henrybsick

Giant needs to stop fiddling about and start posting the weights of their builds. I respect the hell out of the leverage they bring to the market and strategy they can implement... but ffs let me get a ballpark for the heft.

@bikeracer28: for each link, it rotates twice for every pulley it travels through. It bends as it enters, and then again as it exits the pulley teeth. Through the rotational travel of the pulley, a fully engaged link does not rotate with respect to its adjacent links. So, the wrap angle of the pulley ends up affecting only the time between link motions (on & off) and not affect a total amount of link motion.

@cedric-eveleigh: OK, went back and did some quick maths. You are absolutely correct and I am a bit humbled. I think my intuition steered my to assume that this was similar to the case of additional inflection point (which would be a more significant driver) however Supre does not add an inflection point in the chain path. (The high pivot is another story but not relevant to apples-apples comparison). Did not wake up this morning expecting to brain fart on a system that I have analysed, designed, and implemented many times... however here we are. Thanks for your comments!

@cedric-eveleigh: You are correct in pointing out the angle per link difference, however total chain path wrap angle is an indicator of how many times the links will need to bend to achieve the path. Point being, the huge difference in total wrap angle is more significant than small angle per link differences when only considering diameters of pulleys. In general the straighter the chain path the more efficient the system. Larger pulleys nudge a fixed system towards more efficiency vs smaller pulleys, but bigger levers are at play when the chain is simply require to bend more (again, hundreds vs tens of degrees).

@hamncheez: The addition of a high pivot idler does not change the total wrap angle of a traditional derailleur system, for what it's worth.

**typo in first response outlining wrap angle diff. ~230° more in little cog and 100° more in big cog (not 300°)

Innovation for sure. Definitely something for a DH / Enduro bike to consider, even with how low profile derailleurs in the modern era have become. That said, the talk of big Idler pulleys for better efficiency is a misleading claim. I don't want to detract from the ingenuity of this approach, however I do have a problem with stretched marketing... Larger idler pulleys reduce wasted energy by decreasing overall chain wrap angle. A design like Supre inherently has much more total wrap than a traditional derailleur system. I certainly may be missing something here, but it looks like Supre will induce ~230° more wrap while in little cog and ~300° more total chain wrap in big cog. These are an order of magnitude greater than the wrap reduction achieved moving a normal derail to larger idlers (tens vs hundreds of degrees. This is why it could be cool for DH / Enduro bikes - where efficiency matters less. (Gearbox is ideal for DH tbh... un-sprung mass on rear wheel minimized & shift capable while not pedaling to name some big points) All in all really cool to see the passion of folks in the community and the results that come from some interesting ideas and a lot of hard work.

I'm all for owning up on a product issue/defect and coming clean.. however I'm very dubious about the claim that this issue with adhesive was not foreseeable...

Until now, Pedro's are the ONLY levers I trust because their glass-filled-nylon composition. These carbon tire levers are probably the only other option I would try. Not sure why the assertion is that these would break (laminated 3k weave) when GFN does not break.

Atherton Bikes would like a word