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Dirt Rag Fresh Dirt
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3.1.2006
Tech Tip 34-A: How to extract a stuck bearing race from a sealed bearing hub.
By: Brad Quartuccio
 Sealed bearing hubs are wonderfully easy to rebuild – remove the axle, tap out the old bearings, push in some new ones, replace axle. Done. Like most people, I tap the bearings out with the end of the axle or an old screwdriver and a hammer. Preferably the screw driver and hammer, as we go back a long while and don't get to hang out like we used to.
Late last week I finally decided to rebuild a long neglected Surly rear hub that's bearings turned to dust years ago. With screwdriver and hammer in hand, I went to break the first bearing out of its rusty cage – and out came its innards rather than the whole cartridge unit. This left nothing but a bearing race stuck in the hub shell with no obvious way to extract it. No shoulder to tap on, nothing to grab hold of. Can't cut it out – bearing races are hardened steel, much harder than the aluminum hubshell. In the words of pisans everywhere, "Somanabitch."
So I called in reinforcements. Karen and I examined the hub and tried a few methods of extraction with not even a hint of success. Ms. Brooks uttered something about a star nut, and then a plan came together. Find a star nut that just fit into the bearing race, and see if we could tap it into the small concave section where the balls used to roll. With star nut in place, we'd be able to tap the race out. Don't push the star nut in too deep, or it will get lodged in the hubshell. At this point, a risk I was willing to take as a hub with part of a cartridge bearing stuck in it wasn't helping anything.
Problem solved. First try was able to tap a 1" star nut into the bearing race, but not through it. Threaded a bolt in, tapped it out with the end of the axle. Hub saved.
Moral of the story: I dodged a bullet that almost cost me a new rear wheel. Service bearings more regularly, and the cartridge won't seize into the hubshell as mine did.
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