Why am I faster on my tri bike? (Page 2)

Originally posted by fisherman76 not to nit pick, but I'll nit pick - stiffness can affect the amount of power transferred to the pedal from the body, and it can be measured in power output...but you're right if the OP is describing stiffness as 'teeth jarring', that's not so much referring to frame and bottom bracket stiffness as it is the combination of wheel and fork stiffness, which don't directly affect power output (other than the fact that he's uncomfortable with the teeth jarring, which indirectly affects power!). So, yes, let the air out a bit. Make sure you're not using studded tires, stop riding on gravel (just kidding on both), and if you have the means, switch to a carbon wheelset. Wheel stiffness is a totally separate discussion, which fortunately for us was nicely examined on ST, and deserves a read: http://www.slowtwitch.com/Tech/Debunking_Wheel_Stiffness_3449.htmledited - the author of that article was not Dan Empfield, it was Greg Kopecky.