Video: Are 29/27.5" Mullet Bikes Faster Than 29ers?

May 6, 2019
by Mike Kazimer  


Mullet bikes. 97.5ers. Frankenwheelers. Whatever you want to call them, bikes with mixed wheel sizes have made their mark in the racing world this season. Martin Maes took home the win at the first two stops of the Enduro World series aboard a modified GT Force, and Loic Bruni rode his way to victory at the first round of the DH World Cup on a prototype Specialized.

Now, this isn't the first time we've seen mountain bikes with two different wheel sizes. Specialized's Big Hit from the early 2000s is a memorable one, with a 26” / 24” wheel combo. Travel even further back in time and you'll find the 1987 Cannondale SM800, which was available with a 24” rear wheel that was claimed to deliver “superb traction.” Don't forget Trek's 69er, a 29” / 26” singlespeed with a dual crown Maverick fork. More recently, Liteville and Foes have both produced mixed wheel bikes. Needless to say, it's not a new idea, but the fact that they're winning races this year makes it a good time to revisit the concept.


The 1987 Cannondale SM800 was available with a 24" rear wheel.
Martin Maes' 29/27.5" GT Force.


Is there a reason we're seeing so much experimentation all of a sudden? The recent UCI rule change is one possible answer – riders no longer need to have matching wheel sizes in competition. That means shorter riders who can't quite fit on a 29" downhill bike can run a 27.5" wheel in the back, thereby preventing uncomfortable tire-to-pants contact, while still getting the rollover advantage of the bigger front wheel. What about Martin Maes? He may genuinely prefer the ride of a bike with two different sized wheels, or it could be that GT doesn't currently have a long travel 29er in their lineup, and creating a mullet bike was the next best solution until they come out with one.


The mixed-up Rocky Mountain Instinct BC Edition.


In any case, we decided to head out and put the concept to the test against the clock. A Rocky Mountain Instinct BC Edition served as the test platform. In its stock 29” configuration it has a relatively high bottom bracket height and a not-so-slack head angle, which made it a prime candidate for a smaller rear wheel. That change dropped the BB height by 12mm, and slackened the head angle by approximately 1.5-degrees.

It's worth mentioning that not all wheel swaps will be this easy – if you're starting with a 29er it's possible that running a 27.5” rear wheel will lower the bottom bracket height too much, and you'll be smacking pedals on even the tiniest pebble. The inverse is true when it comes to 27.5” bikes – the bottom bracket and front end height will get higher when a bigger wheel and fork are installed, which isn't always a good thing.

Once the test bike was ready it was time to knock out some laps. A section of trail was chosen that had a good mix of terrain – tighter turns, short, steep chutes, along with some flatter, more rolling bits. Each lap was timed with a Freelap system and recorded on a GoPro for backup. I started on the Instinct BC in its 29” form, and put down two timed laps. Next, I switched out the rear wheel and did two more laps on the mixed wheeler. To finish things off, I did one more lap on the 29er, then a final lap with the 27.5” rear wheel in place.



LAP TIMES
Lap 1: 1:41.12 (29)
Lap 2: 1:42.01 (29)
Lap 3: 1:41.06 (Mix)
Lap 4: 1:37.92 (Mix)
Lap 5: 1:37.55 (29)
Lap 6: 1:37.50 (Mix)


If you've watched the video, you'll know the result... There wasn't a definitive answer. All of my lap times were extremely close, and my two fastest laps were only separated by .05 seconds – it takes longer to blink than it does to make up that difference. To me, that reinforces the fact that it's possible to win with either wheel configuration. I do think that running a 29” wheel up front is superior to a bike sporting two 27.5” wheels, at least when it comes to racing.

The times may not have revealed much, but it was interesting to go back and forth between the two setups. The difference in handling is noticeable, but it didn't take long at all to get used to whatever setup I was on. It felt like I could maintain speed better in the flats and while pumping through sections of trail on the 29er, while the mixed setup felt better in the steeper sections of trail. It was also easier to place the smaller rear wheel where I wanted, whether that was in a tight turn or wiggling through a jumble of roots on a climb. Of course, the slacker head angle and lower BB undoubtedly played a role here too.

Is the 29” / 27.5” combo the future, or is it just another trend, a blip on the mountain bike radar that's going to fade away like Plus tires? It's hard to say, but I do think the concept has merit, especially for shorter riders, or riders in search of different handling characteristics. 27.5” wheels aren't dead, but their days of getting to enjoy the view from the front could be numbered.





MENTIONS: @pinkbikeoriginals



364 Comments

  • + 110
 Conclusion... drink the cool aid if you want to.
  • + 11
 I have 26" ; 24" and I would do without it given the choice.
  • + 8
 @Naturel: foes and liteville have mixed analog bikes. Canyon, YT, Bulls and several others have mixed ebikes.
  • + 36
 Kool...not cool. MURICA
  • + 12
 The wheels on the bike go round and round....
  • + 3
 Said Jim Jones.
  • + 13
 These are Tellum bikes, not Mullets.
  • - 10
flag endurocat (May 6, 2019 at 10:00) (Below Threshold)
 @Naturel: NS Bikes has been selling the NERD HD already for a little more than half a year. Do your homework before posting.
  • - 7
flag endurocat (May 6, 2019 at 10:33) (Below Threshold)
 @Naturel: They sell bikes in every continent.
Im sure you knew this before making your comments.
  • + 4
 @Naturel: Only a matter of time. And if PB are covering / pushing then its closer than you think.
  • + 23
 Talking of wheels, has anyone tested several different hubs for how much difference in DH race times can free hub drag and pawl engagement angle make?
  • + 2
 @WAKIdesigns: I am pretty sure there are the ones that work with 27.5 rim better than 29ers and vice versa...
  • + 9
 @Naturel: The marketing and coolaid comes next year obviously... Racers test it, ask for bikes to race, brand makes said frame for race, then needs to justify the expense so they start selling it, its a pretty standard series of events that plays out on repeat.
  • + 18
 Breaking news: Liteville and Foes revealed to be UK brands all along.
  • + 7
 Foes has been making the mixer for like 4 years now. @Naturel:
  • + 23
 Conclusion... "Go ride your f**cking bike..."
  • + 14
 @Kramz: i have 29 / 24 and are I am Living the Dream tup
  • + 1
 --
  • - 1
 @Purpledragonslayer: Analog.. lmafo nice try. You ain't Kool like Kazimer and "downcountry". Lol sorry not going to catch. It'll always be mtbs and ebikes
  • + 5
 @DirtMcGuirk07: or how about mountain bikes and mopeds? Analog bikes? Please!
  • + 7
 @Allen82: A mountain biker and a roadie are in a bar.

'Man, you guys take yourselves so seriously. Millimeters here, 0.5 angles there, 1psi more, carbon this, Strava that. Just have fun and ride your f**king bike.'

The mountain biker finishes his drink, gets up, pushes in his chair and looks at the barman,

'What's this guy's problem?'
  • - 1
 @Naturel: the only company I have seen trying to push the whole odd wheel size thing is NS I'm sure they have a bike called the nerd that has a 29" on the front and 27.5" on the rear instead of the other way round but then again NS are hardly your conventional bike brand
  • - 3
 @dubod22: that would be true if it was a BMXer talking to a MTBer. Roadies are even more pedantic about Strava and tech. They think that on an amateur race having Dura Ace instead of Ultegra or 105 makes a difference between successful and failed sprint attempt. Remember than Di2 was born on road... that says it all.
  • + 9
 @WAKIdesigns: That's the joke.
  • + 4
 @WAKIdesigns: I don't know about that. Mountain bikers aren't that far off. Plus the amount of variables on a mtb might even mean mtbers surpass that of the road-loving kind. Road bikes are pretty settled on geometry and wheel size but think about wheels on a mountain bike alone and we already have material choice, wheel size, wheel width, tyre tread, tyre compound, tyre width to name a few.
  • - 1
 @kieran: It's not Kool aid, but it looks cool. Imagine riding a downhill bike designed around a 29" front tire and 24" rear, it would probably be more fun.
There has been some renewed interest in the 24" rear wheel lately, not for racing just freeriding. Unfortunately Gazzoloddi is gone and there is only one remaining 24" DoubleWide for sale in the world.
m.pinkbike.com/buysell/2185745
  • + 2
 @RedBurn: Low...ride...aaar! Ass dropped!
  • + 0
 If it's that close, I'm going same size front and rear for aesthetics. Those mixed bikes look weird.
  • + 8
 @dubod22: Smile the only pretentious thing BMXers have is an expensive key chain hanging out of tight jeans. They even pretend they can’t afford a helmet! Everything roadie is pretentious. Everything. Cheers Wink
  • + 2
 “Is there a reason we're seeing so much experimentation all of a sudden?“

Yes, because we’ve already sold everyone 27.5 and 29, behold the best of both! The UCI admitted they only changed the rules because the bike companies asked.

If you’re a cynic, it’s because they want to sell bikes. If you’re an optimist, it’s because they think it’s faster.
  • + 2
 @Altron5000: Or maybe you can make a 27.5" rear wheel more durable for DH purposes, wider & have more ability to maintain low air pressures without flatting than you can with a monster rear wheel?
Or maybe cause there are 5'3" pro women XC racers or maybe it was a rule that just didn't have any scientific reason for existing.
  • + 1
 @Naturel:
Liteville does it. Educate yourself.
  • + 67
 at the begining of the video you mention the option for teams that do not have a dedicated 29 bike to use a 29 front wheel but you only tested the 27.5 as a rear wheel on the 29er? should this not have also been repeated with the swap in of a front wheel (and fork) on the altitude frame? Basically interesting to know if mixed wheel is a benefit over a 27.5 bike?
  • + 9
 Same question here
  • + 15
 We put the 29 vs mixed head-to-head in this experiment because that’s what we’re seeing more of in the racing world. There aren’t too many racers switching to smaller wheels.

There’s certainly room for more testing / experimentation, but I’ve found that my times with 29” wheels tend to be faster than with 27.5” wheels.
  • + 98
 @mikekazimer: I think the question is: Why did you not put a 29er front wheel and fork on a 27.5" bike.
In a sense, why did you make a 29er worse and not a 27.5" bike better?
  • - 2
 @mikekazimer: SCIENCE!
  • + 32
 @pyromaniac, well, it’s a lot easier to swap a rear wheel between laps than a fork. This made it possible to get the timed runs done more efficiently. The geometry of the mixed wheel bike is still similar to what you’d get by putting a big wheel on a 27.5” bike. Every scenario is going to be different regarding geometry - in this case we went with what was the simplest way to compare the effect of a wheel size change.
  • - 24
flag chriskneeland (May 6, 2019 at 7:50) (Below Threshold)
 Next test comparisons should be 27.5 vs mixed bikes. I'm still not buying the big wheels offering any benefit up front.
  • + 21
 @mikekazimer: I know, but still it's not reeaallly the test you suggest it to be at the beginning...if we're pedantic.
  • + 7
 @mikekazimer: For these tests I really think that any kind of statistically significant results (first of all nearly impossible to get anyway) would be better suited to a much longer lap time. When one or two seconds make a big difference, that's not saying much about the bike when other really small (non-bike) factors can have such a large impact. It makes it harder still when the actual bike change is so slight—we're talking about tiny geometry, weight, and other physical alterations. A longer lap, maybe nearer to 4 or 5 minutes and more total laps would help smooth out some of those other "daily" confounding factors and allow you to be more convincing. More data more data more data.
  • + 12
 @A-HIGHLY-EDUCATED-PROFESSIONAL, possibly, although it’s also a lot harder to put down consistent lap times on a 5 minute track. But yes, it’s definitely an experiment that would benefit from more data.
  • + 2
 @mikekazimer: You should be keeping the same Axle-to-crown as the 27.5 spec. You will also need to increase the fork offset on the 29 fork.
  • + 6
 @mikekazimer: It sounds like you enjoyed riding the bike better with the small rear wheel and times were no different, yet you seem to prefer running 29 f&r. Maybe I speculate too much. I love this concept, because I had little interest in 29 before people started reviewing this option, now it seems like you get some of the benefits without all of the negatives.
  • + 9
 The one thing missing (maybe I overlooked it in the data set) was your height @mikekazimer & most importantly, your inseam.

I'm 5'10" but I've got short legs & a long torso & 29" rear wheel will eat me alive.
  • + 6
 @bizutch, I’m 5’11” with a 33” inseam. I don’t typically get tire buzz on 29” trail bikes, but it happens occasionally on 29” DH bikes.
  • + 4
 I am going to try this on my Supreme sx. 29 Bartlett 190mm front fork and leave the back 27.5
  • + 2
 @mikekazimer: How about trying different tyre sizes with different wheels sizes just because you can?
  • + 5
 @pyromaniac: As silly as these comparisons are, I think the way he did it was ok. I would argue that the changes in geometry between different chassis make more of a difference than the wheel size. If you test different wheel sizes (or mixed) on different bikes, are you really identifying differences between the wheels, or the bikes? Even for manufacturers that offer both a 27.5" frame and a 29" frame in the same bike, the geo is usually not exactly the same, making exact comparisons, and thus meaningful conclusions difficult/impossible.
  • + 8
 @mikekazimer: dang. I've got a 30" inseam at 5'10"/ my torso is so long I have to wear size Large shirts so they aren't midriff shirts.
So this is a perfect illustration of how fitment on bikes & wheel sizes is so rider dependant. So the difficulty with me when I rode the Yeti SB150 was that I can't lower my body's center of gravity low enough to really have an effect on the bikes direction without flossing my colon with 3C knobbies.

My mass is in my torso & is just stuck up high several inches higher than someone like yourself. I can't make a 29" rear wheel change direction as easily. I have to throw a ton of upper body lean into every transition and turn.

You can drop your butt down more, clear the tire & push your center of mass down lower, gain a better lever on the 29" wheel & not force yourself to be top heavy in turns.

A great visual is a bowling pin. Very stable when leaned side to side and easy & quick to get it to return to center & stable. Turn it upside down & sure, you can lean it over side to side, but getting it to stay balanced & doing it quickly, let alone trying to return it to center is tough.

I'm always going to lean toward a smaller wheel in the back. Sure, if there were no steeps or switchbacks, I could drop in on a 29'er, but then I'm like a grade schooler on a set of 235 skis. Big Grin
  • + 4
 @mikekazimer: You need to use a power meter and use that to 'normalise' your effort which will always vary.

Looking at the times you posted. They look like what I'd expect even if you hadn't changed wheels. With second time being slightly up on first as you had just reminded yourself of track, then after that getting slower as you rode more and fatigue set in.
  • - 17
flag adespotoskyli (May 6, 2019 at 9:29) (Below Threshold)
 @mikekazimer: all this, you know, it's what's wrong with the bike industry...
  • + 29
 @adespotoskyli, experimentation is what's wrong with the bike industry? I'm not sure I get your point. As you can see by that SM800, companies have been trying things like this for decades.
  • - 14
flag adespotoskyli (May 6, 2019 at 9:42) (Below Threshold)
 @mikekazimer: you have answered your own question, key words sm800, decades, incoclusive results, to many variables to count on
  • + 1
 @bizutch: I'm 5'8"ish. I definitely get the buzz once in a while, more than the 27.5, but it just reminds me to get my ass more forward. There's never been a situation where I got buzzed and I couldn't have been a bit more forward, especially with the 65.5* HA.
  • + 4
 @mikekazimer: I agree with the criticism of you putting a smaller rear wheel on a 29 bike. Is anyone doing this? It's always the reverse, I believe. My guess is it would screw with the geo and suspension too much. You should grab a bike like the Capra or Mega that are available in either wheel size and do the test as the mixers are actually being run.
  • + 2
 @Climbtech: It certainly wasn't wrong altogether. But I would think kinematics and that stuff differ for different wheel sizes, so it's not really fair to put a smaller wheel in a big-wheel bike.

And I was expecting at least some comment regarding the arc the wheels take around a corner. A smaller rear wheel will turn on a smaller arc than a big rear wheel. Therefore turning will feel easier and 'more natural'.
  • + 1
 @mikekazimer: should have used a Scott ransom
  • - 1
 @mikekazimer: match the 29er with the slacker head angle and lower bb to match the 29/27.5 bike then put against the clock to see the 29 go quicker.
  • - 2
 @imajez: absolutely agree, dunno why they even bother without powermeter...
  • + 4
 I'd also prefer to see a 29'r put on the front of a 27.5 bike. While any difference in lap times is interesting...the more important feedback for us non-racer's(majority)...would be in regard to the differences in handling, trail feel and if it's worth bothering with vs dual 27.5.
I have a 27.5 Trance I'm considering putting a 29 front wheel on with the same 150mm travel..or maybe 160. For the precise reason anyone would consider doing such a thing...slack it out a bit and potentially smoother rolling up front as a bonus. I'll already drag balls on all the steeps I can find with 26 or 27.5...so not interested in 29'r rear, ever.
  • + 4
 @loopie: I raced my bike in all three configurations and prefer 27.5/29 for it's nimbleness and balance f/r. It's important to maintain the same axle to crown when going from 27.5 to 29 Front. I have 2 years of experimenting and have tried nearly every permutation. PM me and I can fill you in.
  • + 2
 @mikekazimer: Think there is your answer all along. It does not matter what is the tool, its the environment and trail style (requiring DH style tool) that's the deciding factor. If im riding trail, or tall ride 29. If im riding gravity and gnar, and am shorter 275 is da go. As Enduro and DH is the latter, answer 275. If riding trail and not so gnar. 29 is ya float machine..
  • + 1
 @downcountry: interesting, could you post a few basic specs please?
  • + 3
 @loopie: we've got a Staff Ride coming up with a 29er on the front of a 27.5 bike. We'll see what kind of more nuanced impressions come back from longer term riding.

I think for bikes with a low BB, or the ability to throw in an angleset, then a 29er front end can make a lot of sense to try. But bikes with a high-ish BB will probably feel a little strange.
  • + 3
 @downcountry: Certainly makes sense to watch the axle-to-crown aswell if making these mods...it would factor into the geo changes...
  • + 1
 @mikekazimer: Do the test on predator. on non-rainy days my times seem to only vary by 1% and I've ridden it a lot. It would be way easier to tell a difference on something that long.
  • + 1
 @pyromaniac: Exactly!
@mikekazimer: What we thought we were reading isn't what we got. Some companies aren't investing in making a new 29'r DH or EWS bike, so racers and race managers are taking that into their own hands and making frankenbikes.

The valid test would have been two of the same bikes. A 27.5 specific bike, vs. the same bike with a new fork and 29'r front wheel.
  • - 6
flag rideone62 (May 6, 2019 at 15:46) (Below Threshold)
 @mikekazimer: garbage. Why waste yours and our time? “cause it’s easier to swap a rear wheel”. Makes no sense
  • - 1
 @loopie: This needs to be done systematically. This whole "I'm gonna throw it on the back, and then throw it on the front" is classic. If it was that easy, the big manufacturers would have figured this out a very long time ago. It really shows how little the Design Engineers know - you also need someone who can understand the relationship between the parameters to truly define how we move forward. Looking a EWS guy who has better results means very little. He may have outdated geometry and it makes the bike a little better - you don't see many designing bikes around the R&D efforts. This isn't Formula 1...these guys have 1yr to make something better before it hits production numbers that can't be backed down. Most folks on here see it as better / worse.
  • + 7
 @mikekazimer: You could have just slung a 29 fork on a 27.5 bike and swapped out the front wheel only. That's even easier than a back wheel change. Even more efficient.
  • + 1
 @typrattmtb it was my suggestion to go with the Instinct BC and put a smaller wheel in the back. The chain stay length (435mm) is similar to what Maes has on his Force (433mm). As @mikekazimer pointed out, the Instinct BC has room to adjust to a lower BB.

Additionally, taking an Altitude and raising the BB and reducing the reach by installing a 160mm 29 fork and wheel is backwards to what knowledgeable riders would want. You could opt for a 150mm fork and an angleset but that is still not going to get you back to a reasonable BB height, which I feel is more important for handling over a larger front wheel.
  • + 1
 One should try a few laps on one of those really long downhills with a group of riders. Each rider does a handful of laps with no chain. They switch the wheel only, or the fork, or whatever. Surely the difference would be amplified on a ten minute lap.
  • + 2
 @kperras: @mikekazimer Why would you not use the Rocky Mountain ride 9 to make the mixed wheel size bike have the same geo as the regular instinct? I would think this would be a better test to see if the smaller rear wheel really makes a difference?? Changing the geometry of the bike probably made the mixed wheel sizes feel way better then they would given similar geo?? (I am a fan of both mixed and same sizes) Having the same BB drop as well as the same head angle would generate a more scientific test. I mean to be fair though the slacker head angle and lower BB probably only helped to make the bike corner better and feel more confident in the steeps.
  • + 1
 @mikekazimer: if you ain’t gettin tire buzz you ain’t holdin er wide enough. Seriously though ape index probably has more inference on getting the booty buzz here?
  • + 1
 What mean to say is that this test seems silly because if you’re sold enough on the benefits of a straight 29er to buy one in the first place I don’t think you’re likely going to slap a smaller wheel on the back thinking it will make you faster. I can see lot of people wanting to know if they can put a 29er front on a 27.5 bike and be a little faster without compromising the more agile feel of smaller wheels.
  • + 1
 @Laird: there is no ride9 on the BC Edition. The standard edition BB height would be too low due to the 140mm fox 34.
  • + 2
 @rideone62: If you don't want the compromised ride of a 29er you can always just go full 27.5. It's just as fast without the shit feeling of oversized wagon wheels.
  • + 1
 @kperras now that makes sense ahah!
  • + 61
 This is called Biggie-smalls. Clearly.
  • + 17
 @mikekazimer This is the only comment that matters
  • + 16
 Someone needs to come out with a bike called the Big Poppa.
  • + 1
 @mikekazimer: It would definitely be some atrocious fat bike that would make me want to run into traffic.
  • + 49
 Most people would benefit more from practicing than worrying about their wheel size
  • + 7
 Hell, Loic Bruni would probably benefit more from practice than wheel size.
  • + 31
 I just came here for the comments section. Don't fail me guys, bring the heat.
  • + 57
 Pick two wheel sizes and be a dick about them.
  • - 2
 @dingus: like a dog with two dicks?
  • - 11
flag Caddz (May 6, 2019 at 17:24) (Below Threshold)
 Rule 7:
29 and 27.5 don't mix
Like two dicks
And no bitch
Find yourself in serious shit
  • + 1
 El Greffe!!!!
  • + 27
 It's just a preference. What works best for the riders height, size, riding style, etc will lead to the fastest times. I think geometry is more important than wheel size honestly.
  • + 21
 That's what was really on test here, more than the wheel sizes. Repeating the test with geometry held constant would be more interesting. A bike with adjustable BB height and an Angleset would help. An imperfect test, but I appreciate Pinkbike's effort to start the conversation.
  • + 1
 @R-M-R: Agreed, in all of these geometry and wheel size discussions I consider everything to be a piece in the overall puzzle. If we were talking about drag racing, minor changes that impact things consistently over and over for timed runs in perfect conditions, that's one thing. But mountain biking has lots of variables that end up meaning more than wheel size in many cases. A tire choice, a good or bad line choice, etc. could impact you just as much as wheel size on a given day. The rider needs to determine what he/she is most comfortable on and can produce the best, consistent results on. I have both 29" and 27.5" bikes and love them both for their intended purposes.
  • + 1
 Spot on! My own experiments found exactly that. The lower BB was much appreciated at most times, but a little low occasionally leaving me thinking too much about hanging a pedal. Steeps were better, but lacked the 29er traction when I tried to drop the anchor. I prefer the 29 overall. Maybe I’ll try an offset bushing or two in the 29 version and get the results I’m after.
  • + 5
 @R-M-R: the real question is, what 's faster, a 27.5 with a 29er up front or a 29er with a 27.5 at the back...
  • + 3
 @adespotoskyli: Depends what Gee Ometry has to say about it.
  • + 2
 @adespotoskyli: Option C: None of the above!

One has a BB that's a little too high and the other is a little too low, and both have seat tube and head tube angles that are little too slack - assuming the original geometry was ideal.

If a rider's range of motion is restricted by a 29" rear wheel, then 27.5" is better - certainly safer - for that rider. If that's not the case, then I doubt there's much difference. The smaller wheel is stiffer, lighter, and has better suspension compliance for a given anti-squat, but rollover is better with the larger wheel.

I wouldn't be surprised if the difference is so small that it's almost impossible to separate from other variables - again, assuming the larger wheel doesn't restrict range of motion for a given rider.
  • + 0
 He pretty much proved that lower and slacker doesn’t really change much of anything against the clock
  • + 0
 @R-M-R: exactly, bollocks.

To many variables and such a fuss to be inconclusive at the end. there are other more significant issues to address on a bike like suspension performance that atm cannot be touched as it needs to many maths and engineering that won't hit to many arguments on the comments section. So let's argue about wheel size again as it always comes to a definite result.
  • + 0
 @adespotoskyli: wheel size can (and has been) isolated from the tests. If you always go behind the "too confusing paradigm" we will never find solutions. The real solution can be found from setting the goals (fe. fast bike or a bike that it's easier to land tricks), by testing and by logical analysis. When we use logic in the decision making of which solution from the multi-variable paradigm we choose, we can find solutions that serves the goals we set. The test
done here can be seen as well as, that by modifying geometey lower and slacker, the smaller wheeled rear can also keep up. Now if we modify the 29" 29" setup with slacker and lower setup and time it again, we find out which one is faster. I already know the answer ????
  • + 1
 @R-M-R: Get Saracen's Myst on the job. They have done exactly that!
  • + 16
 Tough crowd. Let's talk about the stuff that went well here- we got some cool content (that you didn't have to pay for and weren't forced to consume) discussing a view on a topic that is important in biking at the moment. Lots of people are probably seeing what the pros are doing and wondering if it is something they could do to improve their own experience and this could be a piece of information that helps in determining this. Not sure there is much "Kool Aid" around the mixed sizes- actually- kinda the opposite as those who race bikes and need to claw small but actual advantage have been experimenting and it is filtering into popular culture rather than popular culture driving this."kool Aid" was more 29ers, 27.5er's and not the bastard love child of the two IMO. Sure- lots of things that could have been done better as with everything else in life. But it took some work to put together, was meaningful, thought provoking (for me anyways...I can;t speak to others experience) and I enjoyed it. I always like these types of things- the trails side head to heads.
  • + 1
 Hell yea. Great comment sir. Optimistic, intelligent, and not a complaint. I would love more of this content from both PinkBike and its users!! Ride on man
  • + 13
 All this really tells me is that you got faster the more you practiced the lap. May have had nothing to do with wheel size, and more that you learned what lines to take and got faster as you became more comfortable with the trail.
  • + 3
 Completely agree. That is the clearest pattern in the results.
  • + 14
 It seems some have missed the point that it allows smaller riders to run 29inch front and get the benefits of it without getting their balls/butt crushed every times it gets steep.
  • + 2
 I think this is the only case with a clear winner.
  • + 14
 Surprised people aren’t mentioning that Motocross bikes have a larger front wheel.

www.motosport.com/blog/dirt-bike-tires-wheels-explained-sizes-pressure-treads-tools
  • + 2
 The only things similar about dirt bikes and MTBs are that they both have 2 wheels, handlebars, and a seat. The engine makes geometry a little less important compared to MTBs. There is a semblance of geometry wars in the dirt bike world, but nowhere even remotely close to what the MTB world has.
  • + 6
 Oh do they? This is the first I've heard of it!
  • + 4
 Or I don't know, chris porter and G16 and G1....this stuff has been proven long before Mike thought it was kinky enough to write about....
  • + 13
 The rear tires on dirt bikes are also typically twice as wide or more. Does that mean running a 2.5 on the front and a fat bike tire on the rear is a good idea too?
  • + 7
 @Almazing: How does engine make geometry not important? Check out motogp bikes. They adjust and tune geometry for different tracks. The change fork offset, swing arm pivot position, handle bar height and many other parameters
  • + 11
 @Almazing: It was raging back in the day, but to your point, as of late say after 2000ish, moto geometry has pretty much halted and has now focused more on suspension tune.

It is interesting though, MTB's have started getting very close to moto's Geo, both have 64 deg HTA's, low offset forks and stems are getting shorter.
  • + 14
 @Almazing: if that's true, then why does modern mountain bike geometry much more closely resemble dirt bikes than older mountain bikes? And why does someone like Aaron Gwin coming from a motocross background completely shred the competition when he hadn't ridden a downhill bike until his 20s?

Mountain bike development is just behind. There is more resemblance than you think. You even use similar techniques.
  • + 5
 and not to mention those burly ass motocross tires are the same amount of cash as the maxxis 29er tires I'm looking at for my mountain bike.
  • + 7
 @maxart: "The engine makes geometry a little less important compared to MTBs."

Reading is important. In any case, Moto GP is the highest form of motorcycle racing in the world. It would surprise me if the teams DIDN'T scrutinize every little millimeter. But motocross is vastly different from Moto GP isn't it? Like 2 different worlds. One would argue that motocross and MTB have more in common than motocross and Moto GP....

Geometry affects comfort when riding a mountain bike. Since you're more physically involved in mountain biking, you're want to look at geometry a little more closely. But on a dirtbike, you don't pedal. You're not pumping rollers. You twist the right grip to go fast and hold on for dear life.

The point I'm trying to get across is that normal non-professional people who shop for dirt bikes aren't looking at geometry the same way MTBers do. Because people are looking at the displacement of the engine for the class they're racing in. Or maybe they just want the biggest baddest dirtbike. Or the lightest dirtbike. Or maybe the most reliable engine. And dirt bikers have a lot more brand loyalty than MTBers. Someone who's been riding a Honda all his/her life is probably going to get another Honda. The moto world has settled for what works best already. There hasn't been any 'revolutionary' development in years in the dirtbike world.
  • + 3
 @byfan: This! Moto is a breeding ground for good MTBers. Not just Gwin, but look at Sam Hill and Greg Minnaar, both long time moto guys. It's good training when you can essentially ride a tough enduro / DH track for 20-30 minutes at a time and not have to stop or shuttle....aka riding a moto around a track or offroad through the woods.
  • + 4
 @mdackert: yeah, cause they're all single compound wire bead tires produced without weight as a consideration. The equivalent would be $25 heavy wire bead MTB tires. Of course a lightweight, folding bead triple compound tire is expensive.
  • + 3
 @byfan: some suspension companies even implement technology that has been in use for ages in the moto world. Manitou's latest forks and shocks (starting with the Mattoc) use technology common in the moto world (one of their main engineers used to work at Showa if I'm not mistaken). I expect Fox and RS to follow within a couple of years and market it as revolutionary and radically new technology.
  • - 1
 @Mac1987: some companies employ more marketing gurus than r&d staff, it makes money easier as making something to perform is much harder than convincing people that actually works, hence this type of 'tests'
  • + 2
 To be somewhat similar, you could put a 2.8 Minion on a 27.5 Rear with a 2.5 Minion on a 29er Front...
  • + 3
 @Almazing: All you need to decide when buying a dirt bike it 4 Stroke or rampaging fun 2 Stroke for the motor. The rest is incidental. MTB - well seeing as you are the motor - there is a little more that goes into the decision making process.

I must admit though - my midish travel 29er is a god send on technical trails compared to the older school XC Hardtail it replaced. Wish I had more elevation around where I live but I can always travel.

Now, how can I add a 27.5 rear wheel to my unicycle to try out a half breed wheel combo???
  • + 8
 Here are my experiences with self made "mullet / frankenbikes" which I've been running for around 3 years / 2 different bikes:

Pros:
- Much better resistance to going over the bars in steep downhill terrain. This in turn is a huge confidence booster and allows me to take a more centered 'attack' position on the bike in these conditions instead of hanging off the back.
- Better front wheel 'rollover' ability (common to all 29" wheeled bikes), both climbing and descending. Also more high speed stability in the front over rough stuff, a trait all 29ers tend to share due to the gyroscopic effect of the larger wheels.
- More front end 'pop' when hitting obstacles and sharp lips. The front wheel tends to deflect upwards more rather than getting hung up or plowing straight through. This can be good (makes launching off roots and rocks easier) or it can be bad (you can't steer when your front wheel is in the air). However, this encourages you to weight the front wheel more than before, actually improving grip and cornering.
- Related to the point above, jumping just feels more natural and controlled to me. The greater front wheel 'pop' encourages launching off practically everything while the landings feel more controlled as the larger front wheel gives a greater margin for error when landing front heavy.
- A higher front end (assuming you don't reduce the amount of front fork travel that much) means a higher BB which means fewer pedal strikes. (But this is also a negative).

Cons:
- Unless you reduce your fork travel by around 30 mm when you switch to a 29er front fork and wheel, the whole front end of the bike will be significantly higher. However, the higher stack height was fine for me as I was already using a bunch of spacers under my stem and a riser bar so I just got rid of those for a similar bar height.
- The higher front end also means your stand over height will increase which may be annoying if the bike already has a fairly high stand over height.
- This will also raise your bottom bracket by around 15 to 20 mm (which is also common in long travel full 29er bikes) which might be less than ideal because of the higher center of gravity. I never noticed this as an issue and, in fact liked the fewer pedal strikes as a result.
- It will also slacken the head angle by around 1.5 degrees which to me is a net benefit but does lead to a longer wheelbase and more wheel flop on tight uphill corners. A reduced offset fork may help with this a little or you can install a negative angle set if you don't like this.
- Finally and most importantly, it will also slacken your effective seat angle by around 1.5 degrees. You can somewhat compensate for this by slamming your seat all the way forward on the rails but to me this is the biggest downside on most bikes. For this reason, the bikes that are most ideal for this swap are ones with the steepest initial seat angle. As a result, I do find myself riding the nose of my seat on steep climbs more than I would like to.
- The larger front wheel and slacker head angle means you need to take the wide, outside line going into tight slow corners. This is typical of all slack 29ers though I believe. The one thing that may not be similar to a full 29er (I'm not sure on this) is that the 27.5" rear tire takes a significantly different line through the corner than the front. This makes riding North Shore 'skinnies' a lot more challenging than a full 27.5" wheeled bike as there often is not enough room to keep both wheels on the skinny when there is a turn unless you 'hop' the back wheel ( which I suck at).
- Another 'con' that will discourage many people from trying this is that it will almost certainly void your frame warranty. Over-forking and over-wheeling the front of 27.5" bike by this much puts a lot more stress on the head tube area of the frame so you wouldn't want to try this on a bike that is known to be weak in this area. That said, I'm a really heavy guy (riding weight with pack around 230lbs) and I've never had issues with this on either of my bikes in spite of the fact I rode hard enough to crack my shock link and break the damper shaft in my DB Inline shock (at different times) .

A guide to selecting a good bike to make into a 'mixer / frankenbike / mullet bike":
- Steep seat angle
- Not too slack a head angle or the ability to install a negative head angle set if you don't like super (DH like) slack head angles on bikes. (I really don't mind the current 63.5 head angle on my Patrol with the 29er fork but many might not like it).
- A low BB and stand over height in stock configuration
- A strong head tube area; carbon bikes may be the winner here as I would be more concerned about welds breaking after some time on an aluminum bike due to the extra stress over time.
- A bike designed around a 170mm or even 180mm 27.5" fork would also be ideal for the strength and geometry reasons already listed above. I think the new 2018 SBG Transition Patrol and probably 27.5" YT Capra would be ideal bikes for this type of conversion, although the Transition Patrol at least would probably require a reverse angle set or you would end up with a 63 or even 62.5 degree head angle.

The bottom line for me is that a 29 front, 27.5 inch rear bike is best for the Pacific Northwest steep and technical up and down trails and bike park riding. Obviously this will not be for everyone, and probably would not be great for cross country but for me its perfect.
  • - 3
 All of these pros can be done with out a mixed wheel size, only 27.5 or 29er, what makes me wonder when and if the front 29er does roll over better, what happens to the rear that follows? Surely won't go as easy as the front, that sounds like unbalaned situation to me...
  • + 1
 Correct me if I'm wrong (with some maths please!), but I think the 1.5deg HA reduction stated in the article is wrong.
HA change is approximately = asin(19/1213) = 0.9degrees (where 19mm is reduction in wheel radius, and 1213 is wheelbase).
  • + 2
 @adespotoskyli While the rear 27.5" wheel may not roll over things as well as the 29er front, the force vector from the rear wheel getting hung up is far different than the front. In other words a 27.5" rear wheel may possibly be a little rougher than a 29" but it will not send you over the bars if it gets a little hung up.

@rmjowett: Keep in mind the increase in axle to crown height for a 29er fork as well. As I said in my comment, the total height change at the front wheel is around 30mm.
  • + 0
 @you are wrong, “27.5” wheels actually measure closer to 26.9”. I cant remember where the 27.5 number came from but its (maybe some marketing campaign) but its a load of shit. Also for this reason I think there will be a new wheelsize in between 27 & 29”. The mixed size bikes look interesting but they highlight how much bigger the 29” wheels are & with people liking bigger wheels but not all able to get on with them
  • + 1
 @Xorrox: Ah, fair enough.

In this article they only changed rear wheel, so I think it's 0.9deg.

By the way, great comments - very useful to help with understanding this concept.

Worth checking your BB drop. Since the chainstay is roughly 1/3rd of the wheelbase, a 30mm increase at the front would be a 10mm BB increase.
  • + 1
 @zyoungson: Check for actual wheel dimensions here:
flowmountainbike.com/features/nerd-alert-wheel-size-by-the-numbers

asin(17.5/1213) = 0.8deg, so even less effect than my first calculation!
  • + 1
 @Xorrox: issue here is being unbalanced, if the rear that takes far more beating due to weight distribution, what's the point making it even harsher feeling with a smaller wheel, nothing to do with sending you over the bars
  • + 2
 @adespotoskyli: Re: over the bars: When a wheel hangs up and your weight shifts forward, the load on the front wheel increases, while the load on the rear decreases. A front wheel can fully stall against an object, while a rear cannot (unless the axle height is less than the object, but you're already doomed in that situation).

It's true the rear wheel carries more weight and rolling efficiency will benefit from a large rear wheel, but that's a separate issue from the question of whether a bike will send you over the front.

For riders who frequently hit very steep moves, a large rear wheel may be too large to move as far back as they want. These riders may need the smaller rear wheel, regardless of any other drawbacks. As an example, I don't think I've ever contacted the rear wheel on a 26" or 27.5" bike, but I contacted my 29" rear wheel twice on a ride with rock rolls that aren't the steepest I've ridden. I'm worried about what this means for really steep terrain.
  • + 1
 @rmjowett: I believe you are correct. I don’t have the spread sheet I did all the calculations on any more but the very roughly 1/3 of 30mm bb rise (~10mm) sounds about right.
  • + 2
 Bravo on the write up.
  • + 1
 Thank you for posting your real-world experience. 99% of the negative comments are sheep that can't afford to own both setups, and too naive to put in their own time to try something new. Coming from the motocross world, and hearing some positive overall reviews from people actually trying "mixers," I'm curious to try a 29er front wheel on my trail bike. Ride on man
  • + 1
 @Mr-Pistol-Peter: all pf the pros and cons in the arguments can be achieved with geometry alterations as simple as a longer fork or an angle set, nothing espesially that is a mixed wheel application
  • + 1
 @R-M-R: the quite bigger bb drop on 29ers, I believe can counter act what you say, as the lower centre of mass of a rider is quite more significant than the lower 27.5 wheel to help you not to otb. Honestly, I thing a well designed bike can work, but a mixed is a big miss and hit as most don't agree on the advantages as such but solely on estimations
  • + 1
 @adespotoskyli: BB drop does not matter, only the location of the centre of mass. The location of the CM is not changed by the wheel size.

If the entire mass was located at the BB and the system was rigid, then yes, BB drop would matter, but neither of these things are the case.
  • + 1
 @R-M-R: it does, when the bb is lower than the centre of the axles you push through obstacles easier, an exaggeration is when pushing a sledge, the closer to the ground you grab it slides easier the higher you grip the more bucking up front or lifts the rear. When smashing through rock gardens higher bb, especially higher than the wheels axles centre the more likely to buck all the time. Also when you push through the pedals CM isn't exactly located at saddle height. Actually it floats around accordingly
  • + 1
 @adespotoskyli: That is a myth. If you draw the free-body diagrams, there's no centre of mass at the pedals for the "push" to come from. Also, the greater BB drop of a 29er does not equate to a lower BB height; two separate issues.
  • + 1
 @R-M-R: thats why first 29ers sucked, because they chucked 29 inch wheels on 26 inch frames raising the bb and CM. I'm always talking about bb drop as it doesn't change in regards to sag or tire size, bb drop makes much deference than actual bb height,
  • + 1
 @adespotoskyli: I'm well aware of these things. Assuming we're comparing bikes with equivalent BB height, the position of the BB relative to the axles does not affect rolling efficiency or whether a bike hangs up on obstacles. There is no inflection point in any graph when the BB moves above or below the BB.

That said, I recognize a bike with larger wheels must have more BB drop than a bike with smaller wheels if it is to have the same BB height. The bike with more drop will have lower rolling resistance and is less prone to hanging up if everything else is equal, but that's because of the wheel size, not because of the drop.

I'll say it again: for a given BB height, placing the BB below the hubs has no effect on on roll-over properties, stability, etc. due to being below the hubs.
  • + 1
 @R-M-R: actually it does, for the same reason you load the outside pedal when cornering that's because it sits well below the centre of the hubs, try cornering with level pedals, or pegs,
  • + 1
 @adespotoskyli: Again, I disagree. The rider applies little fore/aft force through the pedals; most of that comes via the handlebar. If you were standing on ice and someone pushed your feet, imagine how little ability you have to resist that motion. If someone pushed your hands, however, you can resist more effectively. Again, draw your free-body diagram: if the feet applied a large amount of fore/aft force, there would be a large rotational acceleration around the centre of mass. Your hands are nearly in line with the centre of mass, which is why they contribute the majority of the fore/aft force.
  • + 2
 @adespotoskyli: They can also be achieved with front wheel altercations. You know... like what this article is about...
  • + 1
 @Mr-Pistol-Peter: yes, it's easier, cheaper and a whole lot better isn't it??? Ffs
  • + 7
 In the past we were all running 26" wheels that fit all of us, as there is such a thing as frame size and now only small people are supposed to use 27.5" and only at the back. I'm disguissed how stupid bike industry think we are and I'm sick of all this wheel size topic. MTB is going in a very wrong direction.
  • + 6
 Couldn't agree more. When they introduced 27,5'', people were bitching about them, not to mention 29''. Today, it's hard to find someone who still stands by the 26''. I don't know if it's the hype, or the absolute necessity to fit in, that everyone feels.
I just can't get over how ugly wagon wheels look on a bike. I mean, I run 26/24'' and plan to switch to 24'' completely, so I'm definitely not the norm. But if I like how it looks, I have fun riding it, and don't chase every millisecond on a trail, I couldn't care less about all the new sizes.
If people like them and enjoy riding them, I'm glad. But I hope there will always be 26/24'' option for dinosaurs like me. Seems like kid's sizes will save me, now that they make Minions in 24'' Big Grin .
  • + 4
 @adam102, out of curiosity, since you say you're switching to 24", how tall are you?
  • + 3
 @adam102: how do you know when someone cares about wheel sizes? They'll tell you they don't care then go to great lengths to defend how the wheels on their current bike is the best...
  • + 1
 @mikekazimer: Whoops, I didn't check my Dashboard for a few days, sorry! I'm 6'2'', or 188 cm. I ride a 12,5'' hardatil similar to Evil Imperial.

@lennskii At the same time I care and don't care about wheel sizes. I don't care about what majority of people ride, but I care whether I still have the option to go my preferred way. My rant probably wasn't worded very well.
  • + 6
 What the Pros ride could not be more irrelevant in the "real" world! I heard Greg Minnaar talking in a recent vid about how the faster setup felt bad. I know that is what I want when I'm out shredding ... a bike that feels like shit!
I know why the pros do it but with most riders it is all about fun.
  • + 8
 Could there be an advantage with sprinting in the beginning of a race, or any pedaling section? Your test was all about rolling.
  • + 3
 smaller wheel can put down more torque = quicker acceleration
  • + 1
 Not a big difference. Pretty much all XC bikes have been 29" for a long time, I'd consider that a pretty good testimony on how well 29ers pedal.
  • + 4
 My 10 year old's (now an enduro and whistler rippin 17 year old) first bike was an aluminum giant hard tail with 24" wheels. He dominated with that bike, but had issues rolling over rocks on our abbreviated outings. I ended up installing an old Rockshox Judy with a 26" front wheel. He immediately progressed from dominating to SLAYING. He had to be careful not to pedal into his front tire on technical climbs, but kept up incredibly well on descents. That bike only weighed 20lbs and looked dope AF.
  • + 4
 Would have been nice to also try transplanting the 29er fork/wheel from the Instinct onto the 27.5 Altitude for that test. I know that's more time consuming, BUT you get the shorter chainstay that way like Maes is doing it on the Force.

For sure timed testing like this is always going to be super close. Seems likes that's true every time someone does timed, multiple set course laps. BUT races are super close...?

For the rest of us who are not racing it's just gonna be feel and perception. One thing about throwing a 29er front end on a 27.5 is you get that "new bike feel" for a lot less money!!! Smile
  • + 4
 Totally agree regarding geo. Being important. Putting a 27 on the back of an old but loved 29er hardtail with conservative geo has livened it up and made it loads of fun. I was thinking about anglesets and all-sorts to brings it up to date but the mullet has been a total blast.
That doesn't I'm saying a contemporary Enduro / DH bike that has sweet geo needs it though.


The cool thing about this in my opinion is that it's not industry marketing specific telling or forcing us to buy. If you have a spare 27 stick in on and try it out. Even if you dont it isn't that expensive to buy a cheap 27 to try it out for a few months.
  • + 8
 think warm thoughts my antarctic brother
  • + 4
 What has me intrigued here is that there may not be a time penalty for the setup that may be more fun. I’d love to try the 27 rear just to see if I like it more for cornering and more playful feel on jumps. I would think with the less mass and size, there would be less centrifugal force to fight to get the bike to lean or get a bit sideways in the air. For a rider like Bruni, I think he can get lower on the turns without the butt hitting the tire v 29er rear, which aids in his cornering style, so maybe even faster. Few of us can rail corners like him, so it may not be faster for all of us, but having no time penalty for the setup may just prove to be more fun.
  • + 2
 Great analysis! I’ve been experimenting with this for years. And have concluded the 27 rear wheel is just more fun! And the 29 front wheel steering is just more stable with better traction. The way you can get slideways with this setup is what’s missing from 29 all around. Only issue is the slack sta you get if the bike isn’t designed for it.
  • + 1
 That's wht I want to try a 24" on the rear of my 26" bike, seems like more fun.
  • + 7
 Dude, Plus size tires are revelations for me on a HT.
  • + 3
 Haven’t you heard Plus is dead?
  • + 7
 Plus tires fading away? I didn't even get to them yet.
  • + 3
 This test should be done with a bike that can accommodate different wheel sizes on the rear without changing it’s geometry.

I only know of Liteville doing that on their latest 301 mk15. Liteville has been doing this for many years already...
  • + 3
 I ride a mix size wheel bike for the last year. You need to do it on a 27.5 bike with short chain stays. Change the forks. I run 44mm rake/off set. In my testing. I am able to change lines easily and ride lines I couldn't before. Rolling speed is faster than 27.5 bike. But the best thing is how big the smile is on my face now in the corners and over the rough ground it is so much fun to play on.
  • + 5
 Going from 27.5 to 29 on the same DH trails the 29 tire will buzz my heinie quite easily so I can understand going 27 in the back.
  • + 6
 ive been running mullet for a few years and love it. each person is gonna be different tho. ride what makes you happy
  • + 2
 Me too it’s just more fun
  • + 2
 Mike's runs are impressively consistent. Still, in this test like every other wheel size shootout, the difference in times between replicate runs is substantially greater than the difference between the test groups. Fun to watch, but for entertainment purposes only. 4:46 difference between runs on 29, 3:56 difference between the mixed runs and differences between the test groups were virtually nothing to 0.9 sec.

Looks like wheel size still doesn't matter much.

@mikekazimer any thoughts on how you aced 4 seconds off your initial times for the last 3 runs?
  • + 2
 I think the increase in speed comes down to getting to used to the track conditions. It was a little dry and marbly in sections, but by the end I'd gotten a good feel for the level of traction.
  • + 13
 @mikekazimer: Meanwhile the guys at Vital do a 1 run DH bike test and declare a winner authoritatively. Apparently the concept of variance and sample size is beyond them.
  • + 2
 can a bike be faster than other bikes? Well, can a bike be by itself? Kant would say no, so, how can a bike be faster?. It's obvious now that we need to talk about the bike-rider couple. So, can a bike-rider be faster than other of it's own nature? Yes indeed, but how?

What is a bike? It's a group of individual components joint together in a certain way that allow it to circulate through a trail. To get the performance of a bike-rider, we need to consider the performance of each of the individual components and the rider's also.

So, with that in mind, can a single component really be that important to the bike's performance? No, it's only as relevant as the others parts. We may build a relevancy pyramid with the components, but, i don't think a single component (the rear wheel in this case) can make a significant improvement.

It is the whole thing, the bike (group of parts) and the rider (group of skills) that make a difference. As Richard Cunynghame said, while watching Aaron Gwin rippin Val di Sole 2011, it's death by a thousand paper cuts.
  • + 5
 29 is fast but no fun 27.5. Fast and fun only a bit slower then 29 I am no pro so I think fun is more important
  • + 3
 In the early 2000’s I was running a 26” front, 24” rear on a Pipeline with a Manitou Sherman Slider form. Now that was a mullet bike. What’s old is new again. Get off my lawn!
  • + 6
 I think I'll just ride my bike and not worry about it
  • + 4
 That's the best tactic.
  • + 2
 I've been wanting a mullet bike for 2 years now. So, I'm well over the debate.
Now I just want a comprehensive guide on how to build one. It's a bit tricky to decide on a 27.5" frame or 29" frame. But this article helps.
I had been thinking of getting Jamis Hardline and putting a 29" wheel on it.
  • + 2
 I don’t know you guys, but I think that wheel size is almost all about the riders height. If you are 6”4 I reckon the best wheel size is 29”, if you 5”4 650b, and if you are somewhere in between maybe mullet works out
  • + 5
 As far as what to call it, well Foes has been doing for a while now as the Mixer.
  • + 2
 I love testing stuff like this and think it does have relevance. However we are talking about ultimate pace , unless you are a Bruni , Gwinn, Hart etc your slightly faster mate on their ten year old 26er will still smoke you. You will be able to get a little bit closer to their back wheel but that is all. Definitely not speaking from personal experience here.
  • + 2
 I've been running mixed wheels for almost two years now (Following MB) and I'm super stoked on the set up. I am vertically challenged so it works for me and I no longer have tire buzz on all my shorts. It also handles better in tighter corners compared to my Following 1st Gen. I do lose a bit of speed in flat out rough stuff as well as having to pedal a little more on the mixed wheels.
  • + 2
 2 years in on a Foes Mixer. It's just fun to rip around on. Very comfortable and enjoyable to ride. Defiantly is an advantage over a 29er when setting up for back to back sharp corners, switchbacks, and quick accelerations. I don't know if a "speed" advantage exists but it sure is fun and handles GREAT.
  • + 2
 Coming from a 29+ bike I am more a 27.5+/29 mullet advocate. The biggest issue I had with the plus bike was the vague handling with the frontend and the 27.5+ bikes I tested were a bit meh with a smaller wheelsize and less rollover ability than a pure 29. A 27.5+/29 mullet setup gives the traction of the plus size, the rollover ability of a 29 without that vague feeling and the weight penalty of a full blown 29+.

I'm not a pro, just a guy enjoying his bike in the mountains who don't do timed runs.
  • + 2
 Rollerover of larger front wheel and ability to pivot rear on tight tunrs arent the only significant theoretical advantages - also get longer contact patch with translates to better lateral grip on the front. And on the rear one can put down more torque for faster acceleration on the rear with a smaller wheel.
  • + 2
 A somewhat objective, quantifiable test @ Pink Bike, what is the world coming to? Thank you! Too bad more of the reviews and testing of bikes and equipment here isn't scrutinized in this fashion. Like maybe, occasionally, just for the shear novelty of it, instead of verbatim regurgitating a bike brands latest and greatest version as improved, test it against the previous generation against the watch.
  • + 1
 I have tried it on my Mondraker Crafty m.pinkbike.com/photo/15728791 and it worked OK but I can't say that it was a game changer for me. The biggest difference was the change in geometry (slacker HA) rather than anything else (cornering etc). Would I try it in my Sentinel? Not really unless I would like to run a 2.6 or 2.8 rear tire.
  • + 1
 I’m sorry mike but you are not a pro racer,maybe it doesn’t affect us all or we could maybe not feel the difference,some want a sportier feel others don’t ,but what I want to say is for you it doesn’t make you Much faster ,it could also make you feel less comfortable,but it might make a difference in a pro racer or it might not ,but it does makes people wondering about all the rest what affects the handling of it ,there are so many variables like tires with,so ......,let game continue
  • + 5
 Wrong. Everyone knows 26" is best.
  • + 1
 reminds me of when we ran 26" F and 24" rear on our DH or FR bikes... It worked, granted our bikes were not as advanced with their geo or suspension as now. Now, if anything it matters to the racers perhaps that are able to use the changes to their advantage. I could care less. Will it influence my next buy, nope! These wheel debates are getting so old, like when we were discussing a 650b (27.5") front and a 26" rear in like 2010/2011 ish. Time to go ride!
  • + 1
 notagood test @mikekazimer

If you ride each lap at the same pace, why would you expect any difference in times?
Should have done a no pedal-coast only run to eliminate differences in effort...
and then runs at max effort to see if there's any real handling advantage while 'on the edge'
can you try this again?
  • + 1
 On long travel and DH rigs the rear wheel takes much more of a beating than the front. A smaller, more durable wheel out back is more practical. Pros get new wheels all the time. I don't. Heavy rim, full DH casing, and inserts on the rear for me, on a 275. On a 29 that's going to be pretty porky. The rollover of the 29 up front makes the most sense too. It's where the benefits of a bigger hoop are most noticed. Short travel bike 29 both ends, burly bikes with 29 are pushing too much wheel. On my next AM or DH bike I'd buy a 29/275, but not a 29/29.
  • + 1
 @mikekazimer Hey man, can you put in the Pipeline's lower cup (same frame- used for 27.5 plus tires) and bump the travel up to 170mm (maybe?) and try this again with 27.5 wheels? That bike is super configurable (especially with ride). I think it would be meaningful to gather the additional 27.5 data. It would certainly generate clicks. Not having the 27.5 data is a big hole for a lot of people. This bike makes it relatively easy to do these things with.

Fwiw this bike is #2 in the EWS overall. Team Rocky has done well.
  • + 1
 @mikekazimer: There's really no reason to title this "Are 29/27.5" Mullet Bikes Faster Than 29ers?" and present a conclusion of your results, without conducting a much higher quality experiment.

To have a reasonably fair test you need to remove as many variables as possible, with a 1.5 degree change in head angle and half an inch change in bottom bracket, these factors are likely swaying the outcome significantly.

Regarding your test procedure ie. number of runs and time on bike; There is no way that swapping back and forth briefly, without spending days in a clearly settled setup, that you will achieve a thoroughly developed opinion. vehicle operators need time to absorb the more nuanced variable qualities of each setup, and exploit their potential. you also need a much larger test sample size, with a variety of operators.

Surely there are other fine tuning setup attributes that should be also addressed to maximize performance; stem arrangement, handlebar roll, seat position, suspension settings, brake rotor size, tire pressure.

I thought this was the biggest mtb media business in the world, i would presume your orginization could muster a quality experiment, with a mechanic changing headset cups, spending a full day or 3, etc... this "experiment" hardly passes the quality of climate-change-deniers "science".

My bike has and is optimized for 29 front 27.5 rear wheels. i've done much of this research personally from feeling, timing my test tracks, and anazyzing data changes to parts and the dynamic geometry and position of the bike. there's now way you can take the extent of setup changes on in a day or so to reach a good conclusion.

Please try to set a good example for science and reasoning in the future. Good luck.
  • + 1
 correct me if I am wrong but the only reason why GT has the mixed wheel size is because they dont have a 29er enduro bike. My guess is martin wanted a faster rolling front tire so he put that on and saw the benefit. if he had a 29er enduro he would have just ridden that and would have gotten the same result.
  • + 1
 @mikekazimer

www.pinkbike.com/news/foes-mixer-trail-review-2016.html super oldskool XC geometry but yah

www.mtb-news.de/news/2013/05/11/liteville-scaled-sizing-ganz-eigene-empfehlung-zum-thema-laufraddurchmesser

oh yeah and I was running a 29er front wheel 26 rear on my demo 8ii in 2013, I took the fork off my high pivot idler driven 29er DH bike from earlier that year. Obviously.
  • + 1
 @mikekazimer Would love to see future tests like this but with more data. eg. What parts of the trail was (insert part name/bike name) faster than (insert part name/bike name). In the motocross world they use a LITPro GPS device, it would be cool to see it put to use testing bike products.
  • + 1
 Litpro is a cool device - I used one a couple of seasons ago while doing some testing on the Trek 29er. www.pinkbike.com/news/riding-the-trek-session-29-2017.html. The only downside is that it doesn't do that well in heavily wooded areas, but I bet we could find a section in the Whistler Bike Park that would work. Being able to see where time was made or lost is really interesting to see.
  • + 2
 They are faster but the mullet needs more than a wheel swap. We have a thread for these mixed wheeled bikes and modifications that makes them faster: m.pinkbike.com/forum/listcomments/?threadid=203239
  • + 1
 Unless you’re into spandex, most bike trends in the last 10 years have been driven and proven by the World Cup DH Circuit. Geometry, axel width, wheel size, head tube angle, handle bar width, etc. There’s a reason why plus sized tires aren’t on DH bikes and are not what everyone said they would be. I think the mullet concept is cool. Will give 27.5 bike owners a way to improve their older bike. Trek did this a long time ago on a single speed mtb. It was called a 6 9er it won a championship. @mikekasimer it would have been cool to see the times compared to a full 27.5”. Time will tell
  • + 1
 Check out the Foes Mixer... Brent has long been innovating off road technology while others follow. Personally, after trying out the mixed wheel format on my Niner Jet RDO 2 years ago, I've yet to go back to a 29" rear wheel. I guess geometry is part of it on my rig (slacker head angle) that makes it handle more like a Trail bike rather than an XC bike. Maybe not faster, but more fun!
  • + 1
 I think for the top pros were every small difference can help get results but for the average Joe it will not make much of a difference. How ever if it feels good ride it. Don't fancy carrying two different size tubes tho????
  • + 3
 A 27.5” tube will fit a 29er without any issues, but the mixed wheel setup does mean that you can’t swap a front tire to the rear when that one wears out.
  • + 2
 @Naturel: link? I don’t follow
  • + 1
 @mikekazimer: That's been my main complaint about mixers. Sounds trivial, but I would be run my front tire a lot longer, rather than my current practice of moving it to the rear at the first sign of significant wear. Running half-dead front tires would hurt my speed more than the "optimal" wheel size would help.
  • + 1
 I've used 29er tubes on 29, 27.5 and 27.5+ bikes before without any issue. Even in some cases to ride a few days until I got a chance to get a new tire.
  • + 1
 @Naturel: thanks. That is slick!
  • + 1
 Dropping the BB 12mm is significant. I think for most setups I'd rather put a 29 on a 27.5 bike rather than 27.5 on a 29 bike for the geo changes. However, it is definitely is easier to just put a 27.5 wheel on a 29er so you don't need a new fork.
  • + 1
 Next big time "2975"? The first brands (Alutech for example) are showing complete bikes with this mix but only models which are usually equipped with 27.5 wheels and then get a 29er front wheel.

Maybe with an angle set the added stack height and shortened reach wouldnt be a problem! I think not so tall riders just take the next bigger frame size to convert this and then have nearly the same geometry then with the normal 27.5 bike only with the higher stack and so it will work better in really steep sections.
  • + 1
 @mikekazimer both the tazer and the decoy are 29"/27.5.

I'd love a test of those two bikes against each other despite it being ebikes.

To flatter you a bit and too be very transparent, all the ebikes websites I can find do tests that are too simple and the writing is poor. You do better words and content.

Even if you won't do a complete back to back review I would still love to understand why they chose to go with 29"/27.5" on the two eMTBs that are mostly meant for downhill. It seems in line with what you are writing about here.
  • + 4
 For steep places it’s a great idea. Ya have to be pretty cold not to buzz your balls on a 29er on Squamish slabs.
  • + 1
 And have the big wheel on the front is great for the big drops, as well as having more grip in the corners. My bike feels like my snowboard in the turns now. So much fun.. As a shorter ride I can hang of the back and not have 29 wheel hit me.
  • + 1
 The problem with this test is that the rear triangle on the bike was designed for a 29er wheel. This means the chain stays are to long for the 27.5 wheel. Change the rear triangle with the wheel or put a 29er fork on a 27.5 frame and rear triangle.
  • + 1
 For all those out there who have commented without trying one, go try one. I will say that it's best to to find a bike that has the right geometry to for this situation and is designed for it but I've met a few guys who have mixed their SC Hightower or Mach 6's and love it. I'm fortunate enough to have Brent Foes about an hour from my house and after a brief conversation with him you can tell he thought it out and designed the bike around the idea. And it works. My Mixer Enduro came in at just over 30lbs and is almost all aluminum (even the wheels). Friends have tried it and loved it but will still stick with their name brands and designs which is fine; they are good bikes. This 29/27.5 just makes sense. As for the pros I think you'll see more guys jumping on board. It's really all about the 29 front. The rear is just a compromise to get it to turn quicker, spin up faster, and add clearance. I love mine and won't buy or build another non-mixed bike.
  • + 3
 So cool to see such a factual test! Wonder if using flip chips / offsetbushings to mitigate geometry changes between 27.5 and 29 can change the outcome or not.
  • + 1
 Using 26inch wheels and im sure wheelsize is not what makes me so slow. The wheelsize thing is biggest overhyped bullshit in bike history. Especialy in DH racing. Was watching Hill Peat and Blinkykid "oldage" downhill racing, and i dont think, they were slow, and dont think, they think they are slow. Tbh it was best years of downhill racing for me, most enjoyable. They were on same wheels, and they fight man against man, not wheels against wheels. Sadly, as F1, DH racing will became boring and overtech one day
  • + 6
 Ride a good 29er then go back to 26 and tell us it’s not squirrelly as hell!
  • + 1
 Ya totally and we should go back to telegraph and horse an buggy.
  • + 1
 I hate progression too.

Companies want their paid riders to be on the top of the box. Compnaies also don't want to waste money on gimmicks or unnecessary R&D. If 26in wheels were faster, or as fast riders would would be on those. How about some cantilever brakes or short wheelbases too?
  • + 0
 Advancement is stupid!

/s

F1 is at the forefront of automotive development. It is literally prototype racing. Many things engineered for the purpose of winning races in F1 has made it to consumer vehicles. It's called the trickle down effect. This is good for everyone.

DH racing is not prototype racing. You can buy a Session, and go try to qualify for a regional or local race. Now there maybe things that teams are using that are prototypes on the bikes... Like maybe a new for damper or shock. But the bikes themselves are readily available to the public. And DH racers in 29ers and 27.5s today are pushing the envelope for faster and faster times. A 26er from 10 years ago won't hold a candle to what today's bikes can do.

Are you saying that the best years of DH racing for you were when you were slower and rode a really sketchy bike that can buck you off at any second causing you to land on your head and have a concussion? It's certainly exciting waiting for a train wreck to happen.

Progression is good. I believe that the MTB world is going through a renaissance right now, so to speak. Eventually, companies will settle on what works and what doesn't. Which is why 26ers mostly found on DJ bikes nowadays. Where they belong.
  • + 8
 @Purpledragonslayer: When you say go back to 29er, are you going back to one with dated geo?

You won't likely see another 29er under my bum for the same reason you don't see them at the dirt jumps, skate parks, on trials bikes, or winning at pump tracks. Once you get away from pure racerbois mentality, you'll realize that virtually every non rolling speed tradeoff is a lose on bigger wheels. The industry won't sell you on the negatives.
  • + 2
 @AllMountin: lol "once you stop mountain biking you will see modern mountain bimes suck". Cool story bro
  • + 1
 @Purpledragonslayer: Did just that last weekend. 29er Jeffsy, 26er C'Dale Rize. Both 140mm travel.

Yes, 29er is more capable on difficult/challenging terrain.
[PS - riding also a carbon 26 w/170mm coil sprung and the only complaint would be geometry being a bit "short", but after some pedal strokes, you easily adapt and the fun factor kicks-in]

Yes old Rize is still fun to ride, and it doesn't give that mute feeling on less difficult/challenging terrain.
Actually I prefer to ride this bike on double/single tracks that are rolling and easy - Go figure!
Rize was set years ago, as a 69er, really enjoyed, but it had only 100mm travel!

In conclusion:
It's possible to maintain speed with Big wheels (even if you're tired!) and they feel very secure/bags of confidence, problem is that it mutes a lot the terrain, and if you're not tuned to win KOMs, ou Races, I would go for the bike that it's possible to have fun - If that corresponds to 29er... so be it!
  • + 1
 @clink83: I see why you took it that way, but I wasn't suggesting that you should take your trail bike to the skatepark. I'm pointing out that those dynamic qualities that make smaller hoops excel there, also apply on any decent trail. You're paying the price for stability and ease of rollover with a lower quality of pump and marginally weaker handling dynamics. 29ers win on the stopwatch because they're 'good enough' in those parts of the trail and faster over rough and pedally bits. Very few tracks offer enough pump and handling to offset the time gains of 29ers in other areas.
  • + 1
 @AllMountin: na I like to go fast and compete with myself and others.

And as far as loss of handing the parts of handling..the parts I'm losing I don't really care for anyway.

I never liked twitchy ass 26er handling.
Having to work harder to go slower isn't fun to me.
  • + 1
 @AllMountin: and I really don't like that a pro gravel racer is cyclocrossing his way to all the kom of my local trails.

It's my phucking mission to take those kom back for MTBERS who actually ride the terrain.
  • + 1
 /quote

Is the 29” / 27.5” combo the future, or is it just another trend, a blip on the mountain bike radar that's going to fade away like Plus tires? It's hard to say, but I do think the concept has merit, especially for shorter riders, or riders in search of different handling characteristics. 27.5” wheels aren't dead, but their days of getting to enjoy the view from the front could be numbered.

quote/

Today in EWS -> 27.5 is alive and kicking. Dailly, Maes and Eddie in front ... get your facts straigt Wink
  • + 3
 With the ride9 flip chip, it seems like this was a missed opportunity to isolate the effects of wheel size from the geometry change caused by the switch to the smaller tire.
  • + 2
 Completely agree. There are many bikes that have a wheel size flip chip that could have been used.
  • + 1
 @mikekazimer I have been considering trying a 29er reduced offset fork in my 650b Stumpy for a couple reasons. Firstly I feel like if I’m gonna “fork out” for a new fork, I should future proof and get a 29’er fork, also my 2017 stumpy could stand to be a little slacker and I have been curious to try a 29’er for the roll over. My next bike will likely be a 29’er build project and the fork could be used there. Any reason to not try this... would be curious if anyone thinks that would just make the stumpy a monstrosity. Lol
  • + 1
 Why is rollover more important for the front wheel than the back? The front is the first one to hit an obstacle but also typically has less weight on it than the rear, therefore it seems like rollover on the rear should be just as important.

Don't get me wrong i'm tempted to try this on my capra 29 set to the high position but I don't have a 650b wheel right now. Any benefits to a plus wheel on the rear?
  • + 1
 There isn't less weight on the front wheel, if you aren't climbing. It's nearly the same.

But, as you are "pushing" the front wheel, and "pulling" the rear wheel, the front wheel will be hit harder than the rear wheel.

I don't know if you'll benefit for a plus wheel at the rear, but you'll suffer less from the cons of a "plus" format in the rear than in the back.
  • + 1
 I think the profile on rear tyres needs to decrease. A low profile tyre on a 29er rim would be close to the same rolling diameter as a 'normal' tyre profile on a 27.5 rims. Low profile rear tyres would be less prone to burping and pinch flats, and lower pressure could be run give better traction.
  • + 1
 To get a statistically significant result (defined in this case as one where you're at least 95% sure what you're seeing is not down to chance) you'd need to see an average time difference of at least 5 seconds between each wheel size (based on a simple 2-sample t test calc). You'd never expect wheel size to make that much difference, so this test is 'underpowered'.

If you want to be 95% confident an observed difference as small as 1 second is real, then you'd need to do more like 25 runs on each wheel size. Realistically you'd need to use multiple bikes and riders, or do it over a week.

It does make me wonder how the pros do timed testing of components. As the benefit from each change gets smaller, the number of runs you need to reliably spot an improvement becomes gigantic.
  • + 1
 I rode mixed on a Mutz, and s couple other bikes including a Smash, it’s not bad, some bikes work better (Mutz), on others it sucks ( Smash). It’s just a thing to try, it’s not gonna set your world on fire.

Personally, when run more travel I prefer a shorter wheel because the bigger wheels jack up the bike height.
  • + 1
 I have an OLD bike that benefited from this greatly. 2007 Titus Racer-X. Fox float 100 fork. 27.5 wheel fits great. This and a short stem and wider bars transformed an old bike into a really nice XC bike for my son. The modern version is more nuanced, but as a fix for a dangerously steep head angle, the mullet worked great.
  • + 1
 For test to really be about wheelsize, the frame geo would need to remain consistent. In this case, geometry change might be influencing as much or more than wheelsize. Still fun to think about though. As rear wheels were being swapped, this also seems like an opportunity to do the test as a blind, and have the rider not look at rear wheel before each run. Going 100% effort might also create more obvious discrepancies between wheel size.
  • + 3
 My question is:what did you do between lap 3 and 4? Opened the handbrake? Found some french lines? Or just had a beer?
  • + 1
 what you have done here is taken a 29er and lowered it's bb. Whereas all the racers have takes a 650b and raised its bb.
Or are the two rocky Mountains the very same frame with different paint?
  • + 2
 Rocky has 3 bike permutations with one bike. A ride9 chip adjust the HTA, STA, shock profession and BB height. The pipeline is their 27.5+ permutation and also utilizes a lower headset cup.

The Instinct is stock 140/140. The BC Edition is 155/160. All use the same frame. The BC Edition is long shocked and in the steepest ride9 position (not adjustable for that version). Due to this the BB is somewhat high thus allowing for a smaller wheel outback without compromising the BB height.
  • + 1
 the discovery of hot water! here in the old continent there are those who had already thought of it more than five years ago. plus the advantage is not having a rear wheel of 27.5 on a 29, but a 29 on the front of a 27.5.
  • + 1
 Test is somewhat in-conclusive, too many variables. Theres also a chance its a subtle advantage that only really shows itself in the hands of the best, wc professionals, riding on the edge to win.
  • + 4
 New 28” wheelsize coming for 2021, you heard it here first!
  • + 1
 No way bro, if you knew anything about the bike industry, you’d know it’ll be 28.7”


Newb.


Lol.
  • + 0
 @mikekazimer
I think the rocky was a good pick. But using the BC instinct may not give you the all tuning options, as the long shocked BC gets rid of the ride9 the standard instinct has. The Biggie-smalls will allow some of the settings to be used that otherwise would result in the tire hitting the seat tube.

2nd my personal unsubstantiated opinion of 29 is the rear wheel rolling/pedaling over things is a bigger advantage thing than the front. Front comes down to good line choice rear is the brute that has to deal with the whatever it’s being lead into.
  • + 1
 Your legs are stronger and have more travel than your arms so can deal with the smaller wheel.
  • + 1
 Eh, if you are dropping the wheel size in the back, you really need to stay in the steepest ride9 to keep the BB high and the HTA from getting super slack. This is the position that the stock BC comes with. If you dropped your ride9 to 5 or 3 (my gabs with 150mm fork) then the BB would be way to low with that 605b out back. They did it right. What they missed was just throwing on the Pipeline headset cup and going full 27.5 too. Silly to skip that tbh
  • + 1
 @Svinyard: Why would they test the 27.5? I believe Mike and the others have conclusively proved 29 is better in every way with no drawbacks, and in racing it's faster by at least 4 minutes on a 5 minute track. You don't want a 27.5. That wheelsize is slow and inferior. You want a 29er. 29er is good. 29er is life. 29er. Yes. Wink
  • + 2
 A year or so ago, I broke a Stans rear hub (No surprise there!) on my 27.5 bike. I threw on an old 26 inch rear wheel and... couldn't tell much difference.
  • + 3
 This conversation should be based around rider height more than anything else.
  • + 4
 Brent Foes has been out in front with this for about five years now.
  • + 2
 I just got a Mixer Enduro and had my first trip out to DH park this past weekend. It was amazing as compared to the Foes FXR i used to have. All my friends that borrowed it for a lap were just as impressed.
  • + 3
 I learned that if you ride the same trail multiple times you get better at it.
  • + 3
 Bruni and Maes probably would have won regardless of what wheel size they were running.
  • + 4
 so the more you practice a track, the faster you go. surprising.
  • + 1
 2 things:
- you can't make any relevant conclusion on any topic with 6 events. That's not how works statistics, or just sciences.
- When is scheduled a proper REAL test including zombie 26" ?...
  • + 4
 these unscientific tests aren't helping anything.
  • + 2
 I’m really digging the new mullet and superboost bikes. finally something I 100% don’t give a f*ck about, think it’s complete bull shit, and can save my money.
  • + 2
 Just wait for the new wheelsize
  • + 2
 I'm not buying anymore bikes till someone makes a frame that accepts wheels from 24" to 36". My future stable will consist of one frame, five wheel sets. And lots of Stan's.
  • + 0
 I bought a 26'' frame to suit having a wheel cover on my rear(see my profile), then got a 27.5 fork so I can have a special front wheel - which only comes in that size - to match(pictures will eventually be posted - project bike isn't finished), so I do support this......Especially since it saves weight(project bike will be 30lbs with 160mm travel)... Personally, I won't ever go past 27.5/26'' - I understand the benefit of the taller wheel, but I'm not a racer therefore don't have to blast downhill & over rough areas constantly - I will only go Plus to both add roll over ability & traction(where WTB's Ranger tyres are the lightest I've found so far - lol)... How about testing my theory? Why not try a 27.5/26'' Plus set up, & compare that to a 29er? PS: Seems my ideas have good potential to be of benefit... =]
  • + 3
 I think it would work better if you tried to preserve close to original geometry by overshocking or offset bushings
  • + 1
 me and my mate were just out on our bikes and were arguing over that 0.05 of a second difference in our bikes. it really spoiled our enjoyment of the trail........ oh wait that didn't happen..... just ride you bike. !!
  • + 1
 wouldn't you achieve the same results with a 27.5x2.5 / 27.5x2.3 tire combo? I mean the difference in measurements is so small.. @mikekazimer
  • + 3
 29+ on the front and 24 on the rear...
  • + 1
 What is the right execution of a mullet Bike? Do you take your 29er and put a 650b wheel in the back or do you take a 650b bike and put a el 29er front fork/wheel?
  • + 2
 Um... it’s so obvious. The Penny-farthing bike!

19th Century for the win!
  • + 2
 on of my favorite wheel size quotes "If you can't tell the difference whey do you even care?.."
  • + 1
 So if a 29" bike is just as fast with a front 29" wheel and and rear 27" wheel, would a 26" bike with a 27.5" front be just as good as a 27.5?
  • + 1
 They're basically letting people know there are ways to save money and get some benefits. Why that has become cause for arguing is odd to me.
  • + 1
 Uh...no mention of the fact that smaller wheels accelerate faster. Of course they also have a lower top speed...hardly a limit that cab be reached on a bike however.
  • + 2
 "...thereby preventing uncomfortable tire-to-pants contact"
Never a good thing.
  • + 1
 PAAshaa… been doing stuff like this for years --- just for kicks.

bike industry is doing it just to boost sales with "look at what you're missing out on' marketing
  • + 1
 It would be fun to get 30 or 40 riders of varying ability together and do a test with a large enough sample size to actually have some confidence in the results.
  • + 1
 makes sense to have the mullet setup. more advantages than anything else. only thing thats bad is having to carry different tires rims, but i only dent my rear rim
  • + 2
 Faster for what , my world cup campaign , yeah yeah it makes all the difference.
  • + 1
 Love this new mullet style. Rode my v10 a couple years ago with a 26 rear and 27.5 front. Loved it! It jumped well and monster trucked through the rough stuff! It was a blast
  • + 1
 Razor scooter wheel up front and 29er in the back. works best for the steep downhills, always wear a chest cam when trying new configurations.
  • + 2
 Some tracks may be faster with the mixed and some may not. Also depends on the course.
  • + 1
 When I first started riding there was a big thing about 24 on the back and 26 on the front...history repeats itself as they say.
  • + 2
 What about using offset shock bushings to lower the BB height on the 27.5 bike with a 29er front wheel?
  • + 2
 HA will be slaaaaack
  • + 1
 slack ha and sa , affects pedaling response. not a bad route though
  • + 1
 I'm glad two months ago I decided to start growing a mullet. I like the naming convention of these 29/27.5 bikes. Would a 29 / 26 be a Tennessee Waterfall?
  • + 1
 have a 27.5+26 rear as i had no money for a new 27.5 wheel lol....still don't ride any faster/better
  • + 1
 My Commencal Meta HT AM is running 27.5x2.8 rear 29x2.4 front.. works great.
  • + 1
 A cool way to make your current bike obsolete and sell a ton of new frames built to the new "mullet standard".
  • - 1
 Yes of course they are remember when you had a 26 with a skinny rear and fat front tyre same thing just suprised it took this long to find it out still you know 26 aint dead it was a learning curb lol
  • + 2
 Reverse mullet. Long front short rear! Just ride you nerds!
  • + 2
 Plot twist.......it’s always been the rider!
  • + 2
 Question, along the lines of speed and diameter. 6.5 creedmoor or 308.
  • + 2
 what about a 27.5 frame with 29r front????seems good to me...
  • + 1
 I recently built my new 26" bike, I was already feeling sad and lonely, now I feel so slow too.Frown
  • + 1
 I'm going for a 700c Rd wheel on rear and 24inch on front it's amazing fast as fuck on my paperorund
  • + 2
 Reverse mullet business in back party in the front
  • + 3
 PENNY FARTHING
  • + 0
 Isn't "mullet" a misnomer here? These are "reverse mullets" with the long in the front and the short in the back. More of an "emover," really...
  • + 12
 The big wheel is the business in the front, and the smaller wheel is the party in the back.
  • + 1
 If you add all the 29'' times and all the 29/27.5'' you will realize the MIX is 4sg faster.

That is the answer.
  • + 1
 I have a friend who's still rocks a 27.5/26 combo until now, long before this thing came.
  • + 2
 I was just thinking...”Where’s the 27.5 front/26 rear comparison for magical bike park fun?”
  • + 1
 Also, I’m short.
  • + 2
 @sos-dirt: I think my might try squeezing a 27.5” under my 2014 Fox40 and give it a try. I too am vertically challenged and I’m not replacing my V10 anytime soon.
  • + 1
 @benz-tech: 26" 40's fit and ride good with 275 way to go
  • + 3
 kill me
  • + 1
 Should be called a 'Penny' – short for Penny Farthing with the big wheel up front.
  • + 1
 Enduro motorbike have this setup for ages. It should work for bicycle too
  • + 1
 Why can't people just ride their bikes the way they are?
  • + 1
 I run a 14 in the rear and a 31 up front. It's badass!
  • + 1
 Conclusion : still love my 26 inch wheelzzzz
  • + 1
 I sent an email to rocky to get their views and do not recommend it
  • + 0
 No one talks about FOES that have been selling that bike concept for what... 2 ou 3 years?????
  • + 7
 There's a link to the review of the Mixer that RC did here on Pinkbike in the article.
  • + 0
 @mikekazimer: my bad, there is a clear reference in the article, but they were never taken seriously, were they?
  • + 2
 What about 28,25 rear?
  • + 1
 wow haha so funny great humor
  • + 1
 When will see 26/29 mullet bikes ?
  • + 1
 Sometime in the 2000's, *Trek* *Cough*
  • + 1
 36er, 29er combo will dominate before the end of the season!
  • + 1
 In the next installment, clips or flats with the mullet bikes.
  • + 9
 No brainer; one of each, just like the wheels.
  • + 2
 26/27.5?????
  • + 1
 Now that would be fun!
  • + 1
 Thinking about 27.5 front 26 rear on my 26 ht, would need to lower my 27.5 to keep geo close to what it needs to be.
  • + 2
 I'm going to do this with my 26" hardtail.
27.5" wheels fit just fine in all generations of Fox Forks. If you have a Talas, you can get the best of both worlds by dropping your front for climbs. Does bring your BB a little closer to terra firm though...
  • + 1
 @schooledrider: It is fun! Do it!
  • + 1
 Definately needs to be called the 650b + 29er = 69er
  • + 3
 69er be a 26" rear and 29" front. Make for a pretty steep head tube angle, but might be interesting.
  • + 4
 @woofer2609: Head angle is pretty important in a 69er if you don't want to end up in the stink.
  • + 1
 I don't know, but it looks seriously fugly.
  • + 5
 Yeah, 29" is just awful
  • + 1
 Why ruin a good 29er by sticking a little wheel in it.
  • + 2
 What time to be alive
  • + 1
 Let’s not forget Treks Travis Brown inspired 69er.
  • + 1
 Motocross bikes have mismatched wheel sizes........just sayin....
  • + 0
 A mullet bike is small in the front big in the back all of this is completely useless
  • + 1
 nice "pick n pull" bike
  • + 1
 Mullet bikes? lol
  • + 1
 Reverse Mullet
  • + 2
 @dtsabas -- you are correct sir...I've never heard of a mullet long in the front and short in the back. Not sure what that's called
  • + 9
 @enger: business = 29er, party = 27.5er.
  • + 1
 @brianpark: I take it people have somehow never heard of that description. It is definitely the mullet of bikes.
  • + 3
 @brianpark: I've called my preferred tire setup the reverse mullet for awhile (regardless of wheelsize). It's a big knobby tire like a DHF 2.5 paired with a fast-rolling tire like the the Ikon 2.35 in the back. Party up front (traction / cornering), business in the back (speed). It's fairly common combo in the southwest.
  • + 1
 @NoahColorado: time to mix your wheel sizes
  • + 2
 Wtf is a reverse mullet? An undercut?
  • + 2
 @me2menow: the "I need to speak to your manager" haircut.
  • + 1
 Party wheels!
  • + 1
 I call mine a. 27niner.
  • + 1
 "Frullet"
  • + 1
 650B + 29 = B9’er
  • - 1
 No, size is much much much more important than geometry.
  • - 1
 he likes to ex-spearmint that's for sure.
  • - 2
 It’s a blip for sure.
  • + 2
 Naw dawg it’s got life for people with open minds who like to have fun
  • + 1
 @Purpledragonslayer: It will only catch on when there is a new in between wheelsize, big 29er on front and 27” on back looks too strange
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