Well here's about the best article I found on the many possibilities of why his chain flew off the big ring going over such a relatively small bump. The bottom line is that nobody knows. "Stuff happens". My best guess is a wonky chainline part, as his model of bike is not spec'd as being suitable for 1x. These bikes require one very specific "left side only" asymmetrical type of BB, and it's not spec'd for 1x use. Yes, high end bikes have gotten very very specific of what can and can't be used on them.
https://en.brujulabike.com/roglic-single-chainring-problem/ In the article SRAM "orbit" dampening system is mentioned. From SRAMs website it's not something the rider can turn off or have any say in it's function. *Orbit* *Reducing chain bounce is a crucial need for today’s riders that frequently venture off smoothly paved roads. SRAM’s Orbit™ technology, used in SRAM RED and Force eTap AXS rear derailleurs, limits chain bounce by controlling the chain’s downward movement when riding over bumps.* *Orbit is a new, patented design that consists of a silicone fluid damper with a one-way valve that controls the rear derailleur cage’s counter-clockwise rotation. This prevents the lower derailleur pulley from moving forward when bumps in the road cause g-force spikes that pull the chain downward. The damped cage rotation keeps the drivetrain quiet and helps prevent the chain from derailing off the chainring.* *The beauty of the lightweight Orbit fluid damper is that it is speed sensitive—meaning, the harsher the bump, the more resistance it applies to keep the chain under control. So, when the derailleur cage rotates counter-clockwise slowly—as it does during a downshift to an easier rear—the damper offers so little resistance, it’s as if the damper isn’t there. This allows you to get the benefits of a mechanical friction-style clutch when you need it, without the excessive chain tension these clutch types provide when you don’t. It’s the best of both worlds. And it’s a maintenance-free design so you spend less time wrenching and more time riding.* On Wednesday, May 31, 2023 at 6:48:23 PM UTC-4 Nick Payne wrote: > On Wednesday, 31 May 2023 at 11:23:36 am UTC+10 Garth wrote: > > I was watching the uphill penultimate TT road racing stage of the Giro D' > Italia this weekend where the eventual winner Primoz Roglic chose to run a > 1x for his TT bike. The announcers were "praising" him for the "innovative" > choice of using a mtb gearing setup for the TT. Well lo and behold, at a > low speed(which is fast for mere mortals, hah hah) he was about 2/3 up the > course and he ran over what appeared to be a small break in the road > crosswise and his chain derailed off the ring. He put it back on cool as a > cucumber and still trounced everyone, but so much for 1x's not failing like > any other system, because they do. > > > I'd say he was either not using a clutch derailleur, or had the clutch > disengaged to minimise drivetrain losses. My wife has been using 1x > drivetrains for years with clutch derailleurs, on all sorts of road > surfaces, and has never had the chain unship. She uses SRAM GX Eagle 1x12 > on one bike, and Eagle AXS on another. > > Nick Payne > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/f9e251ae-f15e-49ad-b1f3-b505dc87d12fn%40googlegroups.com.
