Bicycle Mechanics - Axle on sealed hub

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pyze-guy
07-17-04, 11:17 PM
I picked up a built Mavic x517 with a single speed axiom sealed bearing disc hub today. How, if at all, do you remove the axle?


sch
07-18-04, 06:53 PM
Not sure why you would want to, doubt if any parts, except the bearings themselves
are available. If that is you thought, replacing the bearings then you should be able
to press them out using a tube that fits over the axle and is the same size as the inner race of the bearing and placing in a press extrude the axle. Alternative would
be to use a tube larger than the outer race and extrude the axle + the attached bearing on one side. This might destroy the bearing, it depends on whether the bearings seat against a step on the axle or whether the axle has the same diameter from one end to the other and the bearings sit on a tight spot in the axle. If the bearings are smooth and have no end play (side to side wiggle) or radial play (wiggle
up and down in the direction of the spokes) you need not do anything. If they are a bit gritty and have plastic seals, it is not hard to pop the seals in and out to clean and regrease the bearings. Measure the amount the axle sticks out on each side beyond the bearing before pushing if you feel it is necessary to do so. Steve

BMXTRIX
07-19-04, 08:40 AM
For BMX at least, sealed bearing hubs you simply push the axle out. You may need to tap on one end of the axle with a hammer to get it to pop, but the axle is machined with races for the bearings to sit directly on. When you tap on the axle (after all nuts are removed from the outside) the race that the bearing sits on will push that bearing right out of the hub with no problem.

I have never seen a bearing damaged by this, and BMX riders (street especially) may break axles as often as once every month or two. This is the norm for removing sealed bearings are popping the axle out of a sealed hub.

If you are worried about your axle, then put a wooden board between the hammer and the axle to protect the surface of the axle from impact.


sch
07-19-04, 04:05 PM
For BMX hubs that makes sense. I wasn't sure 517 rims were made in BMX size.
For that sort of hub, leaving the nut on and screwed 1-2 threads outboard of the
end of the axle would give a good pressure surface to push on. A hammer would
work at greater risk to the bearings and axle. Steve

pyze-guy
07-19-04, 11:28 PM
For BMX hubs that makes sense. I wasn't sure 517 rims were made in BMX size.
For that sort of hub, leaving the nut on and screwed 1-2 threads outboard of the
end of the axle would give a good pressure surface to push on. A hammer would
work at greater risk to the bearings and axle. Steve


Thanks for the help. I ride a mtb, removed the disc and bolted a cog on to run a flip-flop s/s fixie. The axle is chewed up and I was curious to how to get it out so I didn't bust the hub. Thanks guys.