Originally Posted by
mstateglfr
I am 235 and my 80s road bike frames with traditional tube diameters(which are exponentially more flexible than a modern Renegade's tubing diameter) hasn't ever made me think I am losing power due to frame flex. So my modern steel frames defintely havent made me think they are too flexible.
I do suggest you read up on power loss from frame flex. Measured results may surprise you.
Jan Heine wrote a nice article on that. I took exception to it because it doesn't always match my experience. Taking an extreme example with track racing - with my steel bike I can jump on a paceline or close a gap, but it took so much energy I couldn't hold on. With my stiff Aluminum bike I can jump on and hang with no problem.
Jan's reply was basically agreeing with me in that - if I'm putting down 1000+ watts in a competitive situation the frame flex is going to hold me back. But if I'm touring or doing a more typical ride at 150-200 watts, the frame flex will make little to no difference because the "loss" due to frame flex ends up springing back and propelling you forward with no net loss (Planing as he calls it). Like I reference below - I can do fine on a time trial or a 1 mile plus effort on a soft cush metal bike, but for a 10-20 second max effort soft metal doesn't do it.
So yeah, with most riding frame flex isn't an issue. For high intensity or competitive riding - it really does in my case.