Kurbeln mit Splintbefestigung: Unterschied zwischen den Versionen

Viele ältere Fahrräder hatten keilförmige Splinte, mit denen die [[Kurbel]]n gegen die [[Innenlager]]achse befestigt wurden. Diese Splinte haben ein Gewinde, auf das man eine Mutter schrauben kann, die den Splint befestigt. Diese Art Kurbeln sind schwierig zu demontieren. Insbesondere, wenn die Kurbeln lange nicht demontiert wurden, erhöht sich diese Schwierigkeut erheblich.

It is commonly necessary to file the flats to fit. To file a cotter, put it in a vise at an angle so that the flat is parallel to the vise jaws. When filing, apply a slight twisting force to the file handle to apply more pressure to the wide side of the flat, to help maintain the correct angle of the flat.

You cannot get a cotter tight enough by tightening the nut: you must use a press or a hammer. Cotters are made of fairly soft steel, so that they won't damage the axle. If you try to tighten them just by turning the nut, either you won't get them tight enough, or you will strip the threads.

 

After a cottered crank has been re-assembled, the bicycle should be ridden for a few dozen miles, then the cotter re-tightened with a press or hammer. If this is not done, the cotter will probably loosen up. If the bicycle is ridden with loose cotters, the motion of the crank will cause the axle to cut notches into the cotters, and it will become impossible to tighten them.