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Do you guys measure flex in a lab setting when designing bikes? Or perhaps more interestingly do batch testing for flexiness during production. I know from first hand experience due to frame alignment and normal manufacturing variations some bikes wobble (not flexing I know) quite a bit when shaken from the BB or read wheel due to how the pivots and bearings all seat together and some are absolutely rock solid. I know manufacturing tolerances is a different question but as designers do you consider this when designing compliance into a frame?

Flex is great... until it isn't. It seems to be this subtle thing that is largely ignored or not reacted to, until a big flex happens where the bike seems to "disappear" for moment, providing that "vague" feeling and possibly shaking confidence. Flex also seems to be something that is both structurally and input driven. So a minor flex on a mellow event can turn into a larger flex in a high load event. A couple of questions: - when talking roll and wag flex, how many millimeters: is a little, is a lot - For a consumer's bike, how...

I have a question about the stiffness and compliance on the bike as a whole system and is there anyone looking at this? For example: you talk about the tradeoffs in the RT but if paired with a rear certain wheel does that is overly stiff or compliant are you negating the effects in some regard. Or on the other end, an overly stiff front paired with a inverted fork might be better than a traditional fork. I guess to simplify it, if you were to design a bike just for your preferences would the stiffness of your preferred components...

Is there a benchmark frame that you have found to be the ideal mix of compliance and ride feel?

Been experimenting with larger grips as opposed to smaller ones and notice they’re easier to grip as OD increases. I have smaller than average hands so I have doubts we’re really addressing this problem correctly.

Hi Ryan! Awesome post, thank you very much! What are your thougths about different frame materials in regards of stiffnes and compliance? Makes sense to you that carbon and alloy versions of a frame share the same design/layout? What do you think about steel full suspension bikes?

Yeah definitely I run a more comfort setting than performance. I guess part of our compliance comes from frame material as well. I personally I have never rode a carbon front end that had the same comfort and vibration damping of a steel, aluminum or print/bonded frame. Everyone is different, so I understand it’s tough to just make one frame that racers and consumers are all going to thrive on. Have you seen the fore/aft compliance on this bike Sam P was riding? lol

For sure, I agree with you. I love this type of content. I am running OneUp Aluminum bar, Ochain. I have mass dampers on my current frame, but I didn't run them on Fury. To onto PacoJo question, I have been using SynBike data acquisition to measure frame movements with the 6axis IMU's. I've only had it on 2 frames now, but would interesting to hear how the baseline of compliance is chosen, FEA or ride tested on dirt?

Photos here of Danny's modified rear end from PB for people who haven't seen it.

to expand on rhodefab's original question a bit, I'm curious how stiffness is analyzed for geometrically complex systems like full suspension bikes. how do you find yourself estimating total stiffness in a given direction (like roll or wag) most often? I can see a springs-in-series approach being useful for quick iterations, but I'd assume that FEA tools are necessary at some point to get more accurate values, assuming that you aren't yet ready to test it on a load rig. also, awesome writeup in your initial post. it really helped piece together some of the intuitions I had about what...