Hello Vital MTB Visitor,
We’re conducting a survey and would appreciate your input. Your answers will help Vital and the MTB industry better understand what riders like you want. Survey results will be used to recognize top brands. Make your voice heard!
Five lucky people will be selected at random to win a Vital MTB t-shirt.
Thanks in advance,
The Vital MTB Crew
This looks like a good way to get rid of the vulnerable pull link that was hanging out under the BB on the last version of the Demo prototype. But I'm surprised to hear it has "pretty high anti-rise," and I'm also curious what numbers you think are pretty high, aka above or below 100%
Specialized has been on the very very low AR program for a long time, in the 40-60% range on the Demo, Enduro, and Stumpjumper for years and years. I would be shocked if they went above 100% on the new Demo, and that would represent a big change in suspension philosophy for them.
As somebody who's tested this variable back to back on the same chassis (not two totally different forks), the juice wasn't worth the squeeze.
Maybe we need to do a fork stiffness deep dive like the excellent frame compliance analysis Burney did. But in short, forks also have roll and wag. Everyone usually thinks of only wag and they test it with the wheel between the legs, but I'd argue this is only a valid indicator of stiffness during full braking on dry pavement. In this situation, the hex axle can offer a small benefit in reducing wag, but in actual on trail braking the wag isn't as severe and therefore the benefits didn't out weight the complexity of that design.
If we really want to have a conversation about on trail stiffness and compliance of modern USD forks, roll would really be the focus.
Starting between 60-80, but without a measuring tape, some callipers and the bike in hand I'm afraid it's just my guess. I keep churning results of about 40-50% progression out which can't be right either.
Yes, the more cogs and chains you include, the more efficiency loss. IIRC the lion’s share of efficiency losses in a chain-drive are from internal friction in the rollers in the chain as they spin under a torque load as they initially contact and then release from the teeth on chainring and cassette. The more load-bearing chains and cogs you have, the more friction. So we're in agreement on that.
But, as you pointed out, there’s also a lot of friction in a chain-drive multi-gear drivetrain from cross-chaining at an angle, which is especially egregious on a modern 1x12 drivetrain. The chain has to do some crazy stuff to get from a 32 tooth chainring (and 55mm chainline, which positions the chainring extra far outboard) and then get all the way back to a 12-speed 52 tooth cog that’s super inboard.
And, as always, in a sealed environment you can also count on consistent lubrication without external contamination, which counts for a lot in mountain biking. I don't know if the new Praxis gearbox will actually work in reality, if it's reliable or efficient but, to my eyes, it's the first plausible gearbox design I've seen.
In theory, if your pinch bolts don't ever slip then the torsional rigidity added by the axle would be a function of OD and ID. All the hex buys you is the assurance that it can never slip.
https://www.megamo.com/de/e-bike/e-mountainbike-fully/reason/reason-crb-01-(26)
New XT on this BIke. Bike itself looks interesting- never heard of them.
Ecclesiastes 1:9
https://www.vitalmtb.com/forums/The-Hub,2/Are-Upside-Down-forks-really-flexy,11099
100%
more than an USD, the exact behavior is what makes them generate more grip while braking and thus braking fast while the suspension is still working instead of binding
Forgot about that and props to Primoz, it is an insightful post. However, it is only looking at wag and not roll. If he did include roll, I'd venture to guess the results would be similar though, the USD is not as stiff as a RSD. But the nuance of the whole game is what is the right amount of flex/stiffness/compliance?
Cane creek joins the upside down party.
Floating bushings in this one perhaps??
With a 15mm hex axle.
To me it looks like the foam model of whats probably going to be the next Enduro, rather than this high pivot.
What will be interesting is how they try to ebike that design- neither yours, the foam model, or the patent fillings have enough room for a motor.
This one looked like a motor was possible.
No chance they are 5DEV, Loic wants to get to the end of a run with 2 crank arms!
Yes yes yes!!!
Finally some movement on the new Enduro! Maybe it’s not too far away. Spesh always strategically place some Easter eggs in their videos, nice catch!
The foam mockup reminds me of a skid steer arm haha
![]()
Yeah, gonna be a big shock tunnel for an enduro bike, that's he first thing spec should improve.
They axle isn't really in torsion though (that would be both legs rotating opposite way around the hub) so I'm not sure how helpful is? A 20mm axle or maybe torque caps are probably the better options out of what already exists
Turner back in the FS game?!
I don't think the Spesh team leaves that much to chance.
Essentially an aluminum Pivot frame with hopefully non super boost. If it turns out to be cheaper, they will sell heaps most likely. At least in my thinking
Definitely a Ti front triangle given the rest of the Turner range. I love DT’s design ethos, so I’m intrigued.
There is a component of torsion and a component of bending. For the wheel be misaligned with the bars/stem, one fork leg has to be angled forward/backward (however you chose to view it) relative to the other. An easy way to visualize this is hold a bar straight out in front of you firmly holding one end with each hand and try and pull one hand down. Then do the same thing but with one hand very loosely holding the bar. It becomes much easier to lower the one hand and the bar will rotate slightly in the hand with a looser grip.
The big question regarding all these new USD forks is, where are we putting the mudguard?
@iceman2058's 2nd gallery from sea otter
https://www.vitalmtb.com/sea-otter-2025-day-2-part-1
Just the brakes? Any new derailleurs?
Gotta admit I'm pretty excited to see this upside down fork battle play out, I'm guessing more manufacturers will join the race. Both Fox/Cane Creek protos look dialed, the CC takes the cake with its machined looks but I'd happily ride either.
They dont hold asa back