Those bearings in the shock links are gonna yearn for better days...
It'd be interesting to measure the effective spring rate at the rear axle with a design like this. I wonder if it would be a noticeable difference due to added friction (high link forces, oblique angles, etc.). Sure, ball bearings have fairly low friction values, but a combination of high forces and high leverage ratios might make it noticeable.
it is my educated opinion, after looking at the photos, overlaying in linkage, assessing & comparing the kinematics with my extensive catalogue of images of Sam Hill, numerous CAD reverse engineering and plugging the outputs into my google supercomputer I have come to the conclusion that BIKE LOOKS FUCKIN SICK!
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the idler and the front chainring. is that common? i don't feel like i've noticed that before. it's such a short gap to see significant slack like that. i guess i shouldn't be surprised considering the abuse DH bikes get put through.
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the...
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the idler and the front chainring. is that common? i don't feel like i've noticed that before. it's such a short gap to see significant slack like that. i guess i shouldn't be surprised considering the abuse DH bikes get put through.
Most idler-equipped bikes have either negative or next to zero upper chain growth (it depends on the idler placement/configuration but most bikes on the market follow the same trend), so it isn't under tension in a compression absent other factors. We obviously know chain slap still happens on 'normal' bikes that do have upper chain growth, so I'd imagine that's amplified without any.
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the...
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the idler and the front chainring. is that common? i don't feel like i've noticed that before. it's such a short gap to see significant slack like that. i guess i shouldn't be surprised considering the abuse DH bikes get put through.
I think its pretty common, and why tooth profile and some kind of small guide is crucial for them. I'm not sure how many people are aware of it though, when you consider how many HP bikes come out without a good enough idler design and they have to modify it later.
The old Corsair bikes were shockers - they took several iterations to dial in their idlers, they even had a dual chainring set up which was a disaster - the chain would jump out of the sprocket and jam inside the tunnel which was terrifying if you went to pedal out of a corner and it had just locked up!
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the...
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the idler and the front chainring. is that common? i don't feel like i've noticed that before. it's such a short gap to see significant slack like that. i guess i shouldn't be surprised considering the abuse DH bikes get put through.
Chainring isn’t rotating, but the slack and whip in the chain between the cassette and idler would rotate the idler forward and create the slack between it and the chainring.
It has happened to me a couple of times on my Forbidden dreadnought, mostly on bike park days with bigger compressions or impact. The chain even got loose enough one time to almost derail from the top guide and made a sweet gouge on my swingarm. It is less bad now that I've switched to a new chain and the stainless idler (compared to the original narrow-wide idler). The chain seems to be really "active" on this part of the bike (in between idler and chainring)
It has happened to me a couple of times on my Forbidden dreadnought, mostly on bike park days with bigger compressions or impact. The chain even...
It has happened to me a couple of times on my Forbidden dreadnought, mostly on bike park days with bigger compressions or impact. The chain even got loose enough one time to almost derail from the top guide and made a sweet gouge on my swingarm. It is less bad now that I've switched to a new chain and the stainless idler (compared to the original narrow-wide idler). The chain seems to be really "active" on this part of the bike (in between idler and chainring)
Have never had a problem with it on my GT Force. Ran a mrp g5 SL as a lower for a season and now have the MXG (would highly recommend for any high pivot bike, almost no additional drag compared to not running one and haven’t dropped a chain once). Only time i dropped chains with it was before I had any kind of lower guide and it would pop off under high torque pedaling.
Sspomer - the chain goes slack on those bikes because the idler is not concentric to the main pivot, or the rear end uses a layout that is conducive to chain growth (FSR. etc)
Concentric to the pivot, single pivot design, no chain growth
Most of the idler bikes these days have moved the idler away (below) the main pivot modifying the antisquat to add pedal-ability, but have invited chain growth back to the party
They use different chainstays that allow to mount the idler in two different positions. The O-chain makes sense to reduce the feeling of the chain tugging on the pedals (the photos from the US champs clearly shows how much the chain bounces around between the idler and the chainring.
On Pirelli tires: the tires must not suck given riders had good results on them like Revelli's 6th place at MSA last year. However, I don't see how sponsoring a team like Trek can not backfire when their riders will use tires from different manufactures. Regular riders and fans won't even know they are sponsored by Pirelli, and those who actually "care" (like we vitards) will know they use different tires. It's great publicity for Maxxis and Bontrager (I think Bodi Kuhn uses Bontragers) but it's bad for Pirelli. Maybe there is indeed no such thing as bad publicity?
Pirelli doesn’t want to be Kenda with intense. They have plenty of experience developing tires in other sports and have seen plenty of tire brands spend lots of money just to be (often at least somewhat rightfully) blamed for bad results. Their product line might not be there for the very tip top of the sport. But it’s probably good enough for most riders and their splash into wcs is going to help them develop going forward and market their tires today.
That's not their hp6 dh bike. Something new? Second from lowest part looks like the uprights for a vpp rear triangle (or at least a solid rear triangle like vpp and dw use, a linkage driven single pivot can use one too, but vpp seems most probably). The part above it is part of the main frame (has a bb), but beyond that I can't figure out what's going on at all. I'm assuming the parts shown are all for the same prototype...?
From the other site: Interesting to see the modified idler position with an o-chain. Also nice “pirelli” rubber on there.
From the other site: Interesting to see the modified idler position with an o-chain. Also nice “pirelli” rubber on there.
So I had to re-mount Kailey's chain on her idler this weekend. She came through and it had popped off the side of the tiny little idler wheel and wouldn't go back on because it was essentially trapped in the little feeder hole inside the swingarm.
Finally got it back on the pulley wheel by using my finger as a "derailleur while her and another person held it up and I turned the cranks. I'm no rocket scientist but my immediate impression was that it was too damn tiny for that much force to go through a pulley wheel mounted so static.
This pic makes me think they're trying to move to something with more surface area capable of handling the heavy loads generated by the cranks.
NS's six-bar Fuzz prototype made another appearance at Hardline last week, this time without an idler: (see this article from a year ago for more details)
Another scary thing I noticed with this is the amount of bikes where the chain has basically lifted cleaned off the idler purely from the wheel travel. I'm shocked they stay on at all after a bottom out!
On sikmik83 's instagram you can see that Yeti already has addressed that chain slap between the little roller and the crank with a plastic cover over the chain.
It's called syn (syn.bike), made (presumably) by @synDev! Not sure what you mean about being unable to see the photo in Linkage, though:
Those bearings in the shock links are gonna yearn for better days...
It'd be interesting to measure the effective spring rate at the rear axle with a design like this. I wonder if it would be a noticeable difference due to added friction (high link forces, oblique angles, etc.). Sure, ball bearings have fairly low friction values, but a combination of high forces and high leverage ratios might make it noticeable.
Rock Shox new product launch Thursday, July 20th at 10am EST.
it is my educated opinion, after looking at the photos, overlaying in linkage, assessing & comparing the kinematics with my extensive catalogue of images of Sam Hill, numerous CAD reverse engineering and plugging the outputs into my google supercomputer I have come to the conclusion that BIKE LOOKS FUCKIN SICK!
Oops, guess I haven't found that feature yet. Syn is pretty cool though!
100%. Nothing will ever convince me to buy anything other than std linkage SP or DW variant etc
Hate?
working on a g-out project from national champs (full gallery up later), but these two photos caught my eye w/ the chain slacked out between the idler and the front chainring. is that common? i don't feel like i've noticed that before. it's such a short gap to see significant slack like that. i guess i shouldn't be surprised considering the abuse DH bikes get put through.
Most idler-equipped bikes have either negative or next to zero upper chain growth (it depends on the idler placement/configuration but most bikes on the market follow the same trend), so it isn't under tension in a compression absent other factors. We obviously know chain slap still happens on 'normal' bikes that do have upper chain growth, so I'd imagine that's amplified without any.
Those are very different suspension design philosophies,
why is that?
full g-out gallery is up
https://www.vitalmtb.com/g-out-project-u-s-mtb-national-championships-dh
I think its pretty common, and why tooth profile and some kind of small guide is crucial for them. I'm not sure how many people are aware of it though, when you consider how many HP bikes come out without a good enough idler design and they have to modify it later.
The old Corsair bikes were shockers - they took several iterations to dial in their idlers, they even had a dual chainring set up which was a disaster - the chain would jump out of the sprocket and jam inside the tunnel which was terrifying if you went to pedal out of a corner and it had just locked up!
Would have been great if there was a pic of the Vitus prototype smashed to its maximum in these photos… 😁
Chainring isn’t rotating, but the slack and whip in the chain between the cassette and idler would rotate the idler forward and create the slack between it and the chainring.
The Vitus prototype is currently on the other side of the Atlantic!
It has happened to me a couple of times on my Forbidden dreadnought, mostly on bike park days with bigger compressions or impact. The chain even got loose enough one time to almost derail from the top guide and made a sweet gouge on my swingarm. It is less bad now that I've switched to a new chain and the stainless idler (compared to the original narrow-wide idler). The chain seems to be really "active" on this part of the bike (in between idler and chainring)
Have never had a problem with it on my GT Force. Ran a mrp g5 SL as a lower for a season and now have the MXG (would highly recommend for any high pivot bike, almost no additional drag compared to not running one and haven’t dropped a chain once). Only time i dropped chains with it was before I had any kind of lower guide and it would pop off under high torque pedaling.
Sspomer - the chain goes slack on those bikes because the idler is not concentric to the main pivot, or the rear end uses a layout that is conducive to chain growth (FSR. etc)
Concentric to the pivot, single pivot design, no chain growth
Most of the idler bikes these days have moved the idler away (below) the main pivot modifying the antisquat to add pedal-ability, but have invited chain growth back to the party
From the other site: Interesting to see the modified idler position with an o-chain. Also nice “pirelli” rubber on there.
They use different chainstays that allow to mount the idler in two different positions. The O-chain makes sense to reduce the feeling of the chain tugging on the pedals (the photos from the US champs clearly shows how much the chain bounces around between the idler and the chainring.
On Pirelli tires: the tires must not suck given riders had good results on them like Revelli's 6th place at MSA last year. However, I don't see how sponsoring a team like Trek can not backfire when their riders will use tires from different manufactures. Regular riders and fans won't even know they are sponsored by Pirelli, and those who actually "care" (like we vitards) will know they use different tires. It's great publicity for Maxxis and Bontrager (I think Bodi Kuhn uses Bontragers) but it's bad for Pirelli. Maybe there is indeed no such thing as bad publicity?
Pirelli doesn’t want to be Kenda with intense. They have plenty of experience developing tires in other sports and have seen plenty of tire brands spend lots of money just to be (often at least somewhat rightfully) blamed for bad results. Their product line might not be there for the very tip top of the sport. But it’s probably good enough for most riders and their splash into wcs is going to help them develop going forward and market their tires today.
That's not their hp6 dh bike. Something new? Second from lowest part looks like the uprights for a vpp rear triangle (or at least a solid rear triangle like vpp and dw use, a linkage driven single pivot can use one too, but vpp seems most probably). The part above it is part of the main frame (has a bb), but beyond that I can't figure out what's going on at all. I'm assuming the parts shown are all for the same prototype...?
So I had to re-mount Kailey's chain on her idler this weekend. She came through and it had popped off the side of the tiny little idler wheel and wouldn't go back on because it was essentially trapped in the little feeder hole inside the swingarm.
Finally got it back on the pulley wheel by using my finger as a "derailleur while her and another person held it up and I turned the cranks. I'm no rocket scientist but my immediate impression was that it was too damn tiny for that much force to go through a pulley wheel mounted so static.
This pic makes me think they're trying to move to something with more surface area capable of handling the heavy loads generated by the cranks.
NS's six-bar Fuzz prototype made another appearance at Hardline last week, this time without an idler: (see this article from a year ago for more details)
Another scary thing I noticed with this is the amount of bikes where the chain has basically lifted cleaned off the idler purely from the wheel travel. I'm shocked they stay on at all after a bottom out!
On sikmik83 's instagram you can see that Yeti already has addressed that chain slap between the little roller and the crank with a plastic cover over the chain.
Mic Williams from WRP / Trinity sat down with Jace on Gypsy tales podcast. Talk a bit about the old Hondas, gear boxes, and current projects.
Frameworks enduro in-depth
Saw a promo for the new 13s XTR today. Must be around the corner…
New boxxer soon.
Post a reply to: MTB Tech Rumors and Innovation