My guess is flattening a chainstay to increase or concentrate flex is pretty theoretical and can’t really be felt on the bike (without a healthy dose of confirmation bias) but, can engineering folks confirm or deny this in the context of a steel frame with real data/analysis?
To riff on a quote from @Luniz82 the FEA pictures I have seen of bikes shows ‘chainstays are blue’.
- Do chainstays flex in the vertical plane and what does that mean for seatstays? Do they need to be thin enough to allow compression/bowing?
- Wouldn’t the stress be in tension? If so, how does squishing the tube change this?
- Has anyone measured the vertical flex (as a rear HT assembly) and is it enough that anyone would be able to feel it?
- Finally, assuming quishing does increase or control flex in some material way, doesn’t concentrating flex to a smaller area increase the stress on that area and create the potential failure point?