Changed crankset, now experiencing knee pain

roubaixtom

Hi,

I have recently replaced my Shimano 105 5800 chainset with an Ultegra 6800, both 170mm crank length.

Since I have been experiencing knee pain (both knees). Not ride stopping but defiantly there.

Im struggling to find a reason why the new cranks are causing an issue, both 170mm and Q factor only 0.6mm difference.

Any help would be much appreciated, thank you

BrandonA

Do you still own the original one and are you able to install it yourself? I ask as I wonder whether it might be worth putting the old one back on and seeing if the pain goes away.

fenix

Probably nothing to do with the chainset ? Same gear ratios ?

fat daddy

did you do the work to fit it all or was it done in an LBS ??? ....... I would recheck your cockpit geometry if someone has re-positioned the saddle, bars, shifters it could change the angles your legs are working through ...... yes even shifters, if the bar has been rotated and you are stretching further forward you might now be sitting further forward on the saddle to compensate without realising it

roubaixtom

Hi, I sold the previous chainset.

The groupset was installed by me, have built many bikes before and marked exactly where shifters where to be placed on bars. Saddle height, fore/aft, tilt is the same. Haven't changed bar position. Same gear ratios also

fenix

Coincidence then ?

fat daddy

perhaps is the effect of having a lighter more impressive looking chainset that's making you pedal harder and faster that's screwing up your knees ..... have you also seen a rise in Stava Kudos's or dead bugs on your helmet (on your head !)