMX. Actually, Fabien Barel already mentioned a good while ago. Smaller wheels interact more with the ground. Which implies that rough ground won't hold you back as much, yet at the same time it becomes harder to extract speed from the ground. I like the beauty of the latter so I'm more than happy with my 26" wheeled mountainbike for mountainbiking and the 20" wheeled BMX at the pumptrack. But yeah as you mention, if your terrain has a lot of big loose rubble (like just below the snow line) then indeed there is not really a way to make sense of it and extract speed from the terrain, could just as well make it a little easier on yourself and ride bigger wheels and more suspension travel.
  • 5 0
 @dennis72: I had the same thought as you. It would be nice to compare Mullet bikes vs full 27,5 wheels bikes
  • 29 1
 I’m pretty sure being faster is more about ball size rather than wheel size.
  • 30 1
 Armchair Pinkbike Commenter Engineer here; Unfortunatly we can't take any of these results seriously, runs could have been completely different.
1. Did flatulence help more on any of the runs increasing propulsion
2. Was there more salt on your neighbors pizza last week
3. Porcupine hardware sonic equinox

I'm afraid there are just too many variables.
  • 6 1
 @danstonQ: Pierron is running Mullet
  • 1 4
 @xMARTINx: He is also not tall.
  • 8 1
 I love that Seb is doing this testing. Buuuut I’m not sure that an 18 second run in the Forest of Dean is enough evidence either way.

The FoD is pretty damn flat. It’s like 100 vertical metres. It’s good fun. But it’s a long way from a WC track, where mullets are currently fast(er?).

Back to back timed runs on some Alpine courses please Seb, I’m sure Brian has the budget with all these mullets out next year!
  • 3 2
 Whichever one I’m on is fastest.
  • 2 0
 @danstonQ: I'm 6'2 and still buzz the rear here and there. Def more so than when I had a mxr.
  • 1 0
 I ruined the 420 vote. Sorry.
  • 4 4
 So this so called, test is more effective than the testing Pro teams are doing?
If mullet bikes are winning world cups , your silly test is useless.
  • 2 0
 The product manager for the trek 96’er is pissed right now
  • 3 0
 @vinay: another big factor in why your 26 was slower in your pump track example is the loss of energy through the suspension fork.
  • 1 0
 So is camcoz the pinkbike AI bot, or is the story's author Seb Stott the AI bot?

So hard to get these AI quiz questions right.
  • 3 0
 @L0rdTom: He's 5 11, he's not exactly short.
  • 2 0
 @dwbaillar: Yeah, could be. My fork (Magura TS8 at 120mm travel) actually has a lock-out (DLO) but it can only be locked with a remote and as I never cared for lock-out I never installed it. That said, I don't think I even pump that much through the arms, more through the legs. But to me it feels like with the bigger wheels, the bowls just feel less "curved". It is hard to describe with just text, but maybe you can imagine what I'm aiming at. I feel I need this curve to push against. That said, I surely make it round the track on the mtb and also pump loads on the trail. I have also never ridden an mtb with 27.5" or 29" wheels and of course the difference between 26" and 27.5" or even 29" wouldn't be as dramatic as between 20" and 26".
  • 1 0
 @dwbaillar: Yeah, could be. My fork (Magura TS8 at 120mm travel) actually has a lock-out (DLO) but it can only be locked with a remote and as I never cared for lock-out I never installed it. That said, I don't think I even pump that much through the arms, more through the legs. But to me it feels like with the bigger wheels, the bowls just feel less "curved". It is hard to describe with just text, but maybe you can imagine what I'm aiming at. I feel I need this curve to push against. That said, I surely make it round the track on the mtb and also pump loads on the trail. I have also never ridden an mtb with 27.5" or 29" wheels and of course the difference between 26" and 27.5" or even 29" wouldn't be as dramatic as between 20" and 26".
  • 2 0
 @danstonQ: So you're saying the test is lame and then repeat Seb's conclusions to prove it?
  • 2 6
flag willhill12345 (Jun 23, 2021 at 0:17) (Below Threshold)
 @Blaenavonbutt: geomotron are way too slack and also they are rubbish up hills
  • 1 2
 @iridedj: yeah he's pretty average height. Further up it was said he was sticking with his 29er because he was tall, and neither fact were correct. Therefore mullets for the masses!
  • 1 1
 @endurocat: kind of a stupid comment really.
The test for the Pro teams has nothing to do with the performance of Seb and his setup, riding style, what tracks he rides.
Riders on complete bikes win world cups, not a specific wheel size combination. But their WC runs has nothing to do with Seb's test. The rider is different Wink

You might be surprised what WC teams don't test once you are away from some of the top riders!
  • 1 3
 @vinay: I don´t know how much BMX bikes change in the last 20 years,but MTB bikes are night and day. My cousin has my old 26 inch enduro bike from 2012 and ridding it from time to time it is a total shock. New bikes are much much faster and easy to ride,much more natural experience about the handling of the bike. In my old 26 inch bike you need to be crazy precise with your lines and the room for error is minimal compared to my 29 inch enduro.
Most of my local trails are not good to any hardtail,even XC people rides full suspension bikes and walk away sketchy parts hahaha.
Around Madrid, trails are so gnarly and dirty you need a tank/bike to ride at good pace. Then you go to any bike park and it looks like a highway to me.
  • 12 0
 @Altron5000: As i said elsewhere, shorter runs make it easier to feel the difference because there's less time between each run and you can do more runs to see if one setup is consistently better. With a few runs of a long track it's easy to confuse a good run with a good setup. Also, if it was faster over a long descent it would likely be faster (on average) over lots of small descents. Whether the Mullet would perform better on steeper descents, I'm not sure, but it's possible.

The problem with WC results is there's no control - we don't know if Bruni or Reece or whoever would be just as fast or faster on a full 29er. I'm not saying there isn't a benefit for riders who are shorter than me (which is most people), but for me there doesn't seem to be much benefit. And if we're going to reference the WC to support our arguements, Minnaar is still on 29" Wink

Having said that, I'd happily accept an all-expenses-paid trip to the Alps to test mullets some more @brianpark
  • 3 0
 @homerjm: Yeah, agreed mountainbikes can be different and so can BMX bikes. I think I bought my BMX back in 2004 (Stolen Goblin, Stolen is the BMX brand from Anthony Revell, Revell bikes is his MTB brand). It is probably heavy by modern standards. 14mm axles and 48 spokes front and rear, ACS freewheel. But I use it pretty much exclusively on the pumptrack and I feel weight isn't much of an issue there. Only because it is loose gravel, it can be scary. I just ordered a pair of Maxxis DHF tires (20x2.4") which should help with lateral grip. But I'm actually quite happy with the hardtail as it is. Geometry can be found here: www.btr-fabrications.com/products/ranger-frame/#frame-options. I've got the 26" wheeled model, size large. Only modification I had made is that I went with a 400mm seattube and had the top tube lowered accordingly. The frame was finished early May 2018, so it is not even that old.
  • 2 0
 @seb-stott: Seb are you looking to do more testing on this as a long term project? It would be interesting to read about your results after 6 / 12 months of testing and riding.

As I understand it CP has done a lot of testing of mullet vs 29. It would be good to see his data as I'm sure he has a ton. Maybe another podcast with him specifically about it - your previous podcast was awesome.

BPW could be a good spot for testing.
  • 1 1
 @fartymarty: The best thing about testing is the results and the validity of the results.
Seb's test is only really valid for Seb and how Seb is feeling/riding just now and how the track conditions suit the different setups and his riding style.
2 months time the results could be different.
GoPro footage analysis can be interesting too when testing as it can show where 1 setup is better than the other or where mistakes cost you time.
  • 1 0
 @fartymarty: link to previous podcast with Chris Porter?
  • 2 0
 @L0rdTom: AJs recent podcast on NSMB was good as well.
  • 2 1
 @betsie: I completely agree - and there are so many other factors involved that have a much bigger influence which is noted in the article.

I just like Seb's scientific approach and would be interested in see how it plays out long term. My gut feel is that there won't be a significant difference for him or anyone over 6' and has the strength to muscle around a full 29.

Another interesting comparison would be a heavy wide 275 wheel / tyre combo vs a light 29 wheel / tyre combo.
  • 1 0
 @vinay: for a hardtail it looks really good,it is true that a modern 26 inch geo would ride much better than older bikes. That is something I would like to try,a 26 inch bike with very modern geo,long wheelbase and new suspension layout.
29 inch are quite good today, at 178 cm I ride a L size Spes.Enduro,quite large bike but very fun to ride in gnarly trails and is still good to any mellow ride too. It is the first bike I can throw around corners without thinking or as aggressive as I want.
But I would never buy an enduro hardtail to ride in my local trails.
  • 1 0
 @fartymarty: I have done lots and lots of this type of testing. I always find the results interesting and they only apply to me.
I have legacy runs on Gopro also that I have saved, splits down tracks and setups written down, conditions, mistakes etc too.
The wheel size argument as well as the geometry, handlebar width etc has always been polarising and how much of it is marketing and how much of it is down to data that is relevant to the average person is questionable. Placebo effect can be a factor too, or lets call it preconceptions.

I will be racing small wheels this weekend (old school 26), with what people would call narrow rims these days. All based on data for me.
  • 1 0
 LOL! I say pick ALL the sizes and be a dick about ALL of them....

Hard to believe he can't feel a carving difference between the two set ups thought...??

Though it's funny how you can "feel" faster with a given set up, check the time and find out your feelings are all wrong...
  • 1 0
 @stiingya: how cool would it be to have all the sizes.
Unless you are racing, do many really care.
Sounds like this kind of article is not for you.
This is all about what works for Seb and how he tested, probably more relevant to a different kind of rider to you. Some folk love geeking things out.
  • 2 0
 @homerjm: Yeah, that's it, isn't it? Ride the bike that allows you to ride the trails you ride the way you want. I can imagine in the rough rubble you have there you can appreciate a bike that helps every bit. But I live in The Netherlands. The fun I'm having is the small jumps and drops, cornering and the beauty of extracting speed from the terrain (that is, pumping). Too much suspension and big wheels would steal that from me, so that defies the point. Of course my lack of suspension travel or limited gearing (11-36 cassette) make things harder for me than they could possibly be but that's fine. If I wouldn't want these challenges, I'd ride on the road. And of course if I'd regularly ride your terrain, I'd probably more than appreciate a proper enduro bike too. But as it is now, I'm super happy riding my bike the way it is now.
  • 1 1
 @betsie: it's all marketing (or wanketering as Hambini correctly calls it). It's an easy metric (along with weight) to play on. Things like tyre pressure are going to have a bigger impact on how your bike rides than what size rear wheel you have.
  • 1 0
 First time in the 600+ club. Thank you everyone for your support
  • 1 0
 @willhill12345: mines really comfortable up hill, so much grip on real steep stuff too. And has no issues at all with switch backs.
Don't find it too slack either, great for the steep rough stuff.
  • 1 3
 @fartymarty: I certainly don't disagree with that.
What has marketing had people buy...

How many moved from 26 to 27.5 to 29 and now to mullet.
From 750mm funn full on bars to flat bars!
From 760 bars to 800 or 810 and now we are told we need high rise bars. Bars with flex built into them too
What about from 23mm rims to wide rims (remember when we laughed at wide rims).
From tubes to tubeless to different sealants to half tubes to inserts...
From 11 to 36T in the UK to 10 to 52T and a 32T up front! What you climbing in the UK that needs that!
From a chain device and a bash guard to no chain device and narrow wide to a top guide and now some going back to a bash guard.
Some pro riders riding angle sets these days to steepen the head angle.
Grips that mould themselves to the shape of your hands!
Grips that have different shapes and patterns along their length.
Saddles with cut outs along them and strange shapes to help you sit better, then folk put them on their Dh bikes.
Every different tyre type, 3C compound, different side walls, yet one of the fastest dry tyres is still the old minion DHF ST which hasnt changed in decades.

The list goes on and on.
But marketing have made a fortune for companies because people love new, shiny things that make the 1 second faster on their 20 minute Strava lap for an nice large investment.
  • 2 1
 @betsie: That's why I prefer to stay clear from the latest and greatest. Out of everything I've seen recently, I might try the new Galfer green brake pad compound someday... for my fifteen year old brakes.
  • 1 1
 @betsie: You hit the nail firmly (and quite humoursly) on the head. I'd be lying if I said I wasn't guilty of falling for a few of the marketing ploys noted above.
  • 2 0
 @vinay: This is the beauty of having a sweet custom HT (like your BTR). Once its built and set up well there isn't much need to change anything.
  • 1 1
 @betsie: good points
  • 1 0
 @fartymarty: Yeah, it probably is kind of how one defines his or her wishes. Are you just looking for superlatives (lighter, more efficient, more "progressive" etc) then you can buy the bleeding edge stuff now but when someone makes something better, you'll want that. For me I kind of made up my mind where I wanted my bars, how low the top tube, the colour, where to have my weight positioned between the wheels etc so when you can get that and it works out then there is no point getting something else. Another factor is that I like the idea that the tool I have for having so much fun is made by people who absolutely loved creating it. It may not be a factor for everyone but it is important to me. So yeah, I can't see myself ever part with it Smile .
  • 2 1
 @vinay: It's also the realisation that the are always compromises to be made no matter what bike you are riding and by riding a HT you are making and accepting bigger compromises - this then allows you to get on with the business of having fun.

Back to the topic of 29 vs Mullet - as so correctly pointed out by the OP - pick one and be a dick about it. Accept and embrace compromise. Ride the wrong bike and have fun doing it.
  • 1 0
 @fartymarty: Yeah, but also: the first thing I look for in a bike is that it doesn't get in the way of what I'm trying to do. Hence the low top tube I'm always looking for, the proper amount of reach be able to move for and aft... Geometry is always king, suspension doesn't change anything about that. But yeah, I just live in a place where it is not like I should need a lot of help from my bike to ride these trails. The way the bike is now, it leaves just enough challenges for me to cope with. So it could be looked at as a compromise. I always view it as the trail (and the way/speed you're riding it) throw challenges at you. Some you're able to deal with, some of the stuff makes it too much and you want to leave up to your bike to deal with. More suspension, big wheels, pedal assist... For me it is enough to leave some small rubble up to my fork and tires to deal with and I'm happy to take on everything else. And of course, it is not like I NEED to ride it. I'm no racer, I'm no traveler either. I ride these trails because I like the challenges they throw at me. And I've got the bike that leaves just enough for me to do. And more importantly, has the geometry that doesn't get in the way Smile .
  • 118 6
 I run mullet on my Forbidden Druid with the Ziggy link. It makes the bike more fun to ride for me. I dont care about lap times. I dont care about stats. It makes the bike easier to pop into manual, its easier to jump, and its more fun in the corners. Key here is more fun in the corners. Not faster in the corners. Also, i just think it looks cool.


Biking is supposed to be fun right?
  • 10 0
 Agree with all that!
  • 5 0
 Same bike same set up and I completely agree.
  • 4 0
 Best part is, it’s both more fun and faster for many.
  • 14 0
 Personally, I have zero interest in a mullet vs. my full 29er. But I couldn't agree more with your premise: pick your gear because it gets you stoked and increases your fun! Glad you're digging your ride.
  • 8 0
 Yep same here... I've run all the set-ups over the past couple years. I'm on a full 29 right now and will be going back to a mullet next season.

I've found that's he right, in terms of speed, they're pretty much the same, but I found the mullet to be more fun and more confidence inspiring, especially in really steep double black+ gnar.

As an average sized rider, there's no reason for me not to be on a mullet.
  • 10 0
 This seems to be the one thing people avoid talking about in the Mullet debate...is it more fun, flickable, slashy, whippy, whatever and does it jump better? Those are the things i care about...not the stop watch. The article kind of alludes to everything being the same tho...so maybe that's the reality?
  • 5 0
 @Svinyard: mine feels like a more confident 27.5 as opposed to a more flickable 29 if that makes sense
  • 2 22
flag willhill12345 (Jun 22, 2021 at 11:37) (Below Threshold)
 Geomotron bikes are rubbish!!!!!!!!!!
  • 15 1
 If people want more flickable bikes, why not go back to 275?
  • 3 0
 Your comment is more relevant to most riders than the stopwatch debate. Biking is more about fun and adventure for a lot of us, as racing is taking more of a backseat. And, if it makes the gearing for the climbs feel a bit better, well, that's another win for the mullet, MW, MX.
  • 6 0
 @willhill12345: I had a Geometron, it was pretty awesome! I’m guessing Geomotron is some cheap knockoff sold in big box stores for you to be calling it rubbish?
  • 5 0
 You should go out with a friend sometime and do a truly blind test. Have them setup the bike on different configurations and see if you can notice the difference. I think so much of this is all placebo effect. You buy a new upgrade, ziggy link, and your brain tells you it was totally worth it. I'm convinced the vast majority of riders would not be able to tell the difference, similar to what he found here. When it comes to saving a second or two at the world cup level, then I see the benefit. But I do totally agree, mtb is about having fun out in the forest. If this upgrade makes things more fun for you, then you're doing it right!
  • 3 5
 The point is there was no difference in how the bike performed. Hence it's a fad!
  • 5 0
 @jaydawg69: My 26" broke, I had minimal options and ended up with a 29: with a mullet option. 6 months of riding full 29 and while I enjoy rolling over everything, I was looking for more nimble, so I tried the 27.5 wheel, and it suits me. I'm 5'8" and the 29 just felt too big, even if it was very capable.
  • 3 0
 @DylanH93: It's not Mullets feel different. They are slower when it's not as steep though. 29er speed is real. But, mullets pop off of everything.
  • 12 2
 @oldmanjoe: Sounds like 27.5 all round would have done the job perfectly
  • 3 3
 @DylanH93: ok if you dont notice a smaller wheel on the rear with a slacker ha and a lower bb while riding you might consider changing sport.
  • 4 0
 my hightower just seems to be a lil more fun to ride as a mullet seems easier to manual too which is a plus for me
I think the mullets are winnin here bra dawgs
#mulletfolife
  • 1 0
 @jaydawg69: because...Kirt Voreis makes 29 bikes flickable..
  • 6 1
 @MattP76: The point is that it is as fast as full 29, feels better to ride, stronger and lighter rear wheel and gives you more clearance to the back wheel. Hence it is better and will be the main standard for DH and Enduro in the future. Recent race results and looking at the pro's bikes backs this up.
  • 1 0
 Exactly. Same with my Specialized Enduro. Totally agree. More fun by a large margin. I don’t care about speed at that point.
  • 3 0
 I know this might be shocking to some of you but fun and fast are _not_ mutually exclusive or inversely proportional. The same argument about people being fast on the uphills are slow on the downhills and vice versa. Some of us have more fun and are faster than you both ways.
  • 2 0
 @GBeard: this is so true. Since I started riding thousands of km more this past year and 30+ days at the bike park I’ve improved. Gotten faster uphill and down. And it is all much more fun the faster you go. Uphill and down. And I’m going faster because I’m in better shape uphill. And faster because I’m technically better downhill. (Therefore I can have more fun uphill by going faster without more fitness if I had an eBike, right?)
  • 4 4
 @JamesR2026: But it doesn't. We have ridden and raced hard same size wheels for decades and now, especially over last year, people think Mullets are the best invention ever. It's just rubbish. Most of this is brainwashing by the industry pushing you to buy a Mullet as they don't want to offer 27.5 anymore. This is a fad and it will disappear.
  • 2 3
 @kylar: honesty there are so bad, they pedal uphill terribly and the axle path is rubbish
  • 1 2
 I have to agree with all the 5ft9 guys. I'm riding a mullet and it gives me more room to move around the bike.
Seb is 9% bigger than me which means he should be riding a 31.5" front / 30" rear mullet. I'm not even joking. WC DH riders, even the smaller ones have settled on 29" as being quickest. Surely it makes sense when everyone is hard against this limit that we should try bigger!
  • 3 0
 @willhill12345: You're that AI, aren't you?
  • 2 1
 @rojo-1: mullet is winning everything in WC DH. Full 29 has almost disappeared
  • 1 1
 @JamesR2026: Mullets aren't winning. The riders are I bet the riders would still win on same size wheels. Mullets are a fad.
  • 1 0
 @kylar: nope I am real dude
  • 3 1
 @MattP76: I just mulleted my 2020 Enduro. Huge change. Way more fun! I don’t understand those who can’t appreciate the difference. Maybe they don’t ride enough? I know some beginners will ride for miles before they discover their tire or fork have 2psi in them.
  • 1 0
 @ybsurf: I thought the point was that head angle and bb don't change when you've got a specific link though.. Also in a blind test do you really think you'd be able to tell the difference between mullet or normal, assuming same geometry? Don't plan on changing sports anytime soon haha, although I do love weight training as well.
  • 4 2
 @MattP76: nah, full 29 DH bikes were a fad. It's over.
  • 3 3
 @JamesR2026: Mullets will be over when people realise reality that the make not difference whatsoever
  • 3 3
 @MattP76: manufacturers have to make more money so they have to invent something every couple of years.
  • 2 4
 @jaydawg69: Shame they don't invent something worthwhile instead of pushing fads on us
  • 2 2
 @jaydawg69: just watch as everyone goes mullet, then in a couple years some crazy manufacturer comes up with the insane idea of using the same wheels front and back. Instant upgrade time!
  • 1 0
 @DylanH93: A bike is basically 2 triangles and it took industry 30'ish years to figure out the angles and even then I don't think it's optimal.
  • 3 1
 @MattP76: mate, that's why 29er DH bikes are over. Like you said, it makes no difference to speed so why not go for the stronger/lighter/more clearance/better feeling option?
Have you actually tried it or are you just salty that you have bought a redundant bike?
  • 86 2
 you have the averages reversed - the 29" was 49.9 and the 27.5 was 49.5 (at least according to your numbers shown).
  • 34 15
 Mullet wins, I going home.
  • 4 2
 I thought it looked a little suspect to me too!
  • 5 3
 @robw515:

The mullet lost, because it caused a wreck.

Seriously though, the first chart is mislabeled. The outcomes still stand…
  • 11 4
 obvius media manipulation imo
  • 3 0
 @jwdenver I came here for the same comment.
  • 19 2
 @jwdenver, good catch, the numbers have been updated - the averages and outcomes still stand.
  • 6 1
 @mikekazimer: but in the video @seb-stott says that he did 2 mullet runs first, then 4 on the 29, then 2 more mullet runs.

So the results are wrong (his 27.5 runs were faster), or he misspoke in the video about the order of the runs.

I mean, I don’t think half a second is particularly meaningful anyways. But it’d be nice to get to the bottom of it
  • 12 1
 @sdurant12, the current numbers in both charts are the correct results.
  • 3 1
 @sdurant12: not the case ...29 destroyed...
  • 1 0
 @sdurant12: half a second over less than a minute is huge. Maybe not for normal people though.
  • 3 0
 Thanks for pointing this out. I got the order wrong in the write-up - I did 29" first for both tracks because it saved on a wheel swap. That's fixed now. The average times were correct from the off, so the 29er had the faster average time on the first track, but it's not statistically significant anyway.
  • 51 0
 Hey Seb, check your math on track 1. I’m pretty sure you got the averages mixed up between the 27.5 and 29.
  • 19 0
 Completely changes the tone and summary of this video.
  • 2 1
 @cgreaseman: oh man... if this is true you're absolutely right. I hope they clear this up..
  • 10 0
 Correct! His average values are correct (49.9 and 49.45, just are actually for 29 & 27.5, respectively).

You can also see a general trend of his times getting faster throughout the day, but there did look to be a slight regression when he went back to the full 29.
  • 6 3
 Classic pb
  • 2 2
 I think the chart is mislabeled. He rode 29, 27.5, then 29 again…
  • 5 0
 I don't fully get the conclusion tbh, if the times are essentially identical, and he thinks he couldn't tell the difference in a blind test, how did the 29"r win? Why wouldn't everyone pick the lighter, stronger, cheaper wheel size? It's better all round!
  • 1 0
 @audeo03: In the video he says he rode the 27.5 then 29 then 27.5 again...
  • 23 1
 @wilsondaj, the averages and outcomes were correct, it was the individual times that were mixed up. That's been corrected.
  • 2 1
 yeah, if you remove the 49.9 and 49.1 times that both wheel sizes got, you get two times in the 50s for 29 and two in the 49s for 27.5. Don't even have to do math.
  • 31 0
 Thanks Seb been looking forward to this one. That Geometron gives a great platform to play with the other variables you mention in isolation of whee size. What really does allow you to go quicker.

How hard were you trying on the runs? 90% 80% 100%?

After 15 years away from mtb at a high level and experiencing how other sports approach these kind of performance questions I think the gravity side of the sport has got stuck on a pretty ineffective way of testing. The norm seems to have become to ride at a speed the tester feels they aren’t going to make mistakes. I’ve seen 90% effort written a lot.
Trouble is if the speed isn’t enough that a tested variable is the limiting factor then all runs become a grey blur of sameness.
Here the main thing being tested is the riders sense of speed rather than a performance factor.

The factors that tend to make a significant difference with this mode of testing are those not directly under the control of the rider. Things like rolling resistance.
  • 4 0
 It's a tricky question and a good point you bring up. I try to ride as if it's a race run, so I'm trying to go as fast as I can every time. It's obviously important to pick a track where speed depends on control and grip rather than balls or fitness. I actually find this makes my times more consistent, and it's more relevant to racing. As you say, if you're going "80%", there's nothing to stop you going 81% the next time. I definitely think faster riders will get more consistent times when riding at the edge though.

The problem with going as fast as you can is crashing - I had one crash in this test. If you have too many crashes and discount those times you're potentially biasing the results in favor of a setup which may be harder to control. It's tricky and none of these real world tests are perfect.
  • 2 0
 @seb-stott: thanks, good reply and sounds like for timed runs you got the effort level just right.

Recently I’ve been “rearranging that equation” while trying to decide on frame size. Instead of measuring the variable against time I’ve been measuring it against mistakes and crashes. It takes some commitment to go at a set of corners with the intent of going fast enough to crash but it’s proved to be really insightful and lots of fun.

Rather than give a greyish outcome, things can get pretty clear cut when your beyond what you think your limit is. Would make for a rubbish written article but probably a good video.
  • 30 1
 If you have no problem riding a 29er I think a mullet setup is probably not for you as there is almost no benefit and quite a few downsides. I think smaller people, who aren't comfortable riding a 29er, but really want the easier rollover up front will like it and may find it worth their while.

I rode a mullet bike for about a year before the first Ripmo came out and I switched to full 29. It was good. Biggest difference I noticed on the full 29 was that the rear rolled over bumps noticeably better. Better for being a sled.

Beyond that, the differences are very subtle. Yeah the gearing thing is pretty obvious but easy to solve.

Biggest downside to mullet is how it works with spares etc. You cant move a front tire to the back for instance. Want to go on a trip and bring a spare tire? Now you have to bring 2... Want to carry a spare tube? I guess you carry both sizes. The 27.5 tube will work on the 29 but it's a pain. etc. etc.

It got surprisingly annoying and inconvenient surprisingly quickly. It's not that big of a deal, sure, but the benefit to mullet is also so, so minor as to be overshadowed by the downsides.
  • 14 3
 27.5 tubes fit in 29" tires.
  • 5 0
 I agree with this, it seems like the main concerns are practicality, rather than actual performance:

-A mullet is more practical if you are short and the 29er wheel buzzes you
-A full 29er is more practical gear-wise. You only need to keep one size of tire, rim strips, tubes, rims around.
  • 5 36
flag nvranka (Jun 22, 2021 at 10:38) (Below Threshold)
 Nope, mullet is superior for many regardless of being tall or short. Talk to some riders who can actually...you know...ride well.

And If you don’t have a spare wheel set built up for a trip what are you even doing bro
  • 3 12
flag ceecee (Jun 22, 2021 at 11:05) (Below Threshold)
 27" rear wheel benefits *:

Better acceleration; accommodates a smaller cassette
Lighter; uses a lighter tire--helps shock
Strength: weight
Mud/tire clearance

*also applies to front wheel--sub fork for shock--and 26"

@Old-Guy: and 29" in 27. Go rubber
  • 8 1
 For your average rider, a mullet setup is the new upgrade for those who've ran out of upgrades to buy lol.
  • 25 2
 My understanding was that it's highly dependent on your height...mullet helps shorter riders not buzz their butt on the rear tire on steep tracks (and probably other advantages also I admit....I ain't a pro). I suppose butt size might come into play as well......pls repeat the test with variety of heights and butt sizes.
  • 9 1
 Yeah, come on Seb, go get a fat suit and redo the tests! It'll make the photos more entertaining at the very least!
  • 4 0
 I would think it could also depend on suspension design. A rearward axle path would help with the issue of a smaller wheel getting hung up, no?
  • 2 1
 @ReformedRoadie: True. I wonder if the results would be very different if he tested using a hardtail. 175mm of rear travel can mask a lot.
  • 9 4
 On proper steep dh, tall guys similarly find 29 to be in the way.
  • 7 2
 Results per lap are also not cumulatively repetitive on such short timed sections.
When considering wheel size, fatigue, momentum & ability to handle variety of terrain over an extended distance are the factors this test did not do well.

Anyone who has raced DH for a long time can tell you that 3 minute tracks are really where you see time differentiations. You have to be going along taxing yourself and the bike facing all major obstacle types for the effects of a more beneficial setup to manifest. Something you do at 1 minute into a 3 minute run can multiply or even compound your speed on course and show up as a noticeable block of time at track's end.

Running such a short track is not going to expose real time gaps. Even rider input and fatigue compound over the course of a longer run, which what really separates race runs.
  • 2 4
 Also Yoann Barelli said this. Up to 180 mullet makes sense but not above.
  • 3 0
 I second butt sizes, we gotta get J-Lo and Kim Kardashian on one, and then compare to Hank Hill and Taylor swift on another. Only THEN we can determine if mullet is worth it.
  • 2 0
 @jomacba: J-Lo, FTW. End of story.
  • 1 1
 @squarewheel: Tell that to Brosnan
  • 4 8
flag nvranka (Jun 22, 2021 at 11:29) (Below Threshold)
 @blowmyfuse: you’re making the mistake of thinking anyone with capability / a brain is creating this content. It’s the blind leading the blind.
  • 1 0
 True that. I buzzed my butt today twice on my hardtail on Heavy Flow. And it’s a 27.5. And I’m short.
  • 3 0
 @nvranka: never found that ..But iam near 6'4 with legs longer than the rest of me.
  • 1 0
 @bohns1: The real question is, what's your buttsize?
  • 3 0
 @kcy4130: Sounds like I need to remove a few vertebrae as well.
  • 1 0
 @bohns1: I have the same long long leg issue, what bike are you riding, and is it comfy?
  • 1 0
 @jomacba: bubble
  • 2 0
 @T4THH: SB130 that I made into a lunch ride. Need that steep seat tube angle
  • 34 8
 #marketing
  • 2 1
 And also, 100%, this ^^^
; )
  • 9 1
 Yes and no. When WC DH racers are trying it as soon as the rules allow, even though their sponsor doesn’t sell one...that’s telling. If marketing was king at that level, you wouldn’t see so many sharpied out Maxxis or Magic Marys. All that matters is what’s fastest, even if it is rider preference or in a riders head.
  • 24 1
 This is a great video. Very informative. I don't think I'll bother trying a mullet after seeing this.
  • 14 0
 A 190cm man is in the 98th percentile of height of the population in the USA. This means 98% of men are shorter than this guy. Because we're keeping score the 2ed percentile of height in the USA is 158cm (5'2"). To try to draw any conclusion outside the tallest 2% of riders would be insane.
  • 5 1
 Took a little thinking to convert that to freedom units. But being 194cm tall I have no tire buzzing. But most of my riding friends are 6” or so shorter than I. 27.5 is their jam as it should be.
  • 4 0
 Excellent observation, it makes me really want to see this same test done with multiple riders between 5ft and 6ft. I've got a friend who is 6'2" and he seems to really like the 29ers, but myself at 5'7" can't get into it and much prefer 27.5 or older 26 bikes. Haven't spent any real time on a mullet but I might love it.
  • 3 0
 I tried to make this point in the article. Shorter riders may feel more of a benefit, but I can only speak for my height. But if the mullet has a cornering benefit to do with gyroscopic torque or camber thrust (as a few have claimed) I would have though tall riders would feel that too.
  • 2 0
 @seb-stott: maybe the wording should go more like “Because an overwhelming majority of people are much shorter than me, the most crucial variable will remain unaddressed.”
  • 4 0
 @robw515: I think the question we should all be asking is why as kids our wheel sizes increase with our bikes to fit your body as you grow, then suddenly stop when we hit 5’1”? There are a few companies building bikes with size specific wheels and I think more should pay attention.
  • 2 0
 @holmesslice: Exactly, I couldn't agree more. I've said many times: I used to watch my 6'4" friends struggle on weird awkward disproportionate 26" bikes, now I watch my 5'2" friends struggle on weird awkward 29" bikes. Why can't XS frames be 26ers and XXL frames be 29ers with proportional use of 26, 27.5, and 29 across the sizing.
  • 16 0
 No difference in time, and they felt almost identical too. Just the reassurance I needed to stick with with 650b.
  • 16 0
 Mull it over... I see what you did there!
  • 14 3
 Remember when the bike industry was pushing 2.8 tires to be the latest and greatest and introduced boost 148 to accommodate and all our bikes value tanked! 2.8. Not falling for this mullet stuff, last thing I need is a garage of mixed wheelsets to sell at pennies on the dollar.
  • 3 1
 It'll be interesting to see how things are in the next few years. Plus size was all the rage a few years ago haha.
  • 9 0
 I do feel wheel size has more to do with bike size. It's the same way for kids, as they grow they use bigger wheels. I saw a kid on a size M with 29 inch wheels and he had a tonne of trouble with the back wheel bumping him forward. I ride an XL 29 and have never had an issue. This is my very unscientific study result: XS and S 27.5, M Mullet, L and XL 29. There would be exemptions based on what you're using your bike for but it's more a general rule of thumb.
  • 8 0
 this. i'm 5'1 barely and ride a small frame. i don't think 29 is meant for everyone. i have owned 29, 27.5, two 26ers, now back on two 27.5 bikes but i really enjoyed 26. i think that if a bike company is putting out an XS or small size frame at least they should have the option of 27.5
  • 2 0
 @crysvb: I'm with you . I'm right on the edge of size small/medium frame threshold, many bikes have crappy standover hight, basically any bike where the shocks mounts to under the top tube. I built my custom Team GT distortion into a 26er or 26/650b. The medium distortion has 695mm standover which is very low. Most Bikes are built with SOH as an afterthought and some can't be low due to suspension design. My wife is your size and I found her a XS used xprezzo wu handmade in Quebec very low SoH fit her perfect tough to find a bike to fit her.
  • 2 0
 @crysvb: I think it's great when companies have both 27.5 and 29 options for their different models. I know nukeproof and vitus both do that. I've definitely seen a few others brands too.
  • 1 0
 @DylanH93: Yeah... We saw a bit of this when 27.5 bikes started coming out. Numerous companies offered bikes that could run 26 or 27.5. Canfield and Banshee come to mind.
  • 14 1
 #science
  • 10 15
flag mybaben (Jun 22, 2021 at 9:52) (Below Threshold)
 Fauci is that you? LOL. JK. Wink
  • 10 15
flag conoat (Jun 22, 2021 at 11:16) (Below Threshold)
 @mybaben: don't question him, otherwise you are anti-science!
  • 3 8
flag mybaben (Jun 22, 2021 at 12:05) (Below Threshold)
 @conoat: Right?! LOL.
  • 7 9
 @conoat: science is my religion. I pray to Fauci three times a day. If you dare question science then you've committed the ultimate sin.
  • 6 5
 @DylanH93: @conoat So funny that people down-voted me above...It was just a joke, and I thought a decent one. Wink Some people....
  • 5 7
 @mybaben: people are stupid. the same people that refuse to accept that Saint Fauci could be wrong, and possibly purposefully so, are the same people that think being white gives you an inherent advantage, but also that a trans weightlifter competing in the women's division isn't an advantage. they don't trust science, they trust CNN.
  • 5 4
 @conoat: you’re right. We should have injected bleach and stuck light bulbs up are asses to treat Covid.
  • 2 4
 @ReformedRoadie: look, I don't care what you stick in your bum....whatever does it for you, but I really don't know what your proclivities have to do with the question at hand?
  • 1 1
 @conoat: There are certainly many inconsistencies in people's beliefs and attitudes for sure! Very selective in their applications of science...
  • 1 1
 @ReformedRoadie: dude who the hell ever said that though? Far as I could tell trump merely talked about alternatives they were looking into and people interpreted that as "inject bleach and stick a light bulb up your ass"? Just, what??? How do you make that logical leap? I'm all for criticism of trump but stuff like that is where I draw the line. It's more ridiculous than he ever was.
  • 4 0
 @DylanH93: www.youtube.com/watch?v=zicGxU5MfwE
you're right. he said inject disinfectants, not bleach.
  • 1 1
 @ReformedRoadie: exactly, idk how people went from that to "inject bleach". And the whole light thing lol. UV-C is already used for disinfecting water supplies, biological labs, meat packaging plants, even fish tanks. That's nothing new. There were even studies showing sun light destroyed the virus, which isn't surprising lol. Yet it went from that to "stick a light bulb up your ass" just wtf lol. Wish more people would actually take the time to look up the original source for themselves, kudos for that.
  • 10 0
 I'd like to see a full 27.5 setup added to this test...if they even exist lol.
  • 4 0
 What is this, 2010? LOL
  • 1 0
 @nouseforaname: haha. I just bought a 2021 27.5 commencal supreme! However they are now officially extinct, I got one of the last ones on clearance.
  • 9 2
 Depends on the bike also. I mulleted a 29 enduro and it now is a beast. In its original set up it was not. Too high a bb and a bit too steep in the HA for most aggressive riding. Also allowed me to be behind the bike a bit more with the 27.5 rear. I flipped between wheel sizes a lot but the improvement with the 27.5 rear is massive. Maybe the key to mullet is out of the norm Geo. Look at the grim donut. Is whack but rides.
  • 4 1
 Came here to say the same thing. I have a 2017 Spesh Enduro 29 and going "ghetto" mullet transforms the bike for downhill performance. On my "test track" which has some steeps and some deep, fast berms I'm a good couple seconds faster on the mullet version.
I do notice that my (coil) suspension is a lot less supportive and progressive though. I'm going to try increasing the spring rate to see how it performs.
  • 3 18
flag nvranka (Jun 22, 2021 at 11:32) (Below Threshold)
 Thing is, content here is created by and for folks who don’t ride aggressive dh.
  • 7 0
 Much of the benefits you guys are talking about is a geometry change that results when going to the bigger front wheel. Same effect could be had with something like a Cane Creek adjustable head set or moving the stanchions up or down through the clamps if you have a dual crown.
  • 2 0
 @BDKR: You're likely right. Slacker HA and lower BB. My spesh always felt a bit tall and now it rips the bends. I do have another 29-er bike with super modern geo and the mullet still feels like it corners better ( stands up less) than the other bike.
  • 2 1
 @nvranka: as someone who only rides gravel paths and nothing more than green trails, I can guarantee you that a mullet setup has changed my world. I'm now a believer!
  • 7 0
 People have already pointed out the error with the means on the first track, but I was also curious about the claims of non-significance so I thought I'd actually chuck this into a simple model.

I used the raw data as shown above, but I dropped the slowest 29 lap time from track 2 as you dropped the slowest mixed time and I wanted to keep equal numbers for each bike. I chucked it into an OLS model with time as DV and wheelsize, track, and lap # (per track) as IVs.

You're right, wheelsize is not significant, with a p value of 0.23. However, that's not entirely surprising considering the sample size, so shouldn't really be given too much weight. We do see a a coefficient of -0.21 for mixed, so mixed wheels were, on average, 0.21 seconds faster when controlling for track and lap #. That does seem a bit small to really mean anything!

Both the controls are significant though. That the track is significant is the least surprising (they're very different lengths). However, the lap # is significant (p less than 0.01) even with this small a sample, with a coefficient of -0.11. So, on average, you were 0.11 seconds faster each subsequent lap you took on each track controlling for wheel size.
  • 4 0
 Good analysis!

The mean times were correct for each wheel size in the original post, but when the article first came out the 29" lap times were labeled as 27.5". Complete facepalm on my end (this is corrected now)

You're right, it's not surprising that it's not significant given the small sample size, but the statistical power is low (large variation within both 29" and 27.5" groupings and a small average difference) so I'd need to do a lot of runs to have any hope of significance.

As you say, the times got faster which makes things trickier. I think the "ABA" order I did the testing (even though I mixed-up which way round it was!) was a good way to minimize this, though alternating between each run would be even better (though more time-consuming)
  • 1 0
 @seb-stott: Ah damn, then this all goes out the window Smile

This was really a 5 minute model in R, so pretty simple (and a nice distraction to warm up my brain for the day). I think it should at the least include some interaction effects as well, but that starts to really add up the complexity for such a small sample fast! This did make me kind of excited about what you could do with this if you start including more data (HR at minimum would seem to make a nice control for rider energy/effort). I guess that's what the big teams are doing on test weeks these days!
  • 8 1
 Companies experimenting with wheel size trying to convince you to spend another 8k on a new bike. It may be better or not, the hassle of having two different wheels is not worth it for the average Joe, and the thing will disappear in a year or two.
  • 6 0
 ....hmm... better buy one just to make sure though.
  • 5 0
 I think his height played a big part of it. Being 5'9 and having a mullet, I feel it does tip over and faster and having the smaller wheel to accelerate faster really plays into my style and mindset. Then again, I don't ride over roots like that.
  • 5 0
 I certainly think that Mullet is the way to go for shorter riders. I mean if a 6'3" rider logged no time differences at all, mullet can only offer upside for mid sized riders and for that matter 29" size small bikes seem pretty silly.
  • 7 0
 I hate to be that guy, but your stats are wrong. The 29" was slower according to your own first chart.....
  • 3 6
 You are correct, he got the labels backwards on the first test. The Mullet was faster, and the difference was statistically significant. The t-test returns 6% statistical significance. In other words, if the bikes performed the same and the difference was due to random variation, a difference in means like the one observed would occur only six percent of the time. This is a good basis upon which to reject the null hypothesis (no difference in performance) in favor of the alternative hypothesis (there is a difference in performance). The Mullet was actually slower on the second course, also the opposite of what was reported. However, the difference was tiny and not statistically significant. Finally, he should have selected the bike for each run at random, like red or black from a deck of card. This would add to the validity of his inferences.

"There are lies, damn lies, and statistics." Mark Twain
  • 1 0
 @jacobyw: it should be a blind test. It would be easy on a bike like this and see if he really could tell the difference. And the courses need to be longer.
  • 3 0
 The labels were wrong in the table, but the average times were correct in the original post, so the 29er was faster on the first track. (This is a complete facepalm from me but it's corrected now). As pointed out above, it's not statistically significant (p=0.23)
  • 4 0
 The biggest difference isn't for the rider, it's for the frame engineers/designers. The extra .75" of clearance can provide room for more suspension travel, more optimized pivot points, better water bottle or tool affordances, more mud/fender clearance, etc. However, this has become less of an issue as we've discovered the benefits of steeper seattubes and longer chainstays, so unless 180mm+ starts becoming the norm or tolerable on trail/enduro bikes, I anticipate the industry shaking out 27.5" yet again and going back to 29".
  • 2 0
 Or a motor…

Spesh seem to have decided there is a magic 442mm chainstay length and ran it first (?) on the new Enduro, then on the new Levo, and now again on the new Kenevo SL.

A 29” rear would have required a longer chainstay on the Levo given the big motor so they went 27.5” rear instead to maintain the “magic”.

The fact that Spesh bounced back to full 29” for the KSL after going to a mullet for the Levo suggests there’s not much in it in terms of wheel size.

It does make you wonder though if there shouldn’t just be a flip chip that would allow either wheel size in the rear. Sell the smaller bikes setup as mullet and the bigger bikes full 29, but leave folks the possibility of converting to either as they see fit.
  • 5 1
 Aside from fit (being 5'9 with very short legs), the main things keeping me from the full 29r are the weight of the tires (I'm already at 1300g on a 650b EXO+ and insert), and the stiffness of the wheel. Any time I'm behind a buddy on a 29r I'm astounded at how much those wheels flex from side to side... you don't see that as much following a 650b or (gasp) 26"... I'll be ready for a new bike next season or the season after. I'm hoping that by then there will be a plethora of purpose-built mullet bikes.
  • 4 0
 I'm not sure what you're talking about, Seb. Half a second over a 50 second lap is quite a big difference coming from a single setup change while all other factors exactly stay the same. Over a lap of a DH race course that could amount to a 2.5 - 3 second difference. Thats a massive advantage for the full 29" setup. I'd even argue that the differences on a DH bike would be even more pronounced, since the speeds are a lot higher and the terrain is tougher.
  • 5 1
 i honestly think that some people here have very short term memories as the bike industry just keeps tweaking geo slightly each year with a slightly slacker head angle, steeper seat angle etc and most people seem to lap it up but i cant help thinking does everyone here ride full on dh trails only.....i honestly cant imagine riding any decent distance (30 miles plus) on a trail bike with a head angle much slacker than 66 degrees and enjoy it. my 2018 smuggler is a very long bike and its got a 66 degree head angle and it feels a bit of a pig in tighter turns and i honestly wouldn't want it any slacker. thankfully it only has 120mm rear travel (which still is a lot to me) and its way lighter than most other 2021 bikes in the same category. all i tend to see now are bikes on trails with sub 65 degree head angles weighing in the region of 15-16kg with 150mm or more travel and most riders do one lap of the local trails (10miles) and then drive home. i dont blame them i mean there bikes must feel like a boat anchor on longer rides. i feel like everyone looks at the extreme ends of the sport and assumes there hardcore riders too so they also need dhf tyres on there trail bike to ride xc trails and a 64 degree head angle when in reality they would likely be much faster on a light hardtail with 100 travel for and a 69 degree head angle.
  • 6 0
 Rear wheel size is one of the only bike things that actually could be tested blindly.
  • 6 0
 A 6'3" guy doing mullet testing, now get a 5'5" person to do the same test.
  • 2 0
 That's closer to the average guy so I would be interested in seeing the results.
  • 3 0
 I'm 5'8", and have been riding a mullet exclusively for about 5 months. Coming from a full 29 setup, it feels dramatically better in steeps where I no longer get tire buzz. My conversion also preserved the geometry (within a couple tenths of a degree HA and a few mm of BB height). I held onto the 29 rear wheel for a while, and just finally sold it because I've decided that I just have no desire to go back to inserting a DHR into my crack.

That said, I would like to borrow a friend's front 27.5 wheel to try similar "modern" geometry in a full 27.5 setup.
  • 3 0
 I also think the type of suspension your bike has a big effect on how mullet worthy it will be.

True High pivot ( Commencal, Forbidden) w/ at least an inch + of rearward axle path makes any rear wheel hang up a non-issue. Not to mention the lack a pedal kickback those designs have.

A more forward axle path design may make the small rear wheel downsides more apparent. Just my 2c.
  • 4 1
 9'ers are less forgiving of poor cornering technique, of that I am quite certain! They require more lean and more bike/body separation. I think this is why most pros seem to have no issue but many riders can't get 9'ers to corner exactly how they intend. Mullets help with this but the rear wants to take a slightly shorter radius vs the front which feels a little strange to me.
  • 2 0
 Agree with the conclusion, question the diagnosis. The issue is countersteering. Bigger wheels have more inertia, all things being equal, plus 29'ers have more BB drop, so they require more countersteering to initiate a turn and achieve appropriate lean angle. Search "countersteering a motorcycle" if you're interested in exploring this topic further.
  • 3 1
 @DirtCrab: Agreed! Countersteering and lean are closely related, which I've figured out fairly recently. Smile Also, the smaller wheels don't need as much lean/countersteer so you can get away with poor technique moreso vs 9'ers.
  • 3 0
 I think the biggest takeaway here is that shorter riders are not at any kind of meaningful disadvantage riding a mullet set up. If it’s basically the same speed for someone that’s 6 foot 3, it’s going to be faster for someone who is shorter and would have their positioning and movement on the bike compromised by a larger rear wheel.
  • 3 0
 Should compare a 29er to a mullet where, as with MX bikes.. .the rear tire is significantly WIDER than the front as well as mounted on a smaller diameter wheel. We have 27.5 plus tires afterall... this is possible to do... and the difference in inflated diameter of the tires will be less and require less of a geometry adjustment be made in the frame (which affects the shock curve slightly also).
  • 3 0
 I'm shorter rider (5'7") and the mullet setup is better for me. 29er is just better on the front for stack height and rollover and the 27.5 is better to avoid butt buzz especially in jumping. Mullet specific designs with mullet-specific geometry are welcome in my book.
  • 4 1
 It's funny that he mentions better turn in with a bigger front wheel.

1) Some of the first guys to really look at this said the advantage was in how it tracks THROUGH the corner. Not how it turns in.

2) Turn in will always be hampered by a bigger wheel. There's more spinning mass that's resistant to changing directions. The motorcycle world has understood this for years.

3) It has always occurred too me (for reasons he stated in the video) that a 29" back wheel makes sense as it's more resistant to hanging up.

So why not a reverse mullet? 27.5 would have a better turn in and 29 would be more resistant to hanging up in the tech (Or 26 front 27.5 rear for shorter riders). BUT this will have an effect on tracking through corners AND ghetto setups will immediately end up being steeper in the front end.
  • 2 0
 The spinning mass of a bigger wheel does have a greater gyroscopic effect which may make it harder to lean in or keep it leaned in. This is certainly true with motorcycles as you say, but the effect is small with bicycles.

For a given model of tyre and rim (as in this test), the gyroscopic reaction torque is proportional to the square of the wheel diameter. For a 29" wheel, the outside tire diameter is about 5% greater than 27.5", so the gyroscopic torque is about 10% greater. But this only makes as much difference as a 10% increase in rotational inertia, which could be achieved by swapping an EXO for a DoubleDown tire (roughly) or fitting a mid-weight (150-200g) insert on a 27.5" wheel.

So this 10% greater gyroscopic reaction from the rear wheel *might* explain what I was feeling on the faster turns, but if so the same goes for adding 150-200g to the tyre/rim. Either way it's not a very big effect.

As for reverse mullets, maybe there is some logic in that, but the larger front wheel is important to avoid tripping and pitching on bumps
  • 1 0
 @seb-stott: Great response dude! And I agree in terms of percentage. Is it noticeable? Probably depends on the rider. I noticed it when I went up a wheel size AND to a wide trail setup. I considered adding leverage (wider bar) for a short bit but I got used to it.

Considering the greater gyroscopic effect is easily overcome, let's move on to " the larger front wheel is important to avoid tripping and pitching on bumps". Perhaps there is something I'm not understanding here. It's my view/experience that this is a matter of both a sorted geo AND (perhaps more importantly) some compliance in the system. Starting first at the tire!

Are you implying that the greater gyroscopic effect will impart additional stability once leaned over and settled?
  • 7 1
 being 164cm tall, mullet for life!
  • 4 0
 Where did that guy's nose get to? Conspicuously missing from each photo. It must be one a them industry conspiracies I keep hearing about.
  • 7 1
 Mullet over!!! Should've posted on Sunday in honor of dad jokes.
  • 6 1
 26" front and 29" rear is the real future and we all know it, we're just scared to admit it
  • 2 0
 @litany
I absolutely agree - try traveling with this set up and you are bringing along twice the tires. For convenience alone, many of my bike decisions including brakes, drivetrains, wheel size etc. are based on what I already have and can service easily. I'm sure Magura brakes are awesome, but I have XT on 3 bikes...so no go for me. I finally went full 29" between my enduro/xc bikes just because you end up having so many tires sitting around with 75% or more life in them, that depending on your adventure, it becomes very handy to switch out as needed.
  • 4 0
 You don't have to be short to experience butt buzz. You could also be taller and ride steep stuff off the back like a coward. Don't ask me how I know that, I just do
  • 2 0
 I went to a 27.5” rear on my 2015 Tallboy 2 Carbon. Rode that about 10 times. Felt faster, but wasn’t sure. Went back to the 29’er and it was so much better! Just railed berms, and was much easier to ride.
Don’t know if this was geometry or centrifugal effect, but I swear it felt like it turned slower with the 29/29 set up.
Messing with good geometry can bite you in the ass..
  • 1 0
 Tallboy is a 110mm bike so not sure it applies here since this article is about long travel and shaving tenths off DH times.
  • 3 0
 @Snowytrail:
100 mm in my case!
I’m just talking handing balance alone. And I believe 100mm will show more of a difference than a typical trail bike. Baby steps change everything on that bike!
  • 6 0
 Now how about we compare dual 27.5" to mullet?
  • 2 0
 Second this!
  • 2 0
 I've been riding a Mullet for 6 years now. My fox 26er 36 160 fork will fit either a 26 up to 2.8 or 650b up to 2.3. I have both a 26er wheel and 650B wheel with the same tire.I run my favorite North Shore tire, the Maxxis dhf2 2.3 3c TR exo. I use Burgtec Titanium offset shock mounting bushings which allow me to adjust the head angle up to 1.5 degrees for fine tuning HA. 650B fits fine and has never had clearance issues with mud rocks etc I even have set it yup with marsh guard fender since I got it as well. That said with same HA via bushings mullet is faster but 26er is so much more fun
  • 2 0
 29 allows have more bb drop which leads in superb cornering and stability ;
I would say size specific approach to frame/wheel are the most proper way to go at least for general trail/enduro riding
12 -> 16 -> 20->24-> 26 -> 27,5 -> 29
  • 1 0
 The 27.5 looks redundant in this row #26isnotdead
  • 1 0
 Interestingly Seb Scott himself wrote here that the actual bb height matters for ride characteristics, not the bb drop : www.bikeradar.com/features/the-ultimate-guide-to-bike-geometry-and-handling
  • 2 0
 He mentioned it multiple times, blind test. This bike is a perfect candidate for it. They need to redo this with an average height person and a longer track. And make it a true blind test. Stick a GoPro on his helmet to make sure he doesn’t look at the back wheel/suspension, take 5 min between the runs at the top for someone the switch (or not) the bike, hand it to him and he goes. At the bottom first thing before he looks, he has to say what size he thinks it is.

A always wonder if they did this, would people be able to tell a difference with half the shit that we see tested? I doubt it. I bet, if you could block out the whole bike, over half the people on here couldn’t tell the difference in their own bike. You could take their bike, swap bars/grips and tell them it’s a completely different bike with different sized wheels. They’d get to the bottom and tell you whatever the stereotype about said bike is.
  • 2 0
 Not a racer but obviously like to go fast and check my times. I just feel that the plow factor up front and the quicker acceleration & higher potential torque on a smaller rear wheel helps me scramble up and over some techie terrain easier. I've been on a SB130LR and YT Capra 29 for the past 2 years or so and love these bikes. I then tried the Capra in the high setting with the smaller wheel and felt a little ore cramped in the reach department but more confident in going fast on blind runs on new steeps. I felt cornering in berms was easier too. I tried my new SB165 mullet a few days ago and same thing- boulder scrambles were easier- same stuff I might dab on while on my 130 was cake. It could all be psychosomatic, but at 5'8" w/ ape index of 1.06, I was definintely Flo Payeting my nether regions with the 29 wheel so the smaller wheel is better for me.
  • 2 0
 I'm actually disappointed about this article pinkbike. In the whole world with all the trails at hand you are doing a one minute run? In an area of England that has about half a hill? Just because of the journalists hometown?
I know it has been hard to provide news in the pandemic where not much is going on but this is not the mullet article anyone wanted or is in any way useful. How about an article on what bikes do mullet well that are not meant to be mullets?
You could of done a pandemic trail gopro with trail forks location, every day, submitted by us mortals or any number of other ideas! But nah we have Seb knocking out a minute on the most silly looking bike this side of the new pole.
I feel better now. Sorry for ranting.
  • 5 0
 This must be the new thing to sell
  • 5 2
 Geometry is pretty well dialed, 26" is dead, plus bikes were tried and died....not much else to market.
  • 4 0
 @the-one1: wut?

high pivot is selling like pancakes... maybe is not a bike related thing, but definitely geometry related, there will always be something new to sell.
  • 2 1
 @the-one1: Are you referring to plus size tires?

If so, the idea that they died seems strange since every other racing discipline that relies on science knows that compliance is king.

But the question of their validity has never really been explored to any real extent. Most of the time whether or not something gets a serious try in this industry seems to be more driven acceptability or popularity than actual science or understanding.

Example:

How long was it before 29" became regular in DH? Remember the uproar and bitching when Santa Cruz showed up at the season start couple of years agao (I think 2017) and all team members put in at least a second on everyone else? Remember how much Bruni bitched about it?

The point being that much of the time this industry is driven more by it's "idea" of what's cool and good and resists real research or facts as a result.
  • 5 0
 What's more fun is the question!
  • 4 0
 This, only the test needs to be redone to include 27.5
  • 1 0
 I propose we change the name from Mullet to Napoleon....If you have the complex you can ride the bike.... Also please repeat the test where you need to get on the bike blindfolded only to be removed once you start the ride and you are not allowed to look at the rear wheel. Blindfold is put back on before you get off the bike. How about adding a full 27.5 to the test as well....although for that you would need to ride blindfolded the whole run so maybe not such a good idea....
  • 1 0
 I'm down with the blindfold test, seems to me most bike decisions and casual shootouts like this are fraught with confirmation bias. Blindfolding these nerds could blow their whole thing up though, like wine tasting. I doubt they'll go for it.

As for Napoleon, we can't use that name because dude wasn't even short for his time. He was average height for a French man of the period, and surrounded himself with big guards who made him look shorter. Troy Brosnan was calling mullet/mixed wheels "hybrids" and he's the current fastest rider so we can go to that if you like. But we leave Nappy B out of this!
  • 1 0
 I'm not really really worried if its faster or not but for me a 297 set up felt better, I have short legs and always felt that 29ers while fast and stable at speed, is a handful in techie stuff and tight switchbacks, something our trails tend to have a lot of.
  • 1 0
 I played around with a mullet, because I couldn't get a 29" rear wheel for a few months in the pandemic times. On my bike, running a mullet in the higher BB setting is almost identical to a 29" wheel in the slacker setting. Mullet did have more of a slalom-y, dive Into and carve corners feel. That said, 29" still handles great and was clearly faster/smoother rolling on chunky climbs and anytime I needed to maintain momentum on a flat or uphill section. All butt Dyno, but it was pretty night and day for me. I think in addition to rider height, style/genre in terms of trail/all around vs. more gravity focused or winch and release type riding is going to be a factor, too.
  • 1 0
 Sincere question for the peanut gallery. I've a 29er DH bike, SC V10 - which is awesome, btw. (More sus. travel than I need for park laps, but that's besides the point.) My theory is that a mullet bike will help on jumps, more easily getting rear end to rotate?
  • 1 0
 You actually didn't ask a question there, but anyway go look at the new cdale vid with Mitch. It ain't the 29 rear holding you back.
  • 1 0
 As a shorter dude who enjoys shorter chain stays and have ridden quite a bit of both 29 and 27.5 I can say that I’m very interested in a mullet set up! My current bike is a 21 stumpy evo which has the option to go mullet but the chainstays don’t go super short so for me it’s not really worth it. I don’t know but I like the idea of gooner bike’s built for short dudes with short stays and short straight seat tubes and with good capable geo!
  • 1 0
 The main thing I am interested in is the acceleration, which was mentioned at the bitter end. Long long technical climbs, bit wagon wheels are more to push over. Every time I sit on a friends 27.5 bike I'm amazed at how sprightly it feels pedalling out of the gate. But, I don't build my bikes to climb, so there it is. .
  • 3 2
 I think the biggest advantage of the mullet configuration has been overlooked; they look totally bad-ass.

I go back and forth on my Trek Fuel. My bike park tires (Assegais) are on the mullet wheels. However, this changes the geometry on the Fuel. I think this is a beneficial for the park, but I prefer the 29er geo everywhere else.
  • 1 0
 A test on the same bike with 27.5" und 29" doesn't really work, even if th bike is adjustable to both wheel sizes. The reason is, that you have on such a bike more pedal kickback with the 27.5" wheel, which is a disadvantage. A real Mullet only Bike will work better. Or you have to do that test with an hp bike with idler.
  • 1 0
 First off, I love these techie comparisons. I find it all interesting but underneath the averages, here is what I find cool . ( apologies if already noted above )

Aside from swapping the avg times for track 1 as noted above ( 27.5 = 49.45, 29 = 49.9 )

That standard deviation looks like this 27.5 = 0.295, where as the 29 = 0.509

So if you look at standard deviation as a measure of the associated risk of changing track conditions and an estimate of the uncertainty of holding your ideal line, (if the sample size was larger enough to be valid) you could make the argument that the 27.5 bike was more consistent and that the 29 bike had more risk / fluctuation ( variance looks like 27.5 = 0.087, 29 = 0.26, roughly 3x more variance on 29 ) and perhaps more chance/precision required to get a fast time. E.g. is it harder to move back on line... up to speed, out of corners ? many factors.

All rubbish if your Greg Minnar and your only metric is the haul ass meter ...
  • 1 0
 I'm not being negative about what you've done here Seb, your methods seem robust, but please consider repeating it with riders of varying height. Perhaps Geometron would support you in providing a few different size bikes from their demo fleet.
  • 2 0
 Now do it with a downhill bike. Mullet seems to work best for DH as most top DH riders are riding mullet but most top enduro riders are on full 29". I assume the longer travel from the DH bikes makes but clearance even less
  • 1 0
 There’s not really much here that tells you whether a mullet is better for up and down flatter trail riding with a lot of roots, i.e. much US east coast riding. But then again Pinkbike rarely provides much information about how bikes fare for that kind of riding because none of the reviewers ride that (except maybe Dan Sapp). Personally I never have any kind of butt tire rub probably because my trails aren’t that steep. I never notice my 29 rear wheel being too large. If anything I notice the front is large, but you get used to it. Given the rollover advantage with 29, I doubt a mullet is better unless it feels significantly more maneuverable without getting hung up too much compared to 29 rear. So count me skeptical but I can and will try it at some point.
  • 1 0
 Wait a minute. Earlier you were telling me that mullet keeps the mobility of 27.5 and the roll over of 29 because the front wheel matters more. Now you're telling me that the rear wheel makes more difference in carrying speed??? Goddang it, I'm going to have to go buy a new $6000 bike next year!
  • 1 0
 It might be more interesting to compare a bike made for mullet only with a full 29er. Because a bike made for both will probably have compromises made in its geometry and construction to allow for both wheels to work with a similar geo. But in the end the differences are probably very small and come down to personnal preference more than intrinsic speed.
  • 1 0
 cool video and i agree that if your shorter in height and ride a dh bike i can see a 29er getting in the way but apart from that the whole reason 29ers even became a thing was because they roll over terrain better.....thats literally the whole point to them so yep if you can run a 29 setup it would surely be the best choice in all disciplines.
  • 2 0
 Let's get the lankiest journalist working at Pinkbike and ask him to test a setup known to work for shorter riders on a bike which wasn't designed as a pure mullet. Not a very informative test but hey the comments blew up!!!
  • 1 0
 I ride a mullet on my trail bike with corrected Geo from 10mm flip chip on Trance X 29er- not for speed as much as playfulness, especially hopping trees or popping quick jumps etc. Though in some circumstances that could be faster, too. I felt an instant difference because of the axle to BB height relationship. With 29er the BB drop is significantly lower than with a corrected 27.5 rear which I feel makes bunnyhopping and quick pops much easier but I still like the monster truck advantage of the big wheel in front. Certainly on faster flowier tracks and/or mashing through root gardens like this test showed Im sure its a wash or a little smoother on the full 9er. ..... For me and techy tree filled trails the mullet is a WIN.
  • 1 0
 Nice One @seb-stott incredibly relevant at the moment! I really like how you hypothesize about why others might really find a big difference between the two setups and that, perhaps, it's not the rear wheel size that's making the difference but some other parts of the geo that changed because of the change in wheel size.
  • 4 0
 Pop corn here. I ship worldwide.
  • 5 0
 Which is funner?
  • 6 2
 its always more fun partying in the rear Smile
  • 7 1
 27.5 F/R is more funner
  • 3 0
 @crazyXCsquirrel: Thats actually the funnerist
  • 6 6
 I don't understand why most of the women on the World Cup circuit ride full 29. For example Vali Holl is 5ft 3 and she rides full 29. Reece Wilson rides mullet and he is 5ft 11. Wouldn't full 27.5 be faster for people under 5ft 6? In gravity sports the rolling speed of 29 barely matters. The ability to hop between lines, hit huge drops, and scrub jumps is way more important. It is only logical that short riders ride mullet or full 27.5.
  • 1 1
 I would tend to think this way as well but sometimes technique seems to overshadow expectations like this. For example, I rode with a 100mm dropper because that was the max the frame fit and didn't like it because not enough drop. My comrade rode with a dropper but didn't use it and had no reason to complain. We were the same height. Was a bit perplexed by that in the same way.
  • 1 1
 I bet the weight and strength of men vs women or even large riders vs small riders come into play here. A smaller rider might prefer the ability to carry more speed, because they appreciate not having to pump as hard to regain speed. whereas Reece has enough inertia on a steep track to not have to worry about that much, and is all about cornering performance or something.
  • 2 0
 So, someone who rides 29ers and always had a preference for 29ers when at MBUK, is slightly faster on a 29er. Not much of a surprise really. JP
  • 1 0
 Also realize that putting a 29er front wheel on increases the trail value and changes the steering. If you like a quicker steering bike, don't forget to either increase the offer or simply stick with a 27.5 front wheel.
  • 2 1
 the test should be done into a track not to steep not easy to get speed cause very rough. Is where you notice the most the big wheel how allows you to carry speed over smaller wheels.
  • 1 0
 I'm sure the industry will find more configurations, offsets, or angles that we must have for next year. At least for the most part bikes are getting more capable, especially due to geo and suspension improvements.
  • 1 0
 Seb, you have the average times swapped in the article above.

According to your published times the 29er averaged 49.9s & the Mullet average 49.45s being the faster setup.
  • 2 0
 I'm glad I don't ride BMX and MX I'd have nothing to talk about when it comes to wheels! What a load of pish! Wait till they bring out 30" wheels, so much faster! Feck off
  • 1 0
 They tried to bring in 22' for BMX, glad that never took off. Just shitty "pros" who were never good with a 20', trying to be the big fish in the small 22' pond.
  • 3 0
 As a 6'-3" 220lbs Human, I enjoyed the implied comment of anyone under 6' being small.
  • 3 0
 The industry really wants to kill the 275 wheel size that they always have to prove 29ers are better. I hope they fail.
  • 1 1
 What track 1 shows is that the 29er had a flying start due to the test method.
Then the unrecorded results from the 29er are effectively included in the 27.5 results.
The 27.5 then overtook the 29 with the 49.1
Going back to the 29 then resulted in a slower time, followed by a 49.1.
This results in a significantly better SD for the 29er.
I am not a stats guy (but I do work with them), if you use a p value into the equation for a confidence level of 95% the 29er stomps it.

But.... The test method might not be the best.
  • 2 0
 Excellent timing. I totalled a 29" rim over the weekend, was considering re-building with a 27.5" to try a mixed set-up but sounds like there is no point. Nice one Seb.
  • 4 1
 what a surprise - fuck all difference
  • 2 0
 I don't think it's only about speed. It's also about what setup lets the racer/rider feel more confident in the bike.
  • 1 0
 This is going to make the santa cruz CEO who put a 29 wheel on an old bronson and charged 12k and called it a new bike pissed.
  • 2 0
 So the takeaway is bigger wheels for taller riders, but ultimately it's subjective. Earth-shattering news.
  • 1 0
 In theory, everything should be relative to a riders size, but that's not feasible. I mean, it's not like a size small t-shirt has the same size sleeves as a size XL, but only the trunk of the shirt is different. So inevitably with bikes you are often too small or too large with some measurement; occasionally its "just right". I firmly believe there's no 29 is better or 27.5 is better or mullet is better. It's all about the rider size and their style. But yea, this guy at 6' 3" doesn't shock me that he's all-good with the 29er.
  • 2 3
 "but it seems to take less effort to lean into the turn. I don't think this is necessarily “better”"

Go ahead and say it's better. Isn't that the whole point? Turning is a huge part of riding bikes. You didn't find any statistical benefits on timing for those particular runs, but anything taking less effort is almost always a good thing. Isn't that the point of everyone shouting about "pedaling efficiency" and anti-squat and such: little bits of "less effort" adding up?
  • 2 0
 Less effort to initiate the turn means more effort to hold the same line. It's simply less stability. Whether that's good or bad depends on the situation.
  • 1 0
 I ride a Geometron and I appreciate that it takes more input to initiate a turn. That means I can ride/turn through rougher sections without being put off line as easy as a less stable bike. Seb could have also worded it as the full 29er taking less effort to ride a consistent line through corners and straights.
  • 1 1
 @jeremy3220: Holding a line has more to do with tire grip, wheelbase, suspension, etc. Just because it's easier to turn in doesn't mean it's going to be easier for the terrain to stand you up. It's like the way a worm gear driving a spur gear can't be back-driven.

Also, easier to turn (in or out) means easier to make small corrections if/when the terrain upsets the bike. If your tire gets pushed to the side by a loose rock or a root more slippery than you thought, a bike that takes more effort to change lines is going to take more effort to back on the original line. If someone is about to get stood-up and high-sided by a bad line choice, a slight increase in turn-out effort is probably not going to save them, but less effort needed to adjust the turn might allow them to make a small adjustment and not get stood-up.
  • 1 0
 @justinfoil: There's not only the gyroscopic aspect adding to the 29er's stability. With a given BB height a small wheel means the BB to axle is less negative, this decreases side to side stability. So a 27.5" bike is definitely less stable in the corner.
  • 1 0
 @jeremy3220: Do bikes lean from the axles? Or from the ground? Answer: it's the ground. So, what does the BB being further below the axles, but the same height off the ground, have to do with leaning, if the lean starts at the ground?

Not saying more BB drop on big wheels isn't good for something, but it's not leaning.
  • 1 0
 @justinfoil: BB drop increases stability, makes it harder to lean. BMX bikes have their BB higher than the axles which makes them very nimble but good luck holding a line on a rough corner with a positive BB.
  • 1 0
 @jeremy3220: BMX bikes have their BB higher than their axles because the axles are very low and a BB lower than them would be very tough to pedal. Holding a rough line doesn't depend on BB drop or rise, it depends on BB height from the ground, because _the bike leans from the ground, not the axles_.

BB drop or rise with respect to the axles has impact on endos (front axle to BB, both height and distance), and manuals (rear axle to BB, both height and distance), not lean.
  • 2 0
 @justinfoil: You lean the bike using the pedals and grips though. You can't have you're cake and eat it too. If you make an input easier to initiate then the reciprocal effect is that forces at the other end are easier to affect you. This is true of everything on the bike. Narrower bars are quicker to steer but easier to be thrown off line, shorter chainstays are easier to get the front wheel up for a manual but harder to hold it, etc.
  • 3 0
 When I go out on a 2 hour ride I do not want to finish in 1:59.59.9!!
  • 2 0
 So there’s not much difference between 27.5 and 29. Who would have thought?
  • 1 0
 Talk about burying the most important datum! 20 laps and only the mullet caused a crash. Clearly 29er is better! Pick a 29er and be a dick about it.
  • 2 0
 Next time please ride the bikes in the ^ ^ v v > > B A Start pattern please for more accurate results.
  • 1 0
 @sweatypants

That would only work for the first 99 tries, unless you’re just being a Contrarian…
  • 1 0
 if you're not a pro racer counting miliseconds, this topic is kind of mute.. ride what you like, to quote the great Rick Sanchez: think for yourselves don't be sheep.
  • 1 0
 Hear me out, what about a freeride mullet, 27.5 in the front and 26 in the back. That’s the ultimate have fun and go kinda fast bike!
  • 1 0
 Just put a 3.0 tire to your front wheel and keep the rear nice and reasonable. Boom, squishy mullet.
  • 1 0
 Give it another 5 years....
  • 1 0
 Pretty sure Zink did this at Rampage.
  • 1 0
 Two-tailed Student's t-tests, 2-sample assuming equal variances, gave a p-value of 0.234 on test 1 and 0.906 on test 2. They are statistically identical.
  • 1 0
 Two big Problems, a tall rider abd why must have the little backweel the same geometry like the full 29? That make no sense...
  • 2 0
 This is quite interesting.
  • 2 0
 Cool. Track #1 27.5" average time is not match the lap times shown.
  • 1 0
 There is a typo in the table for the first test. The 27.5 setup has the lower number (49.45) not the 29er.
  • 2 0
 The OCD in me is relieved.
  • 2 0
 Conclusion: It all comes down to rider preference.
  • 6 4
 Correction:

It all comes down to industry marketing
  • 2 0
 Tall guy prefers longer bike. Color me surprised.
  • 1 0
 Lololol...in the “early days” it was a 24x3 gazzalodi in the rear and 26x3 gazzi on the front.
  • 2 1
 I'm 6'5" and prefer a mullet or full 27.5 for racing. Personal choice but I don't feel comfortable on full 29".
  • 1 0
 2 tire sizes, 2 tube sizes, 2 (or more spoke sizes), 2 hoop sizes... too many reasons to say no considering this test.
  • 3 0
 Fcuk the 29
  • 2 0
 Seriously PB are you going to make the same stupid video every year ??!?
  • 2 0
 I remember the good old days when big-small wheel bikes were called 69ers
  • 1 0
 I'm a skinhead and reckon it's faster than a mullet. Although mullets do look awesome
  • 1 0
 Anecdotal and nothing more. We already see results of teams and pros testing and it's a mixed bag as is.
  • 5 5
 50 and 20 second 'tracks' and you're making declarative statements about results? hahah
  • 3 0
 Far far better to have shorter tracks and multiple runs for this type of comparison.

Oh wait, sorry, were you saying 50 was a bit long?
  • 2 0
 @JKL250: I think he was saying 50 is too short.
  • 2 0
 That's a fair point, but at what track length does the risk of line error, or rider error start skewing the results?
  • 2 0
 This is pb. We prefer our declarative statements based on groupthink and what the one fast local guys rides!
  • 1 0
 @VtVolk: Very true but I don’t think we need limit your comment to pb! We could expand that out to pretty much the world of many sports.
  • 1 0
 @nouseforaname: it not one length, just a sliding scale. The more variability between point A and point B the greater the chance of results being skewed for a test of this nature.
  • 4 0
 I think short tracks are better because you can do more laps with less time between each one. That makes it easier to feel the difference and gives you more times to check for consistency and do some very basic statistics (even more runs would be better for that).

Also, I am not trying to make any declarative statements about results. I said the difference in the times wasn't statistically significant and I couldn't feel much difference, but that other riders might. I can't think of anything much less declarative than that! Wink
  • 1 0
 your Track 1 averages are backwards
  • 1 0
 I'm just here for all the ABBA references
  • 1 0
 Ugh we were so close to a full 27.5" vs 29" vs Mullet test!
  • 1 0
 its been done before in fact even with a 26 included and a full 27.5 came out last bike radar did this back when all the wheel size debacle first kicked off.
  • 1 0
 @rabidmonkfish: It's been done a million times, but to my knowledge this is the first time that it could be done with a bike that can have an identical geometry with both wheel sizes.
  • 1 0
 Huh, not for me, needs at least 2 water bottles
  • 1 0
 And it's all marketing bull..go ahead jump on the latest trend lemmings
  • 1 0
 Unable to feel the difference in a blind test? That's ridiculous.
  • 1 0
 At least we all can agree that 26 is dead
  • 1 1
 But which one is more playful-er?
  • 1 1
 What about climbing? Oh! I forgot...
  • 1 0
 Mullet is more fun.
  • 1 1
 This angers me
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