15 Jan 2014

Adjusting for tolerances


A wheelbuilder can’t help but scrutinize hubs, rims and spokes that cross his/her bench. One thing we look at is tolerances. A cartridge bearing, for example, should have an interference fit with bearing bores on compatible hubs. Some hubs hold their bearings firmly and others are too loose. At first glance a slip fit seems simpler for the DIY mechanic but a slip fit can allow slight play in the wheel. Play is no good because it’s your cue adjustment is lost or bearings are worn.

These hubs are a good example — out of the box I found the bearings slightly loose. In cases like this I re-install bearings with a thin layer of Loctite 641 applied to the outer races. Loctite makes a variety of industrial bearing retainer compounds. I use 641 because it’s a low viscosity formula that makes it easy to apply thinly and because it’s the lowest strength sold. Bearings can be pulled easily, which is super important. No charge for this attention from your friendly nationwide wheelbuilder.