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View Full Version : New Axle Standard - Trek's Boost 148


Kirk Pacenti
10-06-2014, 02:00 PM
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
10-06-2014, 02:15 PM
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
10-06-2014, 03:54 PM
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
10-06-2014, 04:11 PM
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
10-06-2014, 04:22 PM
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
10-06-2014, 05:03 PM
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
10-06-2014, 05:07 PM
more cheap normal frames on ebay, awesome

mgm777
10-06-2014, 05:39 PM
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
10-07-2014, 09:49 AM
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
10-07-2014, 10:09 AM
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
10-07-2014, 10:52 AM
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
10-07-2014, 11:43 AM
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
10-07-2014, 12:03 PM
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
10-07-2014, 12:10 PM
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
10-07-2014, 12:42 PM
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.

ergott
10-07-2014, 12:48 PM
Shimano hub is pretty good considering it accommodates 11 speed and a disc in 135mm spacing. The 142 standard doesn't improve flange spacing since it just extends the axle into a lip of the frame. According to the video, the wider Trek spacing was utilized by making a wider hub shell increasing the bracing angle on both sides.

29in wheels are more susceptible to lateral flex than 26in wheels since the triangle made between the hub shell flanges and the rim is taller.

I must say that there is a lot more lateral flex in a 2+ inch tire than any wheel. It doesn't mean that things can't be improved, but worth noting.

ultraman6970
10-07-2014, 12:56 PM
148? pfffff... looks like wont even move to 11 speed now. No sense.

Good news that a lot of used good bikes will hit the market when the idea hits road bikes.

Wonder how they will sell the idea to the public.

Kirk Pacenti
10-07-2014, 01:39 PM
Shimano hub is pretty good considering it accommodates 11 speed and a disc in 135mm spacing. The 142 standard doesn't improve flange spacing since it just extends the axle into a lip of the frame. According to the video, the wider Trek spacing was utilized by making a wider hub shell increasing the bracing angle on both sides.

29in wheels are more susceptible to lateral flex than 26in wheels since the triangle made between the hub shell flanges and the rim is taller.

I must say that there is a lot more lateral flex in a 2+ inch tire than any wheel. It doesn't mean that things can't be improved, but worth noting.


Your touching on why I like the concept so much. All the improvements mentioned are incremental, but moving towards optimization. Better bracing angle / less dish, more balanced spoke tensions, are all worth while reasons to move in this direction. Combining the new hub specs with an asym rim will make it that much better.

The fact that you can get better tire clearance and *shorten chainstays* is just icing on the cake for me.




*not always a worthy goal.*

Cheers,
KP

oldpotatoe
10-07-2014, 06:10 PM
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.

Yes but we're able to move the LH flange outboard, a good thing, and still have room for the rotor. 130 disc rears can be downright scary.

steveandbarb1
10-07-2014, 06:58 PM
V brakes are obsolete?
Oh well...

bluesea
10-07-2014, 07:16 PM
Yes but we're able to move the LH flange outboard, a good thing, and still have room for the rotor. 130 disc rears can be downright scary.


Right, but what about dish?

Mikej
10-07-2014, 07:41 PM
Yeah, remember, 2.3" tires at 22 psi will be squishy, no matter how wide the spacing.

thirdgenbird
10-07-2014, 07:58 PM
The industry has essentially reengineered/changed the following parts in the effort to make up for the move to 29in wheels.

Rear hub (wider to make up for stiffness loss)
Crankset/spider (wider chainline to accommodate hub and increased tire size)
Stem (shorter and negative rise to make up for head tube height)
Bars (wider for better leverage)

The disappointing thing is that it all appears to be more of a "return to zero" rather than an actual improvement. The same changes made to a 26in (or maybe even a 650b) bike would have meant stronger wheels, more tire clearance, and better handling vs trying to get things back where they were.

Charles M
10-07-2014, 08:14 PM
Your touching on why I like the concept so much. All the improvements mentioned are incremental, but moving towards optimization. Better bracing angle / less dish, more balanced spoke tensions, are all worth while reasons to move in this direction. Combining the new hub specs with an asym rim will make it that much better.

The fact that you can get better tire clearance and *shorten chainstays* is just icing on the cake for me.




*not always a worthy goal.*

Cheers,
KP

Yeah, I like this... I run a little narrower tire and don't drop the pressure as much as some friends do and I think part of that is I prefer the tighter feel. I like the feel and push more up against breaking traction versus allowing the rubber to move around more on what ever surface I'm on... I would rather stiffer wheels too.

Maybe that's a personal thing (and if I'm just tooling around, I don't care at all either way). But I like doing this for 29 MTB.

oldpotatoe
10-07-2014, 08:39 PM
Right, but what about dish?

I'm comparing a 130mm rear without a rotor and then add a rotor, gotta move the LH flange way in(bad). A 'fix' is 135mm that when with a rotor, the LH flange us about the same place as 130mm w/o a rotor.

bluesea
10-07-2014, 08:56 PM
The industry has essentially reengineered/changed the following parts in the effort to make up for the move to 29in wheels.

Rear hub (wider to make up for stiffness loss)
Crankset/spider (wider chainline to accommodate hub and increased tire size)
Stem (shorter and negative rise to make up for head tube height)
Bars (wider for better leverage)

The disappointing thing is that it all appears to be more of a "return to zero" rather than an actual improvement. The same changes made to a 26in (or maybe even a 650b) bike would have meant stronger wheels, more tire clearance, and better handling vs trying to get things back where they were.


Yup.

54ny77
10-07-2014, 09:02 PM
I'm waiting for 154.75 before I adopt change.

Netdewt
10-07-2014, 09:35 PM
This is great. Hey I know, let's make mobile phones too big to hand hold or fit in our pocket, while were at it.

avalonracing
10-07-2014, 09:59 PM
The industry has essentially reengineered/changed the following parts in the effort to make up for the move to 29in wheels.

Rear hub (wider to make up for stiffness loss)
Crankset/spider (wider chainline to accommodate hub and increased tire size)
Stem (shorter and negative rise to make up for head tube height)
Bars (wider for better leverage)

The disappointing thing is that it all appears to be more of a "return to zero" rather than an actual improvement. The same changes made to a 26in (or maybe even a 650b) bike would have meant stronger wheels, more tire clearance, and better handling vs trying to get things back where they were.

Great post!

avalonracing
10-07-2014, 10:02 PM
This is great. Hey I know, let's make mobile phones too big to hand hold or fit in our pocket, while were at it.

Yes, we need bigger phones and then they'll re-engineer bigger pockets for the phones and then to accommodate the bigger pockets we'll need to bring back pleats but now they'll be super-pleats but work right with that you'll need a bigger jacket and soon all the cool kids will be wearing zoot-suits.

ceolwulf
10-07-2014, 10:06 PM
I'm waiting for 154.75 before I adopt change.

I hear that is planned for the upcoming 28.375 wheel size standard.

54ny77
10-07-2014, 10:27 PM
http://i191.photobucket.com/albums/z113/jpmz06/zootsuitjpg_zps04ce10f5.png (http://s191.photobucket.com/user/jpmz06/media/zootsuitjpg_zps04ce10f5.png.html)

Yes, we need bigger phones and then they'll re-engineer bigger pockets for the phones and then to accommodate the bigger pockets we'll need to bring back pleats but now they'll be super-pleats but work right with that you'll need a bigger jacket and soon all the cool kids will be wearing zoot-suits.

Kirk Pacenti
10-07-2014, 10:33 PM
The disappointing thing is that it all appears to be more of a "return to zero" rather than an actual improvement. The same changes made to a 26in (or maybe even a 650b) bike would have meant stronger wheels, more tire clearance, and better handling vs trying to get things back where they were.



If you watch https://www.youtube.com/watch?v=xauVb0sAgM4 and believe the numbers (0:45 - 1:05), doing the same for a 650b (27.5") wheel would be stiffer than a traditional 26" wheel.


Cheers,
KP

Netdewt
10-07-2014, 10:39 PM
Is everything going to keep getting bigger until "classic" sizing is reintroduced again someday? Sort of like how the BMW 3 series bloated until it was no longer a compact car, so they had to release the 1?

avalonracing
10-07-2014, 10:48 PM
Without ever riding a 27.5" I still believe that is they way it should have gone (and may still go).

My 29" is sweet but I doesn't handle the way my 26" MTBs do and it really isn't as fun. I have a feeling that 650b is probably the performance/fun sweet spot.

thirdgenbird
10-07-2014, 10:48 PM
^ This is (among many other frame geometry issues) what inspired me to develop 27.5" wheels in late 2006.


If you watch https://www.youtube.com/watch?v=xauVb0sAgM4 and believe the numbers (0:45 - 1:05), doing the same for a 650b (27.5") wheel would be stiffer than a traditional 26" wheel.


Cheers,
KP

It makes sense. When I grow tired of my 26in bike, I will move to 650b. In still disappointed I didn't have room to convert. It would be very tight.

For now, the 26 is a blast.

Mikej
10-08-2014, 07:38 AM
[QUOTE=thirdgenbird;1635195]The industry has essentially reengineered/changed the following parts in the effort to make up for the move to 29in wheels.

Rear hub (wider to make up for stiffness loss)
Crankset/spider (wider chainline to accommodate hub and increased tire size)
Stem (shorter and negative rise to make up for head tube height)
Bars (wider for better leverage)

None of those are even correct or make sense - Chain line is not changed, rear hub is still the same and working fine, shorter stem with negative rise feels fine to me (also, its stack height, ht length are shorter on 29ers), wider bars and better leverage? gimme some.

Its just something to sell, that guy in the video has a job to sell us stuff, need it or not. But I am 100% on board with 29er's and will never look back.

avalonracing
10-08-2014, 08:04 AM
I have a 29 with reasonably sized handlebars and I've never understood this, "You need huge bars for more leverage" thing. Can anyone explain this to me?
It doesn't require any more force to turn the bars and you still need to clear the trees on narrow single track (at least where I live). I've seen some of my buddies clip trees with their giant bars and bite it.

Niner was doing a demo day at my local trails and the bikes had 780mm bars on Medium and Small MTBs!

I know the bars can be cut down and it's more of the one size fits all approach but why would anyone who isn't 7'6" with a 58" chest need 780mm bars "for leverage". And even then, it doesn't require leverage to turn the bars, it's just about fit.

Please explain / discuss-

thirdgenbird
10-08-2014, 08:33 AM
None of those are even correct or make sense - Chain line is not changed, rear hub is still the same and working fine, shorter stem with negative rise feels fine to me (also, its stack height, ht length are shorter on 29ers), wider bars and better leverage? gimme some.

Its just something to sell, that guy in the video has a job to sell us stuff, need it or not. But I am 100% on board with 29er's and will never look back.

It's obvious you didn't watch the video or know what you are talking about.

The 148 hub has wider flange spacing to make a 29in wheel as strong as a 26 in wheel and as a result, the cassette is placed further out. This makes the chainline wider and results in needing a new crankset or spider.

Negative rise will absolutely feel fine. That's the whole point, it was needed to get bars back down to the same height as a 26in bike. It's not a problem, but it is one more thing that was needed to make 29in wheels work.

oldpotatoe
10-08-2014, 08:41 AM
If you watch https://www.youtube.com/watch?v=xauVb0sAgM4 and believe the numbers (0:45 - 1:05), doing the same for a 650b (27.5") wheel would be stiffer than a traditional 26" wheel.


Cheers,
KP

No doubt but like so much 'bike', it implies that a 26inch or whatever wheel, NOT using another 'standard', is weak, sloppy, flexy..and that's not true. It is for poorly designed wheels but you can around that rather than create another 'standard'(dislike that word as much as 'bomb proof' and 'boat anchor').

"These alloy chainring bolts are so much lighter!!!", but steel ones aren't heavy.

Kirk Pacenti
10-08-2014, 08:56 AM
No doubt but like so much 'bike', it implies that a 26inch or whatever wheel, NOT using another 'standard', is weak, sloppy, flexy..and that's not true. It is for poorly designed wheels but you can around that rather than create another 'standard'(dislike that word as much as 'bomb proff and boat anchor).

"These alloy chainring bolts are so much lighter!!!", but steel ones aren't heavy.

In general I would agree with this statement - and specifically why I said "traditional 26" wheel". That said the current 135/142/10spd/disc standard, leaves a lot to be desired from a design standpoint (imo), even for a 26" wheel.

Some guys here get hung up on Q-factor, others on chainline, for me it's wheel dish. I am pretty OCD about doing anything within reason (I think the 148 design is reasonable) that will reduce dish and improve bracing angles.


It might also be helpful to keep in mind that 142 TA hub is geometrically equivalent to a 135 QR hub. Likewise the new 148 TA hub is theoretically equal to a 141 QR hub. That's not very radical in my view. Remember in the early 90's when WTB frames / hubs had their own standard, using a 140 OLD? I had a set of those hubs and even built a frame around them. For the life of me, I couldn't understand why every frame maker didn't adopt that spec. Looks like we're finally getting there.

Cheers,
KP

oldpotatoe
10-08-2014, 09:15 AM
In general I would agree with this statement - and specifically why I said "traditional 26" wheel". That said the current 135/142/10spd/disc standard, leaves a lot to be desired from a design standpoint (imo), even for a 26" wheel.

Some guys here get hung up on Q-factor, others on chainline, for me it's wheel dish. I am pretty OCD about doing anything within reason (I think the 148 design is reasonable) that will bring some symmetry to rear wheels.

It might also be helpful to keep in mind that 142 TA hub is geometrically equivalent to a 135 QR hub. Likewise the new 148 TA hub is what would be the same as a 141 QR hub. That's not very radical in my view. Remember in the early 90's when WTB frames / hubs had their own standard 140 OLD? I had a set of those and for the life of my couldn't understand why every frame maker didn't adopt that spec...???

Cheers,
KP

I agree...back to the days of symmetric hubs..

I don't disagree that wider flanges, particularly with a rotor', makes a 'better' wheel. Then some of these production idiots could slap that very thin spoke, low spoke count, light rim, onto those OEM bikes and see a modicum of reliabiity. Some of the wheels that came on Spec-Ed 29ers(and others), OE, were downright stoopid..

But like BBs, standard this is not. I suspect that unless trek has a way to copywrite/patent this, it probably will become some sort of 'standard'...

BUT TA on a road bike? tapered forks? maybe when the disc brake silliness takes hold(and it will, unfortunately) but it just gets more complicated(read>$$)...for no real performance advantage for that enthusiast on his Sunday 30 miler up to Lyons and back..

Kirk Pacenti
10-08-2014, 09:24 AM
I agree...back to the days of symmetric hubs..

I don't disagree that wider flanges, particularly with a rotor', makes a 'better' wheel. Then some of these production idiots could slap that very thin spoke, low spoke count, light rim, onto those OEM bikes and see a modicum of reliabiity. Some of the wheels that came on Spec-Ed 29ers(and others), OE, were downright stoopid..

But like BBs, standard this is not. I suspect that unless trek has a way to copywrite/patent this, it probably will become some sort of 'standard'...

BUT TA on a road bike? tapered forks? maybe when the disc brake silliness takes hold(and it will, unfortunately) but it just gets more complicated(read>$$)...for no real performance advantage for that enthusiast on his Sunday 30 miler up to Lyons and back..

As far as I know the 148 design is open source. I've already heard about other smaller frame and hub brands scrambling to adopt the design in time for 2105 production.

JAGI410
10-08-2014, 09:45 AM
Now that Fatbikes have gone from 135, to 170, to 177, to 190, and now 197 in the rear over the past 4 years, I'd be waiting a while to abandon 135 on my mountain bike for a new "standard". As us Fatbikers have learned, there's no such thing as "standard", and most of it is just marketing. 6psi in a 4.8" tire on a 100mm rim, yet they tout "stiffness". Riiiggggghhhhttt.

bingomck
07-23-2015, 11:33 AM
Now that Boost is out in the wild... Anyone with direct experience? Looking at a New mtb and figure I might as well go with latest and greatest, although it seems 2017 year models it will be more Widely adapted across models.

Mikej
07-23-2015, 01:20 PM
ok - I was incorrect about the chain line - I typed before watching video -so I shall continue with my MO - that rim "stiffness" is with out tires I presume - so once I add my tubeless Ralphs at 23 psi, I bet its a wash ----

tumbler
07-23-2015, 01:52 PM
I'm so confused by all of this. I hope my bike still works when I take it out later today.

bicycletricycle
07-23-2015, 02:38 PM
I cant believe we have all made it so far with punny QR axles. It seems like they could just rip out at any time, and all that frame flex, its amazing we are not thrown from our bicycle around every turn. I am so glad someone is solving these urgent problem.

on a more serious note.

less dish is a good thing, as much talk about Q factor as there is I don't know if it is actually a real concern for many people.

Butch
07-23-2015, 04:13 PM
I'm with Kirk, 100% behind this. Back in the day this is why we (at Co-Motion) worked with other tandem builders and hub makers to make the tandem standard 145. The difference in wheel strength and stiffness is huge when the dish is gone, or nearly gone and the flanges are wider. We have been riding Boost 148 bikes here since we showed one at NAHBS and it makes a big difference there as well. The tire clearance is sure nice with the big tires coming on the market and the wheel is stiffer.
butch@moots

Gummee
07-23-2015, 10:03 PM
My 29" is sweet but I doesn't handle the way my 26" MTBs do and it really isn't as fun. I have a feeling that 650b is probably the performance/fun sweet spot.I rode 26ers for so many years that when it came time to upgrade, I went P650b.

...then I got talked into building a 29er for racing.

Surprisingly enough, I'm finding myself liking my 29er. Rides like a bike, not a freight train.

I think I'm gonna ride the Ritchey again tomorrow nite 'cause I haven't ridden it in a month or so.

M

stephenmarklay
07-23-2015, 10:22 PM
Yeah its hard to keep up. I am about to get a 29er hardtail. I guess I don稚 really care as long as the bike is fun. In this case its a Salsa El Mariachi with a 135 rear. I guess if it is laterally weak I could run an OCR rim. When I am riding I don稚 care what standard it has.

Until recently I was riding 7 speed down tube shifters on my road bike and it was fun.

bcroslin
07-23-2015, 10:34 PM
Retrogrouches annoy me but I think I'm starting to become one. Seems like every week there's a new BB standard, thru axel standard, etc. I've gotten really cynical lately about this stuff and it seems to me every one of these new standards is just a reason to make people think they need a new bike.

DrSpoke
07-24-2015, 12:57 AM
Now that Boost is out in the wild... Anyone with direct experience? Looking at a New mtb and figure I might as well go with latest and greatest, although it seems 2017 year models it will be more Widely adapted across models.

No direct experience but I've been riding a Pivot Mach429 Carbon for almost 2 years now - best bike I've ever had. And I have a lot of respect for Chris Cocalis at Pivot. They just released a new Mach429 Trail with boost front and rear. In addition, with the added tire clearance you can run 27.5+ wheels w/tires up to 2.8". They've been on a roll lately w/new models and this one looks like another home run.

I'm pretty much in agreement with Kirk Pacenti on this one. It seems that both road and mountain bikes are in a constant state of evolution - pretty much like every other product out there in the market from cars to motorcycles to computers to cameras to washing machines. But it does seem like around here for every new idea the response falls into 3 camps with 2 being mostly negative - that is about 50% are the retros and say it's not necessary and that what I have now works fine, another 35% react with an auto response by saying it's a marketing gimmick no matter what it is and whether or not they've really studied it, understand it, or use it, and then there is the other 15% that embrace it. I suppose some of these ideas are marketing gimmicks but I think most are a solution to a problem or at least an attempt to improve current solutions. And sometimes new ideas become standards and sometimes they fall by the wayside. When I say that I think of all the Rube Goldberg mountain bike suspension designs in the 90s before they figured it all out and settled on a few basic designs that actually work.

I think that every individual improvement doesn't add that much. But over a 5 or 10 year period, or longer, the differences are huge. In 2002 I went from a '76 Alan/Nuovo Record 2x6 friction to a Serotta Concours w/Daytona 2x10 indexed. Needless to say the difference was huge. Also in 2002 I went from a '96 Bontrager steel hardtail to a Santa Cruz full suspension and again the difference was huge, especially the fork, and that was only about a 6 year difference. And then in 2013 I went from the 2002 Santa Cruz Superlight single pivot suspension w/26" wheels, 3x9 drivetrain and V-brakes to the Pivot w/carbon frame, DW-Link suspension, 29" wheels, 2x10 drivetrain and hydraulic discs. Again a huge difference over about 10 years. Necessary? Probably not, but I'm not going back and can't wait to see what's next. I must say, modern 29ers are dialed.

http://www.pivotcycles.com/bike/mach-429-trail/