CyclingTips podcast: Does frame stiffness matter?

[fiamme red]

https://cyclingtips.com/2017/06/cycl...ffness-matter/

[Gummee]

Historically, I think a little flex is what made Ducatis faster than they should have been.

All the big Japanese makers had to engineer a little flex into their chassis to help em turn.

Least that's what I rermember reading

M

[paredown]

Good conversation...worth a listen. Thanks!

[Clean39T]

http://forums.thepaceline.net/showth...ht=cyclingtips

Merge?

[jmoore]

Only if they are laterally compliant

Sent from my SAMSUNG-SM-G890A using Tapatalk

[ultraman6970]

Remember the 1st gen look carbon frames, like the one that is/was for sale a few days ago, those were built with some flex to help you pedal... I wouldnt call it flex but may be harmonics because the frame suppouse to adjust to the way you pedal and help you to over come the death spot easily (or something like that was claimed) a friend tested one back in the day and he said that the bike once over the pedals was super nice, so I assume what looks claimed was real?

[Ken Robb]

Motorcycle suspension works best when the bike is vertical so the wheels can move up/down. The farther away from vertical the bike leans the less the wheels can move up and down. At extreme lean angles the suspension can move very little as the impact forces are mostly sideways to the axis of the shocks and fork. Up to a point stiffening the chassis eliminated some frame flexing and the wobbling it induced.

But eventually frames got too stiff and handling got worse. It seems that SOME flex was needed for optimum handling. I guess the little bit of "give" in the frame acted to replace some of the suspension compliance lost due to extreme lean angles.

[false_Aest]

It's a good podcast!

Ever since I read one of Dave Kirk's posts on his Terraplane design I've been keenly aware of how people were chasing stiffness w/out really knowing why.

My current whip doesn't lunge forward the way other bikes I've owned have (CAADs, CF wonders, etc) but I swear to you it's one of the faster bikes I've ridden. I think part of it has to do with how I can apply a bit of "english" through a tight turn in a way I can't with a stiff-stiff bike.

I think the whole "planing" thing is ridiculous but I do believe that there is optimal stiffness for a rider's power output and weight and I think that was explained rather well.

[8aaron8]

I will be listening to this later, thanks for sharing.

In my own experience I can say that I much prefer a bike that has some flex, I'm sure my low weight means the amount of flex I tolerate in a frame would be another persons wet noodle. However, having built myself a number of frames over the years, mixing tubes trying to fine tune the frame I have come to find that good old standard dimension 1" tubing personally gives me the characteristics I desire in a frame. I believe a little bit of spring is a good thing, in my riding it prevents those dead spots, which I did experience with OS tubing, specifically in a down tube. Too much flex however can be a nightmare so learning about your own riding style can be helpful in finding the right frame.