Going from my previous post, My Q factor is too narrow for my frame, so I need 1 too many spacers, I can put that crank set on my gravel bike, So I'm looking at ordering a new crank set for my MTB, According to the diagram its a 131.6mm between the two chain stays.
The current one I have installed is listed as 135mm, hence its a little close to the frame and might rub if I remove a spacer off each side of the BB.
Would a Q factor of 153mm be enough or would I need to get more of a larger in size like 181.5mm?
by Masteruserfuser
3 Comments
Depends on the crank length and thickness cranks Arent 195mm long normally (wallthicknes of the threaded part for the axle is less than 20mm normally) so its narrower than the listed 131.6mm however the thickness of your cranks is also relevant. Q-factor is measured on the outside of the crank where for you the inside is relevant, some cranks get that specified in the technical drawings.
So look up the width of the crank arms themselves and reduce that form the Q-factor/look up inner width itself. Then measure the frame at crankarm length plus 15mm.
Are they 195mm cranks though? I’m not very familiar with the MTB world but 195mm seems crazy long to me. The longest I’ve ever seen for the road is like 177,5mm which is only available to pros, most people run either a 170, 172,5 or a 175mm. That would give you a few more mms of clearance I guess.
Q factor is measure of ouside of cranks width. ~180mm Q-factor cranks have around 150mm inside.
So you propably clear it with 170 q-factor cranks, 180mm are safest bet.