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
My understanding is that manufacturers mostly build carbon frames from the ground up (as opposed to being assembled from pre-manufactured tubes, a la Atherton Bikes), and that layup patterns don't vary much or at all between sizes (with a few notable exceptions). But that might be old wisdom on my part, and perhaps the industry is more sophisticated in the way it designs layup patternds now. Maybe everyone is tuning thickness and layup pattern between sizes, but only a few brands are explicitly advertising it.
Here's an example of Unno's layup for the Dash 130:
Awesome! So it’s something any reasonable fox serving company could do.
Here’s a Hail Mary, do you have any dyno charts/actual data showing the improvements over the previous gripx2? I think it would be really appreciated to see some numbers behind the claims.
Compared the S1 to the S4 at the same center of gravity (650mm above BB ) and at adjusted CoG for the shortest and tallest riders on Forbidden's chart (160cm and 198cm).
Turns out that Forbidden knows how to design bikes and that moving the BB on the front triangle is the way to do it. A change in CoG has a much bigger impact on kinematics than the rear center length.
With that being said, there's probably a (marginal) benefit to slightly changing the main pivot height on the smaller frames to reduce the anti-squat and compensate for the lower CoG. But again, splitting hairs.
Yeah by tube thickness I meant layup for carbon bikes.
We know the smaller frames are lighter, so they aren't just using the same layup and having increased overlap etc. But is it intentionally designed with more flex giving it's a smaller triangle, and most likely will be ridden by lighter riders.
Listen I know it’s pedantic but there is a big difference between moving the BB forward vs moving the pivots backward. When you look at the overlay it’s clear to me that they are adding material behind the seat tube to get the pivots further back.
I suppose you could say they are moving the BB and seat tube forward but that doesn’t make much sense as th front center is also growing. Better to use the BB as a reference point and say that the front and rear centers grow out from there.
Nah. Top tube straight continuous to seat stays is very 2020. Now it’s all about the grasshopper. Steep down tube to low flat chainstay. And I’m all for it.
Maybe your right, straight line is industrial design where grasshopper, is sex.
as long as no one does steeper chainstays than top tube. 🤮
Yeah with shifting the BB relative to front triangle pivot points (assuming no concentric BB pivot) there’s no impact on leverage curve, which is kind of nice. The change in anti-squat would be pretty hard to notice. Anti-rise I do think would be noticeably different, but there’s a pretty wide range that people are fine riding so that’s not the biggest deal.
Going the route of changing the chainstays and/or seatstays, it is possible to decrease the impact on the kinematics by moving the pivot points on the front triangle.
I can’t think of a brand off the top of my head that changes linkages with frame size as well. Not including bikes that only come with a 27.5 rear wheel on smaller sizes since that’s an option on larger sizes as well. Specialized likes to do different chainstays and seatstays, but link remains the same across sizes. I think generally their chainstays and seatstays cover two sizes per version so S1-S6 is three different versions.
Pivot says they change kinematics on each size, but I don't think they manufacture a different set of links to do it, I think they just shift mounting points on the front triangle: https://www.pivotcycles.com/en-us/technology/size-specific-design-and-ride-tuning
Pivot says: "For bikes where chainstay length varies with size, suspension kinematics naturally change. However, we modify pivot points to ensure optimal curves for each size. We optimize the kinematics for each frame size based on a rider’s center of gravity and average saddle height per size to ensure consistent suspension kinematics for every size rider."
Other than that, the only other company I can think of is RAAW, who offer two different "rider-weight-specific rocker links" so heavier riders can have more damping and lighter riders can have less:
And Nicolai/Geometron.
The leverage do not change at all if the "chainstay" growth is from pivot point offset. The same seatstay and chainstay members are used. Leverage is entirely independent of BB position.
As someone pointed out technically the antisquat changes a tiny bit but the effect is basically negligible (like 1% per 5mm of rear center change in the pedaling region).
You can see this in the graphs below which show the same bike with a 430/435/440 rear center. The first show leverage differences if you just make longer chainstay/seatstays. The second shows the same effect with BB offset (you can't even tell the curves apart). The third shows antisquat differences for the BB offset configuration. The antisquat differences might look significant but that is just because the A/S curve is pretty flat. 1-2% is not something you would feel and is vastly overshadowed by impacts like chainring size, gear selection, and body center of gravity. Pedal kickback is similar. <1deg difference at full bottom out between a 430 and a 440 mm chainstay.
Kavenz also has standard and leverage+ rockers, though I think there will just be one rocker for the V8 and different lower shock mount points to change leverage.
That’s an old photo of Conners Bronson 4.1.
I should have said “adds meaningful weight”. Maybe I’m just a nerd but every ride no matter how short I take a pump, multi tool, tube, water so that extra weight is there no matter what. A small weight penalty is worth getting that extra weight off my body and on lowest point of the bike… literally where WC racers are strapping weights to make the bike handle better.
My Stumpy Evo alloy frame is lighter than an alloy Sentinel with no frame storage.
Doesn’t weight distribution matter much more than total weight?
Two different bikes isn't a far comparison. The question the designer asks is "how much material do I need to add, and where do I need to add it, to compensate for the loss of strength from cutting a giant hole in the downtube?" It can't not add weight because a U section is weaker than a closed hollow section of the same external dimensions and mass.
Fuck me this thread is interesting
I think so, I was able to get the new Scott Gambler in the 10 level build, so carbon front triangle and aluminum rear, in an XL. It weighs the same as my size L aluminum Norco Sight, 39ish lbs, and even though the Scott has a 20+mm longer rear end and reach, because the front triangle is lighter I can get it up just as easily, the weights concentrated more around the bb and rear end than it is on the Norco. It's a little thing that I noticed, that is going to make a pretty big difference in how the bike will feel while riding it.
Yessir they rock
I'm wondering that nobody posted this here yet. German youtuber found something on Cyclingworld in Düsseldorf.
Propain Ekano AL prototype with heavily masked mystery motor...(Avinox)
avinox m2 motor
New Devinci Wilson/dh bike? It's not a Chainsaw. (Doesn’t have the same top/seat tube junction, has a 2chainz thing going on, etc)
https://www.instagram.com/p/DWNFD9Xjz9d/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==
lol it's a pivot
Lol. I guess all the Devinci jerseys (and rumours of an upcoming new Wilson) had my hopes up and I jumped the gun. Ha ha
I’ve wondered for the past 2-3 years why Devinci didn’t put that proto-HP Wilson in production, the gravity-est bike they have is the Chainsaw which, although pretty versatile and with 180mm at the bike, still ain’t a dh-bike…
Prototypes are for testing. Sometimes the conclusion of a test is that it's not a better bike, or not commercially viable. So you don't put it into production.
If memory serves right, the testers were impressed by the proto. Like, really impressed! Now what “not commercially viable” means is beyond my understanding.
When that prototype was built enduro was still all the rage in Canada and sales of downhill bikes were down
"Commercially Viable" means you can bring an item to market expecting to profit.
DH bikes are an incredibly small share of the bike market which can make it tough to be commercially viable. So much so that many bike companies see DH racing primarily as a marketing activity. For instance I don't think there were ever production versions of the Yeti rail bike, Hyper's freeride bike, the Honda bike, or Herbold's suspension Miyata.
I meant my comment to relate to prototypes generally, not specifically to the Devinci you mentioned.
You could definitely buy a Yeti 303.
I did a race on a mates and definitely didn't OTB and fling it into a rock garden and dent it...
Honda was only ever a proto, I think 6 total were made from memory?
notice in the race replay from TN national that dylan maples' pivot dropouts look custom/different (sorry, wish i had a better angle).
edit - found this
Dealer just sent this out
Post a reply to: 2026 MTB Tech Rumors and Innovation - Longer and Slacker