Houston, we have a problem

The other day, when I was checking my rear brake, I noticed the bearings of the rear wheel rotating coarsely. In preparation for due maintenance I bought new bearings or rather bearing cages. The rear hub is a Shimano make and they use conical bearings, which have an adjustable play.

Bearings may not run smoothly anymore for a couple of reasons:

• There may be dirt in there (wouldn’t surprise me, given this year’s weather)
• one or more bearing ball may be damaged (easily rectified)
• one or both of the bearing races may be damaged (not easy and not cheap to fix)

Guess what, there was not dirt and 3 out of 4 races are in pristine condition, but one… not so much.

In the picture above you can see the non-drive side outer bearing race. Everything that’s shiny is in factory condition. The darker line, where the lower end flares out, is where the balls are touching the race. And then there is this rough bit (front and center), similar to the brake bumps leading up to a corner on the trail or a series of pot holes. Every time a ball passes over this bit, it drops a tiny bit and rattles against the edge of the little pit. This damages the area further and may also damage the bearing balls and then the whole thing is shot.

So I will need to have to replace this part. Fortunately it’s the race of the outer part. The inner race is part of the hub housing. Damage there would be the worst case. I hope I’ll receive the replacement by mid of next week. Until then my hardtail is grounded.

Bummer, but then again I neglected the Hightower far too long.

update

Today (Saturday – 4 days earlier than I hoped) I got the replacement outer bearing race.

Installing it was a cinch and done in 10 minutes. The majority of that time was taken up by realigning the disc brake caliper.

Bonus: The freehub is quieter now.