Thus far, Pivot is the only one making trail mountain bikes with a 157mm rear axle standard, calling it Super Boost. Now, Canadian MTB brand Knolly is about to join them with their new 157TRAIL design. Having held off of regular 148mm Boost axle spacing, they say this wider format gives them more tire size options, better suspension design profiles, and zero crank or Q-factor compromises.

Knolly Fugitive 29er mountain bike introduces new 157TRAIL rear axle spacingQuick background: 157mm hubs have been used for Downhill for ages, so it’s not a new standard. What’s relatively new is the combination of that hub standard with regular mountain bikes. And wheel brands like Industry Nine (among others, including custom wheelbuilders) can easily lace up the appropriate hub to whatever rim you want.

Knolly is using the extra width at the back to make their bikes ready for anything from 29×2.6 to 27.5×3.25. So you can choose the right wheel and tire combo for the day, without (they say) affecting BB height. They say the extra hub flange spacing width provides a massive 31% increase in lateral stiffness, too, so the wheels themselves get better.

Knolly Fugitive 29er mountain bike introduces new 157TRAIL rear axle spacing

Blue shows standard Boost chainstay width, gray is 157TRAIL. (all photos from Knolly)

Other than that, fit and finish stay the same. They’re even able to keep a short 16.95″ (430.5mm) chainstay length. And chainstay width only spreads by 1.5mm, so heel clearance is still good, letting it work with narrow Q-factor cranks like the Race Face Next SL in a regular threaded 73mm BB shell.

The nearly universal move to wide-range 1x drivetrains helps make this happen. While Knolly says their design is front derailleur compatible, appearances suggest it’s single-ring optimized. The numbers say it’ll fit up to a 36-tooth single ring on 29er builds, and 38-tooth rings with 27.5″ tires.


sneak peek of 2018 Knolly Fugitive 29er trail mountain bikeThe first bike to get their new 157TRAIL design is the upcoming Knolly Fugitive 29er, which will be their first 29er mountain bike, too. Coming this spring, it’ll be a 120mm travel trail bike designed with 120-140mm forks in mind. Head angle is around 66º (+/- depending on fork travel). More info as we get it.


  1. caliente on

    Gross. What makes me upset is that to make these changes, the hub manufacturers have to be on board as well. This hurts consumers, small bike builders, small bike and components companies, as well as the local bike shops who will have to dump inventory to keep up with the newest “standards”. We all are here because we want new stuff, but nothing was wrong with 142. Or even 148. When 165 is the new standard, I’ll write the same thing.

    • JNH on

      157mm has been around longer than 148×12. In fact it’s a different end cap for the 150×12 spacing so there are literally two decades worth of inventory for this standard already out there. Of course this is the reason the major OEMs went and invented 148×12, they can’t sell you expensive incremental upgrades if the parts are already available. Pivot and Knolly have the right idea, it’s the brands pushing a second best solution that just so happens not to work with the existing standards that need your ire.

    • Michael Myers on

      You’re wrong. Nobody is taking a slim dime from your pocket for anything 157mm, unless you want to be on the very latest and greatest.

      I have a couple of 135mm bikes that are still going strong. One has v-brakes, and still gets ridden on occasion.

      Guess what? It still works.

  2. fitness on

    Weird, not as many wheels or hubs will be available for this. At least with the recently bashed Dub cranks changing things around you just need a crank and a BB and you can fit on and improve 99% of bikes already in existence

  3. ascarlarkinyar on

    Ridiculous that manufacturers think they can fool us with “its 10%stiffer, so buy it and make every other bike obsolete. ” if all these claims of stiffer were true my bike would have shattered like thin ice by now….

  4. Hhh on

    I’m not buying it… figuratively and literally. The truth is not many riders actually need any of this stuff. The bike industry is so shameless & wack !

    • Michael Myers on

      I don’t NEED anything other than a rigid single speed to ride single track. Everything else is superfluous.

      Do you currently ride with things you don’t need?

  5. Antipodean G on

    I have 4 bikes, all 26 (yea, I’m old skool but they are all still rocking bikes). Two run 135 x 10mm, one runs 135 9mm QR and the other 142×12. The one with the most ‘issues’ is the 142, it constantly comes loose and is just a PIA. The 135×10 (especially with the DT axle) are rock solid on the FS backends, and plenty stiff for me @ 95kg ride weight. I honestly have a hard time telling any difference in any of them. Sure, I’m not doing gaps, big drops are the like but at 6’3″ and around 95kg ride weight, is there was flex, I’d sure as hell notice it.

    I’m all for progress but this sort of stuff falls well into the ‘stupidity’ sector and I agree with the comments that it’s just part of a cash grab in an industry that’s struggling to truly innovate or do something of realistic worth for its customer base.

  6. Ol' SHel' on

    157 actually makes sense. It centers the cassette on a normal 50mm chainline, and gives symmetrical spoke flanges for a more durable wheel. It should have become the standard about 15 years ago.

    The problem is that as soon as you buy 157, Sram will go to a 15-speed cassette that requires a new hub shell, pushes the spoke flanges back into a bad position, and forces you to buy another new wheel in order to stay hip.

    Get ready. This industry isn’t growing in the number of users, so they’re introducing more incompatible ‘standards’ to try to get you to buy more product.

  7. Me on

    Cool, I really enjoy the way i strike my heels on my new boost frame. Can’t wait to get one of these so I can do it even more!

  8. dustytires on

    Mondraker had super boost first. They also had long TT before anyone else thanks to Cesar Rojo.
    I know this is a US site, but, Mondraker kicked Pivot and Knolly axles almost 3 years ago. I bought a frame to build up, easily found a 157 rear hub as they have been around for many many years and bam, wheel done. I have no idea why all the whining about all the new standards. Build out your frames the first time with good kit and you won’t need more shit to replace the stock shit that your package deal bike came with. Rebuild good kit instead of just replacing worn shit. duh.

  9. VeloFreak on

    LOL! My newest mountainbike is from 2005, lots of components changed couple times, but with things like this, I can just keep waiting more and more to decide what new bike to buy me. Been like this for the last 7 years… money in the pocket is never a problem.

  10. Bewer on

    This is just another evidance that the bike industry is completely crazy. A few guys believe to enrich the world with new „standards“ every month. What is the benefit for the customers exzeptionell beeing completely confuded. And do this few guys think that the bike wheel industry is waiting for that to change their moulds just to follow one single noun?

  11. Zoso on

    Most of you need to think before your knee-jerk reaction is spewed forth. If you didn’t think Boost148 was a temporary thing, you probably didn’t think through the issue that much. 157 makes perfect sense. The problem is not 157, the problem was not going to 157 and skipping 148 all together in the first place.

    • Bewer on

      It´s really ridiculous! You can surly tell me the market share of the Boost148 or the 157 in comparison of the whole MTB market. So what we are talking about? That´s not relevant for the. customers. Axle standards will never be the main argument for the majority of the normal customers buying a new bike. It´s more a fact for a small group of bikers looking always for something new. But only to be new is not equal to a moneymaker. Just to satisfy the wise-guys.

    • Antipodean G on

      @Zoso “Most of you need to think before your knee-jerk reaction is spewed forth. If you didn’t think Boost148 was a temporary thing, you probably didn’t think through the issue that much.”

      Ummm, really? So the consumer now has to do the thinking for the industry? Or more to the point, by your reasoning the ‘industry’ willingly and knowingly made people invest in something that was only ever going to be a stopgap until they could sort themselves out?

      Yes, and D.J.T was a sane choice for a world leader…..

      All this ‘stuff’ is just a marketing and bike-nerd w@#!. I challenge any ‘weekend’ rider to tell me the difference between the same modern bike with a 148, 157, whatever vs. a 135x10mm QR. If they can, they should be hired for product development testing.

      It’s all a placebo, 98% of the time people *think* they feel the difference because they are told there is one.


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