Hey. I bought a Yuni 26-inch Muni and I havent really ridden it that much. The problem is the the cranks keep getting loose after about 30 seconds of riding nomatter how hard I tighten them. The bolts don’t look stripped either. Could it be the cranks? Has this happened to anyone else or does anyone have any suggestions?
If you have not already used it, try placing several drops of thread locking cement on the crank landings and the threads of the bolts. Red Loctite from any auto parts store works well.
Also, I bought a socket for a 3/8" drive socket wrench at Sears that has a 8mm hex driver as the ‘socket’. Using this on a standard rachet driver allows getting the crank bolt good and tight without having to bear down heavily on a relatively small allen wrench.
Hope that helps,
When I first got my Yuni 29er, the cranks came loose the first couple of rides, but after tightening them a 2nd and 3rd time, they didnt get loose again.
Here is the basic procedure for installing square taper cranks on a unicycle: Square Taper Crank Installation and Maintenance
Grease, Loctite and a torque wrench. The important step is the torque wrench. Get the nut or bolt to 35-40 foot-pounds but no more than that. The torque wrench makes it easy to get it tight, but not too tight. Otherwise you’re just guessing.