Originally Posted by DangerousDanR

I have a Lynskey R350 rim brake frame. I have a Bontrager carbon fork and Rolf Echelon wheels on the bike. Mine is a size XL, so that may make a difference.

I have never felt anything that I associated with frame flex, like shifting when pedaling hard or brake rub. It does not bob or weave when cornering hard. I have probably about 4K miles on it, and not any issues. The roads here are primarily flat, but I do make a habit of riding a multi story parking ramp which is about half a kilometre in length

I am about 105 Kilograms, so well into the Clydesdale range. The last time I was in a gym was about 5 years ago, and I could limit out the leg press machines at around 350 kilograms force, so I think I can still put quite a bit of force into the cranks.