Chris Porter Talks: GeoMetron 29" Prototype

Dec 22, 2015
by Paul Aston  
Nicolai Mojo Geometron 29 Prototype
I think the big wheeler might need a hug after reading this.



I took a first ride on the Nicolai Mojo GeoMetron earlier this year. Since then I borrowed another similar version from one of the Nicolai engineers, which I put through it paces over a couple of weeks on the Italian Riviera. Passing through Risca recently, I dropped into the Mojo unit for a chat (coincidentally my forks were due a service, and I needed a coffee) and there she was: Hanging majestically from the work stand, I lay my eyes upon her, having no idea of her credentials. Hang on a minute, are those 29" wheels? Chris replied "Yes, it has just come in, I still hate them, but I wanted to build one to shut you, Steve Jones (from Dirt Magazine) and Alan Muldoon (MBR) up, as you guys never stop going on about how much you love 29ers. I'm going to prove they're not better." Over the course of drinking my americano, I persuaded Chris to let me take it on my onward journey to Madeira for a couple of days. It took a while to fit it into the bike bag, and further issues came when trying to get it out of the bag, getting it to fit on the bike shuttle, in the public bus and into the hotel room – even some of the streets struggled with its size. I had a great time on it, and would love to do some back to back runs with both sizes in the future. For now, here's the caffeine-fuelled chat as we watched Paul the technician gently ramming the monster into the bag.

bigquotesYes, it has just come in, I still hate them, but I wanted to build one to shut you, Steve Jones (from Dirt Magazine) and Alan Muldoon (MBR) up, as you guys never stop going on about how much you love 29ers. I'm going to prove they're not better.




How have sales and feedback been from the 27.5" bike?

Sales of the 27.5" version have exceeded all expectations. We’ve sold more in six months than we planned for the first year. The general acceptance has been amazing! No-one has ridden it and not liked it (Alan Muldoon from MBR had some criticisms, but he was riding the wrong size and using his ‘test ride’ as a geometry experiment – we weren’t in control of what changes we made, he was asking for them). In fact, the number of people who have bought bikes following test rides is amazing. Quite a hit rate!

Nicolai Mojo Geometron 29 Prototype

Do you think people have gotten over the initial shock of the 'crazy' angles, and now accept this as a viable option?

I reckon the fact that all of the Nicolai staff have been using versions of our GeoMetron and they have released the Pinion gearbox equipped bike with our ‘crazy angles’ shows a level of acceptance. A real production bike with our angles. Everyone that rides it accepts the geometry without question. After an initial “it climbs OK, turns well, seems pretty good in tight corners” period, they all just shut up and ride! The major feedback I get is when people go back to their normal bikes and email me afterwards to say how awkward, small and twitchy they feel.

Nicolai Mojo Geometron 29 Prototype

We talked a lot about wheel sizes when I came to test the GeoMetron. You seemed very anti-29" at the time. What has changed, why have you built this?

I’m still not a fan of 29-inch wheels. There’s too much gyroscopic effect at speed. They feel OK in certain circumstances but when it gets fast and direction changes are at speed they feel very limited. The reason I built it was literally to show that the 27.5 version is better! There was quite a bit of talk amongst 29er fans of how much better this bike could get if it had 29-inch wheels. That’s why I built it.... The 27.5 GeoMetron has a lot of the good traits of 29er's (speed over rough ground, speed through turns, calmness of steering, etc...), but also steers well at speed and is very much more dynamic than the 29ers.

Nicolai Mojo Geometron 29 Prototype
"Looks good from afar, but far from good"...
Nicolai Mojo Geometron 29 Prototype
...the opposite is true with the Nicolai, she's a beauty in the flesh.

Can you explain why you think that the 29" bike won't be as good as the 27.5?

The 29" version has a much lower bottom bracket in relation to the front axle, so front wheel braking traction and turning traction (at the corner entry point) will be compromised as the weight transferred to the bike from the feet is pushing under the axle and pushing the bike forwards. The lower BB height also means you can’t manual and hop properly. Basically, anything other than an SPD pull-up to lift the bike takes more effort and more time to achieve and time doesn't always allow for this on the trail. It encourages a wheels on the ground riding style. I feel that you have to lift the body to change direction... It’s just a feeling but it is definitely harder to change direction from one side to the other and it feels like it’s a fight. I think that’s precession (gyroscopic effect). I find it nervous in a straight line until it's up speed then it's great. But then at speed, it won’t turn.

Nicolai Mojo Geometron 29 Prototype
The GeoMetron looks suspiciously normal with the big wheels.

Will you be putting these into production?

We’ll build them! I’ve sold 3 of them already, if people want to buy them they are still an interesting bike, they share pretty much all of the geometry numbers of the original, just adjusted for the wheel size. It’s not like we just built a Tall Boy copy!



Somebody builds a one-off bike to 'prove' it's not as good as another, but then sells three of them with zero advertising or promotion – what does that tell you? Specialized had a good stab at long legged big wheelers with the Enduro 29, then seemed to back off the offence as they put more effort into 650b and plus sized tires. A few other brands have had a pop like Banshee, Evil and On-One for example. But nobody has really gone all in, yet, with designers seeming to make things shorter and steeper compared to their little brothers to offset the supposed negatives of big wheels, or maybe just to make numbers look more controllable on paper. Time will tell, but interesting times are here. - Paul Aston


MENTIONS: @mojosuspensionmedia / @paulaston






205 Comments

  • 198 13
 So if 29" handles like a barge due to gyroscopic forces, and 650b is more manoeuvrable and easier to manual, how much better would 26" be than 650b!? Crazy idea huh! Why build something to prove it crap when you could build something to prove its awesome!
  • 11 4
 Yeah, that's what I was thinking. It sounded like, "I'm really good at making bikes, but let's throw a monkey wrench into the mix for good measure, just to test". Kind of like making a harpoon, but then saying, "the arrow needs to load backwards, and rotate throwing knives style, or I'm not happy".
  • 67 2
 I thinks it's more like "if I build this will you all stop banging on about it"
  • 37 3
 @chrisporter Just watch Luke Strobel ripping it: www.youtube.com/watch?v=EnoimrkIsn8 and www.youtube.com/watch?v=hUOIPuu4UvY

I appreciate all wheel sizes, and totally enjoy the playfulness of 26ers, but saying 29ers can't corner is just plain wrong. Yes, it may be a more on-the-ground riding style, and yes, not everyone might like that, but they are crazy fast. BB drop is actually a good thing, too, and today's brakes can handle the front wheel very well.
  • 31 5
 Well, 26 is way better in berms, but is simply worse on rough stuff, because 27.5 rolls over obstacles better. Wheel size is just a matter of compromise, like everything else.
  • 26 0
 All I know is that I love my E29, handles well under all circumstances and as far as do it all bike it is ticking most of the boxes. Having a 12,7 kg trail bike that can climb anything and go down wherever was unheard of just a couple of years ago and for that I'm grateful you marketing mambo jumbo standard confused bike industry. Merry Christmas everyone!
  • 8 4
 Another +1 for the E29. Also the ibis Ripley which feels like a 26" bike handling wise.

I think maybe super slack 29ers like this one may well be not work so well.
  • 14 2
 At a recent talk in Sheffield Chris Porter said he prefers 26 but understands that its on it way out so 650 is the next best.
  • 18 2
 He can't prove any of them more awesome than any of the others, because awesomeness is an opinion. Any of the wheelsizes work great, but it is easier to smear one wheelsize for the adulation of the other fan group. this is literally the biggest piece of troll work on pinkbike, waki better step it up if he wants to keep his cred.
  • 4 0
 I think you'll find Waki likes Chris Porter's ideas!
  • 8 0
 @pinkbike When can we expect a review ?
  • 6 2
 Its almost impossible to find slack 29ers at present. I've managed to get mine down to 66deg and it feels great, would be better if it were slacker still. The whole '29ers suck on steep stuff' thing is purely down to geometry in my mind. It leaves me with a difficult decision now though.... should I buy the 29 or 650 geometron as my next bike?
  • 7 1
 @graeme187 - I like to ride my Kona Honzo ( 29er hardtail, 67 degrees h/a with 140mm Pikes) down the steepest stuff I can find and while my DH bike is faster it never ever felt sketchy. I honestly wouldn't mind riding down Champery with it (at a snail's pace mind you).

I often forget I'm riding the little bike until I hit a bunch of rocks..
  • 22 0
 iv been makin 26" hardtails with similar geo to this for years...but no-one listens to me...

www.pinkbike.com/photo/11528213
  • 2 0
 I almost always agree with CPs ideas. My own experiences have taught me that longer bikes are better, slacker head angles are usually better if the rest of the geo backs it up, but also that bigger wheels are better. At least that is I find 650b an improvement over 26" for flat out speed over rough ground which is what I enjoy (I still ride a 26 DJ bike, there are obviously times when 26 is gonna be the better choice). But now I'm looking at these new 29ers with proper geometry and thinking could they be better still? CP sounds like he's got a chip on his shoulder about the bigger wheel sizes (as do many in the PB community :-P) I'm not convinced by his gyroscopic argument yet...
  • 2 0
 Same with me on my taro.. Just thinking an angleset and a beefier fork would make it even better
  • 7 4
 Yet 26"wheels are capable to generates more speed than 27.5.Where the big wheels
roll over an obstacles carying speed ,the smaller wheel will carry the same speed but will also go in and out , up and over very much like a pump track....smaller wheels are just as quick , slower in certain conditions but also quicker in others
  • 1 0
 @madm3chanic more info please? Do you sell them or you make them for yourself? Material, weight, geo? I haven't found the perfect HT yet, seems like I'd be better off making my own*, so I'm interested.

*if so, go all in and make a lower and slacker PP Shan out of titanium
  • 3 0
 @uuno- www.descendence.com mate Wink titanium or triple butted 4130 steel :s geo anything at all, weight between 4 and 5 lbs.
  • 1 0
 My bad, I spoke before I checked your profile. I will probably get in touch one day!
  • 1 0
 @madm3chanic how much (roughly) would postage cost to U.K.?
  • 3 0
 The Following is 66 HA in low. Throw a -1 in there. Their new 29" is is gonna be 160mm and 65 HA in low setting.
  • 3 0
 I ended up with a 29er enduro over a 650 enduro. Purely down to price and so far 2 months in im not seeing any issues. My big concern was if the wheels would take the punishment i would be giving them. So far so good, its pretty sorted.
  • 2 1
 I have to agree with CP's comments regarding the agility of a 29er when changing direction, I own a norco shinobi and have spent a good amount of time on a slacked out custom AC29 and a custom ion15 with a 65 deg HA. I absolutely loved the ion15, it was so confidence inspiring it just made you want to go looking for trouble and was the bike I was going to upgrade to until I tried the geometron, which had the same confidence inspiring stability through anything steep and rough, but was noticeably more agile particularly transitioning from corner to corner, the ion15 had Enve wheels as well so it can't be blamed on overly heavy wheels. The geometron blew me away so much I had to buy one.
  • 2 0
 If precession is the problem, the solution would be a different style of changing direction. If you want to turn left, then try to bank left and the bike will yaw in the proper direction. I'm saying "try to" as applying the moment to bank will already yaw the bike. I thought this was a common approach for turning already (except for maybe road cyclists). Just like whipping when off the ground. The precession is always there though obviously larger with the bigger wheels.

Not that I prefer bigger wheels though.
  • 1 1
 I have sat and watched people at races and on the trail. Especially if you are a shorter rider, bigger wheels appear to be harder for people to handle and maneuver. Sure. they roll over stuff easier, but i just do not see that outweighing the pretty large negative aspects.

Buy one of our frames. They roll over stuff better than anything out there, and they are still 26"
  • 1 2
 Made in Germany, ,,,check. FSR linkage check.
  • 2 1
 That's why I've found it to be really important to minimize rotational weight on 29ers. It makes a huge difference.
  • 1 2
 My only gripe about 29ers is that they are very hard to slash corners with, I mean cut inside and square off to the end of the berm as they have so much grip its much harder to get them to break traction mid corner - I bought a 29er in the first place because after 20 years riding 26 I wanted a different experience, different way of riding, not less fun just different. But this is the one reason I'd consider going backwards and downsizing to 27.5
  • 5 0
 I'm by no means tall (about 1.76m on a good day) and have a bmx background but I have no issues either railing or drifting a tight turn on my 29er. I've had lots of proper 26 inch bikes before and I'm pretty confident none has ever come close to the Honzo when it comes to cornering.

It might be a little bit harder to break loose but when it does it's a lot easier to keep it sideways throughout the turn.
  • 3 0
 I have a honzo and it's an amazing frame, it shouldn't work so well but somehow it does
  • 2 0
 Yeah same here, it really has the character of a DH bike. My only gripe would be the frame weight, which could have been a lot lower IMO..
  • 3 0
 Are all the Honzos as good? I'm looking at a 2012 Honzo that's been fitted with a 2015 160 Pike.
  • 4 0
 @Uuno - depends on the build (mine's custom built, 140mm Pikes, Zee stuff, Minion/Ikon, 40mm stem with uncut Fatbars) but I think 160mm is a bit much as it will raise the bottom bracket too far, at the cost of grip and handling. Other than that, the standard build is quite decent, only a bit on the heavy side.

You can easily lower it to 140 (which I prefer) or 130/120mm by replacing the air piston. Should cost around 30 euros if you do it yourself.
  • 2 0
 I've got 140 on my honzo, 160 might be a bit too much. It's a portly frame but I never really notice it while riding and managed to cope fairly well at Bike Park Wales with my mates on their budget to boutique 120 to 160 full suspension bikes. If weight is an issue for you then the honzo now comes in Steel, Aluminium and Titanium. I believe in previous years the Taro was the same geo but slightly cheaper.
  • 3 1
 This guy is trying to stick to his guns, even when his guns have no bullets left.
  • 84 3
 Pick a frame geo and then be a dick about it..
  • 16 0
 where is MEGATRON!!
  • 5 5
 So who is being a dick?
  • 2 1
 @BDKR from Pinkbike memes history Wink
  • 2 1
 @dbodoggle : Yeah, I've seen that video. I was just curious if you thought it was Chris or Paul that was busy being a dick.
  • 3 0
 It wasn't so much point fingers at a specific person. It was moreso to address the closemindedness that has been observed in the industry over the years. That's all.
  • 30 0
 Yet another bike I would like to demo. Isn't Niner bikes "all in" regarding 29" wheels.?.
  • 5 0
 In terms of their lineup, yeah, but I think Aston was talking more about geometry.
  • 1 1
 ...so is BMC (except for the market driven 650b trailfox version) and I share the geometry aspect even more with the 29er´s. The geometron ahhhh
  • 3 2
 Looks like a Banshee Prime.
  • 17 12
 26 > 27.5
  • 23 2
 Actually, @dars51, 26 is less than 27.5. But I see what you mean within the context of wheel size on a mountain bike.
  • 1 2
 Technically, 650b=26 in metric to English terms...
  • 1 1
 @listeryu You mean the 650b Speedfox Trailcrew, with the unrideably low BB.
  • 1 0
 Haven't tried it - havea tf02 29" and it works really great
  • 3 0
 @cogsci No such thing as an unrideably low bb, let the pedal smashing continue!
  • 29 4
 Great, but now I want to see what one of these will be like built by someone who wants it to be better than the 27.5 version.
  • 3 0
 @BrownestBiker I completely agree with you. Maybe Mr @paulaston , Mr Steve Jones and Mr Alan Muldoon could be locked in a room together with some paper, a scale rule and a protractor and design one for Nicolai to prototype.

That aside I still wait with baited breath for the review from Paul.
  • 6 0
 Agree. Being a 29er rider myself, I'm certain that I could fabricate a 29er myself and I would absolutely hate riding it compared to a readily available 27.5" bike. So if you set out to build a 29" bike for the sole purpose of proving that it's inferior to a 27.5 model, you have doomed the endeavor from its onset and haven't really proved anything at all.
  • 18 3
 So lets build a 29er with the same geometry as our 27.5 bike and all rip our dicks off wondering why it doesn't handle well. Sounds a lot like the first generation of 29ers to me, seems like Chris needs to get his head out of his ass and realize that there is a place for 29ers whether he likes it or not.
  • 3 1
 Builds a 650b that shreds, builds a 29er with the same geometry and... it shreds. I think the biggest weakness of 29ers has been the insistence of the industry in making them all short and steep to 'compensate' for the extra stability of the wheels. Now proper forks, wheels and tyres have caught up with the increase in size there's no reason to not have big mountain capable 29ers, they're too much fun to smash over rocks to leave to the XC and Roadie types.
  • 17 2
 The guy can't get a break. Tries to build a bike to show it's sh*t and people love it!
  • 7 1
 Reminds me of the movie, the other guys, where Mark Wahlberg learns to dance ironically, just to make fun of another person...lol
  • 2 5
 People who like it aren't people who are...

1) ...riding in the manner that he is talking about
2) ...think 29 is good just because it's 29.
  • 1 0
 Be interested to see what Steve Jones thinks. He definitely rides in the manner he was talking about
  • 2 1
 @multialxndr : I agree, but the large majority of peeps I come across on wagon wheels ride like pu55ie5. If you're not one of them, rad!

They also tend to mimic that same old crap from the guy who sold the bike to them about how it rolls over crap and goes faster. Blah, blah, blah...... I would be more impressed if they took that thing to their or it's limit then gave feedback based ON THEIR OWN EXPERIENCE.

I actually think some 29's are rockin' and seriously looked at a couple before getting a Canfield Balance.
  • 1 0
 @bdkr But.. that is what 29ers do.. They roll over things more effectively and have a higher open trail speed. So maybe that is their experience? Plus, isn't it okay for people to ride in a manner they are comfortable with? Must everyone be Xtreme? For the record, I've owned and ridden two 29ers in the interior and North Shore of BC. Trek Stache and a RM Instinct. Both of which rolled over things more easily than a 26/27.5" and had a higher open trail speed..
  • 11 0
 I don't want to cause a neg prop storm, but I'd be really curious to try a 26 version. I'm thinking about the added agility in corners...could be a beast.
  • 4 0
 I think we have all been cured of wheelophobia no on has turn the comments it a wheel hate debate......... Yet
  • 2 0
 Yeah, pretty weird, eh?
  • 8 0
 I'm from the USA, but I've been watching a lot of trailer park boys lately, so I've been saying eh a lot. Forgive me, I'm not a poser, eh
  • 9 0
 Screw you Randy, I'm not ascared of you and your fancy white pants!
  • 3 0
 Samsquantch- I hate those bastards
  • 4 0
 Have i missed something?
  • 2 0
 Our version of Coronation Street-the Trailer Park Boys
  • 2 0
 in the MTB industry what comes around is all around, when 26 comes back remember atoadaso, a f*@!$n' atoadaso
  • 4 0
 Frig off ricky!
  • 2 0
 Someone call Jim Lahey, Randy is soliciting himself for cheeseburgers again.
  • 3 0
 What's with the Smokey outfit Randy?
-Man's gotta eat.
  • 9 0
 CANFIELD RIOT!!!! Its been my mission to put this bike under anyone who has even the slightest hesitation of the big wheels....Bottom line, when you suspension is dialed and the geo matches, you can NOT have anything but fun! Crazy fast and carves corners like a dream!
  • 4 0
 Hurry up and get them in stock!
  • 5 0
 Canfield Riot is a awesome 29er with 66.5 HA with 16.3 CS. Have had mine for little over a month now and this bike is stupidly fun to ride, it "manuals and hops properly" over everything.
  • 2 0
 RIOT frames are in stock end of FEB. Glad you are digging the bike in2falling !!
  • 4 0
 What Sean said. ^^^. Canfield Riot has got it going on in the geometry department. Nothing even remotely close.
  • 15 7
 I'm a huge fan of Chris. He is one of very few radicals who make sense and actually provides "radical" solutions. Cool to see his take on a 29er. I wonder if he has somecrazy ideas for own frame, suspension or even fork design.

Cheers!
  • 3 0
 He has his own bike made by Nicolai with 27.5 / 650b wheels. Of course the suspension is custom tuned by him ('cos he can) and he has to service the fork quite often due to the super raked head angle. He's pushed the envelope right to the limit with his bike design. Not for everyone - but it's good to have people like Chris Porter and Steve Jones to throw ideas around and stir the pot!
  • 7 2
 I meant that maybe he could have designed a frame from the scratch, not use Nicolai (nothing to those guys). Servicing fork more often? Did he say that? It seems that his fork should need less love since by being slacker it works more in line with the direction of forces coming at it. I'd speculate that bike with slack head angle and fork with longer travel has better roll over than a bike with bigger wheel and steeper HA and less travel.
  • 2 2
 He is one of the more knowledgeable people in our industry
  • 2 0
 At a lesser extent both fab Barel & Dan atherton think in the same vein as CP
  • 1 0
 Waki, absolutely you get much better roll and traction. No need for a 29er version.
  • 3 0
 Agreed - it's good to have outliers in the industry to shake things up.

One thing I'm surprised about here, though - he seems not to understand that the gyroscopic effect problem he talks about is a matter of scale. I'm a 230# rider - so to lean over a 29er at speed is proportionally no harder for me than it is for a lighter rider to do so with their smaller bike. A smaller wheeled bike actually leans over way to quickly and easily for me - leading to a twitchy sensation I don't like very much (and yes, there's a difference between twitchy and playful - I like the latter, loathe the former). I bet if he were to look at the people who like his new 29er, he'd find their bigger dudes who can take advantage of the advantages of the bigger wheels without being hamstrung by the big wheels being overly stabilizing at speed.
  • 1 0
 Just wish it had a bottle mount inside the frame
  • 14 7
 "so front wheel braking traction and turning traction (at the corner entry point) will be compromised as the weight transferred to the bike from the feet is pushing under the axle and pushing the bike forwards"

Err, nope, as far as traction is concerned, physics says otherwise. It's about the relationship between the centre of mass and the tyre contact patches (i.e. BB height and distance behind front contact patch), not the relationship between the centre of mass and the front axle.

When cornering off the brakes (i.e. assuming no rear-> front weight transfer due to braking) , force (weight) is only transferred to the ground through the tire contact patches, and it makes no difference to traction where the axle height is in relation to the total system (rider & bike) centre of mass.

When braking, the weight transfer is a function of where the centre of mass is in relation to the front contact patch, and (as long as you don't lock up the front wheel) is also independent of the axle height. [Once you lock up the front wheel and start going OTB your contact patch becomes a 'VPP', in which case wheel diameter does make a difference - the larger the wheel diameter, the more your lever arm grows as you roll up onto the front of the wheel].
  • 9 3
 Haha I had an image of all these 29ers locking up front wheels and skidding after reading the initial post, then I remembered that doesn't actually happen and they in fact have loads of grip! The 'science' presented as fact in many of the marketing spiels in the mtb world are the product of mechanics and graphic designers thinking they know anything about engineering principles, its truly laughable!
  • 8 3
 I think his mentioning "at the corner entry" is critical here. Forces applied while the bike is straight up and down is one thing, but WHEN TURNING IN WITH THE BRAKES APPLIED throws all of that askew. Now, of the available traction, some of it must now be used to deal with forces that are not longitudinal.

In racing terms, the bike is more likely to push in this circumstance.

You referred to the physics while upright and braking, and while cornering off the brakes. I did not see a specific mention of that period of turn in under heavy braking (because we're only going to get significant weight transfer along the longitude under heavy braking).
  • 4 0
 What happened to not braking in corners?
  • 2 2
 dsut - in my understanding, the BB drop in relation to axles has an effect on fore-aft balance of a bicycle because this is how riders body is suspended into the bike. In terms of fore-aft balance, wheels are virtually a part of the ground. Just a thought.
  • 1 1
 @uphilarious : Cornering has multiple phases, be it car, bike, motorcycle, or even a fighter. Each has it's peculiarities of course.

"What happened to not braking in corners?"

Let's ask two questions instead of one.

1) What happened to not braking in corners?

I'd have to agree that's not always the best thing to do, but that may depend on circumstance (did you overcook the entry or is the corner radius decreasing?) and the dynamics of the bike you are on (some motorcycle guys like to use the rear brake mid-corner to help settle the back end or control wheel spin). Another reason to use it may be mid-corner attitude adjustment.

On a mountain bike, I'm game for mid corner braking with the rear, if I feel I need it. I stay away from the front mid corner. Going through the limit of front traction while leaned over sounds like a good way to end up on your head.

2) What happened to not braking INTO corners?

Ever heard of trail braking? Read this --> en.wikipedia.org/wiki/Trail_braking

On a mountain bike, I trail brake with the rear, unless it's a berm. On road motorbikes, I trail brake in on the front. If I wanted to go in deeper, I also backed it in using engine braking (as opposed to the rear brake). Check this out. --> www.youtube.com/watch?v=P4A91t2RQKg

I guess I'm trying to say that there is no absolute hard and fast here. While some things may not be suggested, there are viable reasons for doing them from time to time.

And it's fun. :-)
  • 1 0
 @dsut4392 is correct on all counts. The BB is still in the same position relative to the tyre contact patches; where the axles get moved up to has no bearing on how the load is transferred. You can't "push under the axle" in the way that Porter says you can - his understanding of physics is quite poor.
Source: 4 years of studying this stuff + another 4 years working on vehicle handling professionally.
  • 1 0
 What about suspension squat?
  • 1 0
 I totally agree BB-height in relation to Tyre patches is what matters most, in most situations, however when you consider dynamic rider input the BB-drop in relation to axles becomes more of an issue. For instance it is easier and smoother to lift the front of the bike that has less BB-drop. A 29er with lots of BB drop is weird to wheelie (like when you try to ride over a mud pool) it is hard to get the initial lift, then it suddenly pops up. For comparison a 24" bike like Inspired goes for the rear wheel in a very smooth way
  • 1 0
 It does affect the ability to pop the front wheel up because the vertical load through the BB has a certain moment arm (lever arm) about the rear axle, and any BB drop will mean the moment arm increases first before decreasing. However, in that case, the bike is effectively rotating about the rear AXLE not the rear tyre contact patch. It is nothing to do with grip. Comparing a 24" bike with a 29er is quite unlikely to be a fair comparison to BB drop as I can all but guarantee the chainstay lengths are nowhere near the same.
Edit: I can see how people would not understand why this is. Your centre of mass does push down through the BB as it is more or less directly above the BB in a static standing position; in this case the force acting on the centre of mass (gravity) is in line with the BB. However, it doesn't "push forwards through the BB" under braking (or cornering) loads because those loads are applied through two planes, which are the ground (which we'll call horizontal) via the contact patch of the tyres, and a parallel plane at the same height as the CoM (via the inertial forces of the CoM as a reaction to the tractive force of the tyres). Neither of these lines/planes of force are related to the axle height or BB drop.
As @dsut4392 points out, once the rear wheel lifts off the ground under brakes, THEN the BB height relative to axle becomes somewhat relevant (and still in no significant way IMO) because then the BB is actually moving slightly/more rearwards as it pivots around the front axle (not the front contact patch as it was trying to prior to the rear wheel lifting), which will shift the centre of mass in a different manner according to differing axle heights.
  • 1 0
 Cool. Thank you for that, Inever thought about it this way. Off course lifting the front is a BS because if you can do it right then there is little difference whether you ride a fatbike or a road bike. So in general, there is no advantage to 650B wheel over 26, what so ever since roll over and contact patch can be easily compromised by poor suspension setup and not optimal tyre pressures.
  • 1 0
 @Socket : I don't think anyone was saying dsut is wrong. I know I'm not. What I am saying is that Chris described a set of conditions that was not covered by dsut. In particular, the initial turn while trail braking.

Did Chris describe it in terms that are sensical or correct? I'll leave that to you guys. But the real crux of the conversation is behaviour at turn in while trail braking, and I suspect he's right, regardless of how he described it.
  • 1 0
 Most Joeys are trail braking all the time...
  • 1 0
 @BDKR axle height is still irrelevant in that sense. As far as the contact patch is concerned in that scenario, your wheel could be 16" diameter or 36" diameter and it wouldn't make any difference if all other geometry was retained. As far as suspension and geometry goes, all that matters in terms of grip is simply load variation/transfer to each tyre, and the rate at which it occurs in any given situation. Given that larger wheels have indisputably lower load variations over rough terrain (was gonna say it's a long story, but it's actually a very short story - bigger wheels tag obstacles with greater horizontal displacement from the axle, effectively meaning they have more time to lift the wheel up and over it, meaning reduced load variation at the tyre in addition to reduced horizontal load component). None of that is related to Porter's claims about the BB trying to "push under the axle", which are factually incorrect.
  • 1 1
 Hmmm.....

1) Let's let the whole "push under the axle" thing go. If you keep in mind the context, the greater question is "are larger diameter wheels more likely to push during turn in while trail braking"?

2) You and dsut seem to be focused on weight transfer. Particularly along the bikes longitude and in a steady directional state. I'm pretty sure that what Chris is talking about is behavior WHEN CHANGING STATE! The moment you initiate a turn you begin to transition and continue to do so until you reach the needed or desired lean angle. This is a critical phase made more so by the fact that your available front end grip is finite, and complicated yet more when the brakes are still on. Considering that it's good practice to slowly release the brake means the act of doing so is another mechanism that's affecting the constant state of change.

3) If wheel diameter doesn't matter then there is no such thing as centrifugal force? Or are you saying that the weight of it is such that it's a non-issue? Or perhaps the load variation makes up for any negatives associated with centrifugal force. I mention this because you CAN overwhelm front traction by expecting it to do too much.... braking too hard at the approach and/or turn in too a corner. Wouldn't more centrifugal force have an affect on the contact patch, and more? I can't stress enough that there is only so much traction.

Once again, I'm not saying you and dsut are wrong. You guys are right! But I don't think you caught what he was really talking about.

What I will say is that I've experienced front end push as a result of poor conditions (wet or contaminated with oil or coolant), bumpy surfaces, over cooking the entry, power oversteer (which never happens on a bike), too much dive on the front, and simply being too exuberant at the bars when initiating a turn in. Never mind sidewall stiffness, tire pressure, fork flex, tread pattern, compound, and on and on and on..... It's a huge issue! In this case, it's one that's probably best solved by good and extensive testing with tightly controlled conditions and variables (as much as possible).
  • 7 0
 IMHO to built a great 29er, we can't just go like " they share pretty much all of the geometry numbers of the original, just adjusted for the wheel size". A halfhearted effort but still sell 3. If 27.5 break dances, the 29ers Tangos. They are so different, I adjust my riding style every time I switch wheel sizes... both rocks but the 29er just mows. I suspects that stack height affects tricks like hopping. So more works needed on the geo. 27.5 are here because the whole industry says they are good and killed 26, but 29er are still hanging on despite so much criticism and now with the big guys backing off. So smaller niche companies, like Canfield, Evil and many more will fill the vacuum...no worries. Pole bikes's 140mm 29er looks bad ass.
  • 12 2
 I have an ibis29er and an evil 29 er , frankly love them......period
  • 6 0
 I built up a rigid 29er as a commuter/road bike and used it for 6 months or so just for that. It's a small sized frame so it had around a 67/68 degree head angle with the fork I was using, Surly Krampus. I got curious how it'd be offroad and put a 2.4 front 2.2 rear rear on it and took it off road one day. Blown away by it. I was a 26er for life kinda guy before that. Put a 120mm fork on it and it is amazing. I can blow out corners and it jumps nice. I can do it everything on it that I could with the 26ers. I'm eyeballing an Evil The Following. My next bike will be a 29er for sure...
  • 8 0
 So youre telling US that 29ers with a 62 headangle and a wheelbase of 1300+ can't corner and feel tankish. Well thanks captain obvious!
  • 5 0
 I don't get how traction is reduced if rider weight is transferred more aggressively when entering a corner or breaking...
As far as i know, more weight transferred = more traction. Especially when transferred forward as he mentions. Absolutely all bikes i've ridden, lower BB meant more traction, especially in turns.
2nd, if there's one good trait i do love about 29ers is the ability get good traction, partially due to their BB being lower than the axle. I'm running tires so worn out / slick on my 29er that i would've got me killed on my 26".

So what am i missing here? i guess he knows what he's talking about, but it makes no sense to me...
  • 2 0
 The 27.5 version of the GM has front traction by the bucket load, so you probably don't need the 29er.
  • 2 0
 Saying you probably don't need more traction, isn't a good reason to pick the 650b over this
  • 1 0
 Perhaps you dont really need more traction, but that still doesn't explain the physics behind why 29er would have less traction...
  • 7 0
 Lots of talk about this radical geometry and now 29 inch wheels. Only one way to prove it, Race the Damn thing!
  • 1 0
 Oops! Replied to wrong comment.

But I agree! :-)
  • 6 1
 I race a 29 trek remedy with a 160mm pike. Thing is an absolute monster truck, though I do agree that once you're cooking it does get a bit awkward to corner. So much stability though. This Geometron must be insane.
  • 8 1
 Who the hell drinks americano? It's just espresso with alot of water. What's wrong with an actual espresso?
  • 2 1
 It helps you savour the espresso lol. Like with alcohol, you can take a shot of hard liquor, or you can sit down with a beer and sip!
  • 4 2
 I used to drink espresso, now elongating it with water helps with my addiction. I drink both at the same speed, so drinking espresso results in serious shakes and difficulty sleeping.
  • 1 1
 Yeah, this winds me up too...isn't it like adding water to red wine? If you need to dilute it, surely milk works better.
  • 1 0
 You can't compare a shot and beer. Beer isn't watered down spirit. It's like comparing tea and coffee. Both contain caffeine and.... well that's it.
  • 9 4
 It may upset some, but I wish Porter would just shut up with his deliberately 'controversial' opinions some of the time. If there isn't something he can piss and moan about, he will go out of his way to find it.
  • 8 0
 I'D LIKE TO BUY A 26" VERSION! PLEASE MAKE ONE!!
  • 8 0
 Contact Nicolai, I'm sure they'd build you one.
  • 4 0
 Chris Porter is giving you a glimpse of the future. The only other company building 2020 bikes in 2015 is Pole bikes:

Here is their 29er with 140mm of travel and a wheelbase of 1314mm in size large and a headangle of 64.5 :
www.polebicycles.com/bicycles/mountain/enduro/evolink-140-en-29
  • 1 0
 I feel that Whyte has been quite progressive as well. I bought their g160 which has 635mm reach and 1200+ wheelbase in medium. It's 650b so maybe not relative to this discussion but the geometry is closer to geometron than anything else I've seen.
  • 3 0
 Did I miss it or is there no actual geometry chart? And can we get a test and in depth look at both, 27.5 and 29er bikes, please? I wish there were more tests on Nicolai bikes. I'd love to see how they compare against the big brands like Trek, Specialized, etc. Nicolai builds nice stuff, even though to some their bikes may not as pleasing to the eye as to others maybe...
  • 3 0
 Starting to really enjoy my long legged carbine 29, which is consider pretty aggro. Admittedly a little more of handful in the berms but I'm starting to adjust my riding style and I believe I'm quicker for it
  • 3 1
 This is a dream bike, the benefits far outweigh the drawbacks. Yes it might be a little harder to manouvere but 1) that's safer than it being twitchy in real rough terrain and 2) if you're a good rider you can bunny hop and manual any bike with any bb height and cs length. Just my $0.02
  • 4 2
 How about we all just ride our f*cking bikes.. What ever size wheels they have. Why do we as a Mt. Bike community have to follow the "Mine is better than yours" BS that society crams down our throats. ONE LOVE!! is all I have for this sport. Thought we were getting past all this wheel size shit!
  • 2 0
 so, just read every comment. And it was worth it. we all know there are an ever increasing number of AM 650b bikes in the bike parks of Ca / USA and Europe. Frankly... i would take my lapierre AM bike to the alps next season... not my 200mm old school DH bike. bottom line for me... whats the most fun on holiday?? i dunno... time will tell!
  • 3 1
 I've ridden the 650b and totally loved it. He's right I did shut up and just ride. Also went back to my enduro 29er which I thought was amazing after slackening the ha and lowering bb and thought it was skittery and nowhere near as nice to throw around. Would love to try the 29er version.
  • 4 0
 I'm loving all these articles! every time I refresh the page a new article shows up.
  • 8 3
 What do you mean no one has gone all in on 29ers yet? What about Niner?
  • 5 3
 And their XC-style lineup?
  • 10 2
 I think he meant that nobody really went all in with geometry of 29ers. I rode three Spec 29ers, two Konas and loved them, rode 2 Niners and they were straight dull.
  • 7 0
 doesn't niner mean "nineties geometry"? If not, it should
  • 1 0
 I'm a huge fan of chris and his thoughts of geomentry of longer/slacker but as far a the wheel size thoughts go i'm on the other side of the fence. I've got a banshee spitfire set in 26" wheels (though can go 27.5" and might do when things wear out) that i run a larger frame than i should do with short stem and in the slackest setting and a trek stache 29er that i will be plying with angler headsets with. Both bikes rock once set up correctly, there is a place for all wheel sizes, it really does just come down to what and where you ride.
  • 3 1
 A bike for the bike parks no less. I can't imagine this monster winding through tight, twisty single track. You might be able to pull it off, but itll be like taking a cruise ship to Venice.
  • 1 2
 How wrong you are. Just try it.
  • 3 1
 Well, simple physics would tell you it's not as maneuverable. It would simply be a different experience.
  • 3 2
 So Chris. You've designed another "custom" frame that you run your saddle slammed fully forward on?
M'kay...
Every product this guy has ever designed sells out despite their obvious flaws
There's genius at work somewhere here Wink
  • 5 0
 I own enduro 29. Best bike ever!!!!!
  • 7 3
 29ers rule all others drool!
  • 3 0
 here ya go; First Look: Canfield Brothers Riot - Pinkbike
www.pinkbike.com/news/canfield-brothers-riot.html
  • 4 2
 This is seat is mounted as close to the bar as possible. Maybe they should have made this bike a little shorter instead?:-)
  • 8 4
 you don't ride your bike down the mountain sitting down do you??
Just work your noggin' buddy
  • 4 0
 Implying it can't be ridden back up
  • 2 0
 Look at the seat position in the clamps on the seat post..
  • 1 0
 Maybe this one was built for bigger customer but it was just used for test/photoshoot?
  • 1 0
 It does look strange because the seat angle doesn't look that slack in order to force him to move his saddle that forward for pedaling efficiency. So if they moved the saddle that forward because the actual reach was too long than most probably this is an indication that they have created a bike that is actually too long! Anyway I would really like to ride such a bike to see how it handles overall because I am pretty sure that in a straight line it would handle quite well.
  • 2 0
 @ gpgalanis Believe me it feels totally normal when riding the bike.
  • 1 0
 Actually you are seeing the indication of a design tradeoff. The long top, tube long wheel base, shorter stem is based FISRT on the abjective of a bike descends and carries speed well. A good deal different than needeing pedaling efficiency first and foremost.
  • 4 2
 My first reaction was, "Banshee Phantom", but I did have several beers this evening. ????
  • 3 0
 Other than the color and wheelsize they are nothing alike.
  • 2 0
 So what SCU off set is fitted to that fork? was never quite sure real reason for more crown offset on 29er forks
  • 8 9
 This guys sounds like a giant f*cking douche bag.... The kinda guy who can smack the fun right out of mountain biking... Who in the f*ck builds a bike just to try and say "I told you so!"?? Maybe it's just how this article comes across but as of right now.. Chris is a douche bag until I am persuaded to believe otherwise... Lol
  • 1 0
 You're officially on his blacklist. He was obviously semi-joking
  • 3 1
 How about building a 26" to see if it works better than 650b and 29 and prove that 26 really ain't dead ????
  • 2 0
 Yeah, as a 6' 5" rider I really feel like this is a matter of opinion about the gyroscopic effect of a larger wheel.
  • 1 0
 Yup. 29" wheels on my XXL frame look the proper size, maybe even smaller in proportion to me than most riders on 27.5" wheels. Bring on the big rig, 29er, monster truck, trail destroyers!
  • 1 0
 @paulaston It's been almost a year now. Any follow up article or ride report for the GeoMetron 29?

Is ordering one as easy as contacting Mojo UK?
  • 2 1
 Would like to see this thing side by side with another 29er just to compare its size and geo
  • 5 3
 As a tall rider, this is the sickest thing ever!
  • 2 0
 Dang thumb, meant to give you props from another tall rider... I too am loving the trend towards long reach and wheelbase. Looks about right to me.
  • 2 1
 Nope. I don't care what the components or tech are, a 29er should not have that geo. Not at all.
  • 2 1
 more like GeometWrong. Look at that thing. Is that an XXL frame size? It looks horrid.
  • 1 0
 What are the travel numbers like?
  • 3 1
 Love my Following
  • 4 7
 " Specialized had a good stab at long legged big wheelers with the Enduro 29, then seemed to back off the offence as they put more effort into 650b and plus sized tire". After a full u turn on their ethos regarding 650b, one of many reasons I won't buy from the big S
  • 10 1
 They are just going where the money is. Makes business sense.
  • 2 1
 Is this article a bit tongue in cheek?
  • 2 1
 looks like a coupe with a big ass door
  • 1 0
 .. wow ! they look like nothing I've seen before ! ...
  • 1 0
 looks pretty dope actually
  • 1 0
 that saddle setback however....
  • 11 10
 Ugly
  • 1 1
 Can't you read, it's hugly not ugly!
  • 2 4
 That is not having a hug, it can have a slap for being ugly just like when the doctor slapped my mum for having an ugly child!
  • 4 4
 Long live the 26! At least until I can afford a new 27.5 rig.
  • 4 3
 Chris Porter is right.
  • 1 0
 lol wut
  • 2 1
 UGLY AS FUCK!!!
  • 4 5
 26, 27.5 or 29? Who fecking cares, just get out and ride.
  • 2 1
 I would but I got a 36er fat bike fir xmas and it's undrideabruh
  • 1 2
 Hmm, I think Niner is all in!
  • 6 8
 Tough to argue with his opinion of 29 inch wheels. Love this frame!
  • 3 4
 26 aint dead !
  • 5 2
 26" is not dead but is dying like the planet we live on
  • 6 8
 Sooo... ugly!!!
  • 6 1
 It's how it rides that counts. IMO it looks really good anyhow, is well engineered and the ride is amazing.
  • 4 7
 I'm going to ask for a 26 version to be made
  • 2 1
 this.
  • 2 6
flag poah (Dec 23, 2015 at 0:20) (Below Threshold)
 which dickfurs gave me negative props for wanting a 26 version built?
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