Hitchcocks Forum

Think I may have found out why my Himalayan has destroyed its front wheel bearings so quickly.

The spacer between the bearings was 0.5mm shorter than the distance between the bearings when fitted in the hub, so I have made up a new spacer that is the same length as the distance between the fitted bearings.

My thinking is that when you tighten the axle nut up the bearings are subjected to an axial load if the spacer is too short - happy to be told I am wrong but I would have thought that this is the cause of the premature failure of the bearings which were both well lubricated.

Lets see how things are in another 6000 miles...

You may well be right Andy

Yup. Bound to fail. The fork legs, spacers and inner races should form a single constant tube when the spindle is fully tightened. Any side load will be on an angle from cornering forces (one side at the top, other side at the bottom), they'll be relatively low (most of the cornering force is still radial load because the bike is angled over) and only when cornering.

While grooved balls are designed to cope with some lateral load, with short spacers, it'll have been seeing a very high and constant lateral load from the same direction. The balls will have constantly been forced against one side of the groove.

Andy, your assumption makes complete sense to me

I'm sure that you've found the cause of the bearing failure.

Chalk-up another discovery of lousy quality control at the factory!