Ribble Ultra bar: Shimano doesn’t recommend use with its STI levers

IanMSpencer wrote:

I guess the question is what happens in a crash? I've never seen a Shimano lever detach in mangled bikes, though some SRAM ones do snap more readily under normal usage. . If the logic is that there is potential for a crash to create a pointy object that could impale the rider then there is at least a question to answer. Ribble may have done stress tests ensuring that it can maintain a suitable load from a straining rider, but have they done crash tests - might a rotating band absorb an impact in the way a different mounting system might not? Having been behind a rider hitting the deck a few times, their levers are always moved as the rider tends to ride into the ground as they fall.

Good point, the few times I've crashed the shifter normally rotates inwards (and needs a small amount of force to push it back). If it can't do this does the shifter/handlebar snap?

When I did the old 'drive into a multi-storey car park forgetting your bike is on the roof' thing my 105 shifters took the brunt of the collision.  They broke in the sense that they didn't work afterwards and needed replacing, but they stayed attached to the bike,

Of course, some journalist has asked these brands what they think of that. And of course, as stated in the above article, such brands, from a liability point of view, and out of fear for a bad rep if anything happens, respond as expected.

Next up: one of the brands will create a similar interface, (test it according to their standards,) try to patent it, and try to license it. Or make it proprietary so that only in-house bars can be used (which is a safer bet). Bingo!

Apart from that: a band may not be perfect given the shape of some handle bars, but it grips around a tube that distributes forces. A plate interface relies on the strenght of the material retaining the plate to handle all forces. That material better be very strong.

If I've understood the description correctly the plate sounds like a variation of the semi-circular wedges you get on seat posts.  Even having your hands pulling up and down on the hoods in a sprint or hill climb isnt going to compare to having your arse whacking up and down on a seat.   If you look at the bands they are pretty thin metal.

I dont think strength will be a problem.

It's the material that holds the plate that can be less strong. Currently there's an entire tube that needs to give before the clamp can entirely come detached.

I'm no engineer but as I understood it his point was a simple one: clamps traditionally (Shimano et al) have a square edge but attach to a round surface (the bar) and so have the potential to cause stress points and failure. He recommended a simple fix: make the clamp edges chamfered. Has any manufacturer done that?

It wasn't a shimano clamp though, it was a canyon clamp and, IIRC, PeakTorque suggested that it was because canyon had put the nut at the bar end allowing the bolt to pass through and touch the bar. Shimano (et al) put the bolt the bar end and the nut in the lever. You actually screw the nut onto the bolt and can't mark the bar no matter how far you screw it on.
As far as the lever is concerned i don't see a problem with the ribble attachment. It's a threaded stud the same as a standard clamp is.

Yeah the standard Shimano clamp is a thin steel band, which is both strong yet slightly 'flexible' in relative terms compared to the thicker rigid alloy one that Canyon designed. Add in the sharp edges on the alloy and the Canyon one was potentially creating a stress raiser at the bar/clamp interface which may lead to cracks in the carbon bar. The Shimano band shouldn't ever cause the same stress raiser, as the band will deform slightly to spread the load over a much bigger area.