New Axle Standard - Trek's Boost 148

[Kirk Pacenti]

I will go on the record here and now and say that I am 100% behind it.

https://www.youtube.com/watch?v=3wg_E_VuIg4

Cheers,
KP

[vqdriver]

it's getting close to the point it makes no sense to shop for a new frameset anymore. by the time i get a compatible fork and wheelset, it costs about as much to just buy a new bike. but maybe that's the point. i've no input as to whether this is good or not, but it sure is a moving target.

and btw, is it called a 'standard' if you're the only one using it? i thought that was called 'proprietary'

[Mark McM]

Swell. Another new standard which increases pedaling q-factor. As our BBs get wider, and our hubs get wider, little concern has been given to the fact that our pedal stance (Q-factor) is also getting wider.

In addition to the comfort factor (I, in particular prefer as narrow a Q as I can get), it's been shown that wider Q factors are less efficient than narrower:

http://www.ncbi.nlm.nih.gov/pubmed/22612455

[oldpotatoe]

They said all the right words, 'lighter', 'stiffer' and erroneous 'standard'.

I like the 'super intrigued' comment but if it's 650b, does that mean 145.5 rear axle? Also the bearded guy asked what problem are they trying to solve....no answer there.

It may be the greatest idea ever but it smacks of trek trying to control the mtb world with another proprietary gizmo.

[Mikej]

Well, the 142 mm is not any wider than the 135 mm. I would think a 29er would benefit from a wider axle, is it really going to affect the q? Does it matter?

[David Tollefson]

Chainline... Seems to me you could run a double using a current triple and just ditch the small ring and accomplish the same thing.

[bicycletricycle]

more cheap normal frames on ebay, awesome

[mgm777]

Originally Posted by Mark McM

Swell. Another new standard which increases pedaling q-factor. As our BBs get wider, and our hubs get wider, little concern has been given to the fact that our pedal stance (Q-factor) is also getting wider.

In addition to the comfort factor (I, in particular prefer as narrow a Q as I can get), it's been shown that wider Q factors are less efficient than narrower:

http://www.ncbi.nlm.nih.gov/pubmed/22612455

In the video, the Trek designer said the new width, 148, won't affect Q factor. He said it would remain the same.

[Mark McM]

Originally Posted by mgm777

In the video, the Trek designer said the new width, 148, won't affect Q factor. He said it would remain the same.

If so, it can only be because the cranks are already mis-designed, and have a wider Q than necessary. Even with traditional axle widths, cranks are made with a variety of Q widths, many with Q widths wider than necessary. Increasing axle width only means that they no longer have the ability to fix prior Q width mistakes.

[Mikej]

Originally Posted by Mark McM

Swell. Another new standard which increases pedaling q-factor. As our BBs get wider, and our hubs get wider, little concern has been given to the fact that our pedal stance (Q-factor) is also getting wider.

In addition to the comfort factor (I, in particular prefer as narrow a Q as I can get), it's been shown that wider Q factors are less efficient than narrower:

http://www.ncbi.nlm.nih.gov/pubmed/22612455

That study just shows that the test subjects were not conditioned to the multiple q-factors provided

[ergott]

I'm pretty sure Q isn't increased because it's a single ring setup instead of double or triple. If dropping rings I can see how you can do this without increasing Q

[Kirk Pacenti]

If you watched the video you'd see (starting around minute 1:20) that the offset was achieved in the spider. The crank arms remain exactly where they were, but the spider moves to the right along with the hub, keeping the chainline intact. Q-factor remains unchanged.

They started with 29ers, because that's where it's needed most, rest assured it will trickle down to all wheel sizes.

Cheers,
KP

[firerescuefin]

Originally Posted by Kirk Pacenti

They started with 29ers, because that's where it's needed most.

Cheers,
KP

KP.....When you've got time, can you give the dumb'd down reason why its needed/the benefit it will provide.

[Mark McM]

Originally Posted by Mikej

That study just shows that the test subjects were not conditioned to the multiple q-factors provided

Actually, it's really the other way around - they benefitted from narrower Q despite not having time to be conditioned to them.

Modern road bike crank Q widths vary from about 145 mm for the vary narrowest, to up to about 160 mm for the widest. MTB Q factors are typically wider still. Since the study's test subject were all experienced cyclists, it is likely that they have been conditioned to Q factors in the range of 150 mm to 170 mm or so. And yet, the study found the maximum efficiencies were with Q factors of 90 mm and 120 mm - narrower than found on any of today's cranks.

[bluesea]

Even more than road bikes 29ers benefit from wider bracing angles, which this standard purports to deliver.


Now the newish Shimano 135 road disc hubs, correct me if I'm wrong, failed in this respect because they kept the freehub located in the same place as 130.