Clutch equipped? SRAM hasn't let any information slip at this point, but taking a closer look at the prototype unit reveals that it seems to use a standard parallelogram, the very same as SRAM employs on their XO level unit. What is clearly different, though, is the derailleur's larger than usual knuckle. What does it do? Why is it so big? There is only one reason in our minds: the prototype is an answer to Shimano's friction clutch equipped XTR Plus derailleur that uses a roller clutch to keep its cage from swinging wildly back and forth over rough terrain, helping to greatly limit chain slap. Less noise is only part of the story; there also being an actual performance gain to be had thanks to the cage's greater tension helping to keep the chain from bouncing off of the ring over rough terrain. The system has received positive reviews, and it looks as if SRAM is also ready to debut a design of their own, although we're willing to bet that the drivetrain engineers at SRAM have been tinkering with the idea for quite awhile. Roller clutches are far from new technology, after all.
What we don't know at this point is how the system functions. We're willing to bet that the internal design differs from Shimano's enough to avoid any sort of patent issues, but can only speculate as to its makeup. From the angles shown above there doesn't seem to be any sort of on/off switch, as found on the Shimano unit in the form of a gold anodized lever, that would allow the clutch to be engaged and disengaged. If this is the case the SRAM prototype surely uses a different layout, likely simpler than found in the XTR Plus derailleur. Then again, it remains to be seen what is hidden underneath what looks to be the large torx head cap on the knuckle's outer face. SRAM has kept quiet on when we can expect to see a production unit, but the prototype shown above does look close to being finished.
Stay tuned to PB for more information as it becomes available!www.sram.com
1) people are still weight weenies (even though the modern day world cup DH bike is 30ish lbs, look back 5-10 years and it was 40, thats a 25% reduction but we're still chasing those 10ths of a gram)
2) Gearboxs require the frames to be designed around them and Shimano and SRAM are about putting out a universal product for the industry standard
that simple, too heavy and not universalizable, bummer
2) That's the main problem I see. The innovation will have to come from the frame makers. I don't really see it coming from sram/shimano as they'd basically have to tell the bike makers how to build their bike if the drivetrain has to be an integral part of the frame. I'm not sure shimano wants to get into that and I'm not sure bike makers would welcome that either.
If we can shift gears here (pun intended) this is one of the cooler innovations in the bicycle gear box world. Way far from production viability but still, CVT on a bike, blows my mind
ls1.pinkbike.org/185/sprt/i/kvid/kvid-rms1.10.swf?ad=0&a=0&l=0&w=640&h=480&dur=372.00&u=videosift.com/video/Infinitely-Variable-Gearbox-For-Bikes&uid=1811&id=758&title=Derek%20Lahr&un=spoiledgoods&i=lv1.pinkbike.org/vt/1/vt-758.jpg&t=1328906863
In my personal experience SRAM stuff falls apart very quickly, but Shimano just keeps on trucking. SRAM does come in pretty colours though!
Agreed, this is a slightly pointless debate - although strangely enough I'd rather have a SRAM chain than a Shimano?!
Shake hands and agree to disagree ;+)
Basically you want high speed compression damping on the cage, seems to me like one of those "why didnt anyone make this before" things.
Just a thought!
All you need is 2 grands now.
www.vitalmtb.com/product/feature/SRAMs-New-Four-Piston-Brakes,105?utm_source=facebook.com&utm_medium=referral&utm_campaign=spotlight
Just a bigger spring underneath the torx cap? Either way not really that interesting...