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If we’re now moving the discussion on to braking then that’s a completely separate thing and just as we can’t lump all four bars, faux bars, flex stays, etc together; nor can we brake designs. I don’t feel attacked, that’s okay. Trolled maybe. And it’s not a funny way to say anything, it’s first hand experience. I get many queries from riders about the flex stay arrangement of my frames. Folks are rightly or wrongly concerned about flexing elements of their frame. I’m always pleased to explain that the degree of flex is so small that it’s insignificant to the...

FWIW carbon fibre damps a lot more than metals. And a handlebar can also be somewhat damped 😉 Aaaand I'm out. I think we ran the course of the debate and are spinning in circles.

No need to do that.

Stable Ad? Stab Lead? how are we supposed to read that?

Using weed based composites in vehicle production is nothing new, they were doing it years ago. 🤣

I was working in the engineering department at Specialized during the whole "zertz" thing. They did absolutely nothing. We tested frames with them and without them on an MTS test bed as well as having strain gauges/etc and DAQ systems on for riding. They did not damp or mute anything, zero difference. The shape of the carbon stay itself did change how the rear end behaved when compared to a "normal" seat stay, but the zertz did nothing. It even got to the point where Specialized was ordering field test frames without them as the cost was a bit lower...

The strange behavior at the shock you can see there is due to the tire. In my opinion most, if not all, the suspension performance gripes that people have with flex stay bikes is mostly due to the fact that they are typically less gravity oriented so suspension performance for descending is not prioritized. The Stumpjumper 15 and the Stumpjumper 15 Evo are the same bike. In the previous Stumpjumper generation, the flex stay Stumpjumper was very different from the rest of the Stumpjumper models.

That's great and now I get it; thank you! I brought it up and your description of how I was thinking about it is correct; really appreciate all the thoughtful responses and discussion here.

Carbon can some impressive stuff, not too worried about a few mm of flex

Thanks for all the input, fascinating (to me at least) subject and let's move the discussion here: https://www.vitalmtb.com/forums/hub/flex-stay-discussion-thread

When we agree, we agree pretty damn well.

Any extra pressure in brakes will go somewhere. Either inflate the bladder (and could cause problems once water is ingested and the volume increases, see option two) or the caliper pistons will push out and advance towards the rotor to take up the slack. The timing of the port will stay the same and the brakes will grab at the same time. Maybe the bite point will be quicker because the pads are advanced more, but you don't need to overfill the system to achieve that, just advance the pistons. Or get contact point adjust brakes...

Haven't seen any media on this but found it interesting that Shimano also released a battery-less self shifting electronic derailleur for commuting under the cues umbrella. https://bike.shimano.com/en-AU/technologies/details/qauto.html

I had this exact case on a GX Eagle chain in 2019. The only chain I broke in the last 20 years except for the one I used for 6 seasons on my primary bike when I was a broke student. Broke that one twice in two weeks, it was just gone.

and a bottle of the new brake fluid