I got those too but haven't used them yet.
As far as i know, if the threaded area (crank) is deeper than 1.5x the diameter of the bolt itself, you're good (learnt this in some material strength calculation class in college). So say the bolt is a 12mm, if it's threaded at least 18mm in, in general this would give u sufficient clamping force. I believe it also depends on the strength of the material itself and what it's threaded into, but in steel in general 1.5x OD is good. Threading into aluminum? Go in 3x OD.
So measure the bolt length, extract the flywheel thickness. What u have left is what's threaded inside the crank.
Last edited by Speedingmofa
on 2016-11-17
at 08-30-09.