In this article I’m going to explain how to easily repair damaged and pitted hub cones.
Hub cones are extremely prone to damage. As the hubs are exposed to the elements, and especially in wet conditions, corrosion starts eating away at the bearings and the bearing race (the place where the bearings make contact with the hub). The result is a less than smooth rotation of the wheel and an accelerated degradation of your bicycle’s hubs, with a worth case scenario of replacing your wheels.
Any bike restoration I’ve undertaken necessitated the overhaul of the bicycle hubs. After 20 or more years of use without any significant maintenance the grease in the bearings dries out, water seeps in, corrosion occurs, and damaged is sustained.
Though ball bearings can be obtained easily enough, this is no longer the case with vintage hub cones. I recently went to my local bike shop and he no longer had cones in stock. And though they’re not the most expensive parts on your bike, knowing the right measurements and waiting for them to arrive can be a hassle.
Luckily pitted hub cones can be repaired easily enough with tools anybody probably has laying around.
Step 1. Removing the hub spindle
Since the bearing race of the cone is located inside the wheel hub, you’ll need to disassemble it to reach it. I’ve written an article about this particular procedure. You don’t need a special tool besides a spanner wrench to disassemble the hub. Tightening the cone when you’re done however, necessitates a special cone wrench to do so.
Step 2. Sanding the pitted hub cones
Removing the pits from the cones is done by sanding them while the axle rotates. I place a standard drill in a workmate (you can also use a vice) and place the axle with the cone in it. The cone is as close to the drill’s opening so it doesn’t wobble while rotating. And I also tighten the cone just as you would when overhauling your bicycle hub.
I start with an 80 grit sandpaper and go all the way up to 1200. If you want to be able to apply more pressure you can fold the sandpaper around a screwdriver. Apply force to the side of the cone so you don’t press the drill out of the workmate.
Don’t over-sand the cone. You’ll affect its shape if you do, and its ability to seal off the hub. And sanding any type of metal usually removes its hardened surface, decreasing its ability to prevent corrosion in the future. So performing such an operation is a trade-off to a certain extend.
And that’s how you repair damaged and pitted hub cones ! If you like this article give it a thumbs up. If you have any questions or suggestions for new articles, let me know in the comments below. Cheers.
Q: My race (cup) is corroded. Do i need to do this as well as the cone?
A: Yes, but you can’t use this setup obviously. You’ll need a dremel tool to smoothen a bearing race.