5/16/15 5:33 PM

Front hub bearings got roughed up in my crash.

I have a proper blind-hole bearing puller but still can't get the damn things out. The gap between the hub shell and the backside of the bearing is <1mm, not enough room for the puller's lip to nestle in and get a good purchase. Even cranked tight with a wrench, it slips after a couple taps.

The ID of the shell is same 8mm for bearing, so with the small gap and narrow opening there's no way to get a punch in there from the opposite end.

Suggestions?! The bearings are getting replaced, so damage to the shell is all I need to avoid.

5/16/15 6:07 PM

Are they angular contact cartidges or the more common symmetrical type? If they are symmetrical, you can pry out the rubber seal and then lift out the metal bit that holds the bearings equally spaced. Push all the bearings to one side and then pull out the center race of the bearing and then the balls. The outer race should be a larger ID on the centerline than it is on the faces. Assuming it's adjustable, you should be able to get your bearing puller clamped firmly into the center of the outer race and then tap it out. At the very least the outer race is probably more "dremel-able" and you could machine a lip into it and then use your puller again.

If they are angular contact there's likely not much to pull against on the outer race.

Or I'd sacrifice a flat blade screw drive, bend over the very end and machine it down so that it fits into the space where you're trying to grip on with your bearing puller, insert it from the opposite side and then wedge it into that gap with a tapered piece of -----? (wood maybe? a large taper punch if you have one?) then give it a good, solid wack with a hammer, move the screw driver to the opposite side of the bearing and repeat. You may knock the screw driver out of the groove each time but as long as the bearing moves a bit you're making progress. And you don't need to move it much until you can get your bearing puller back in there again.

This is the best I can suggest without pictures or having it in my hands.

5/16/15 6:53 PM

Pull the axle and tap them out with a brass punch from the opposite side. The brass punch won't hurt the other metals and will bite the inner race from the inside. I supported my hub with a roll of duct tape. The bearing just dropped right out by using little taps with a hammer going around the inner race. Just tiny taps or you can cock the bearing and then it will really be stuck.

If there is no lip at all. Then try carefully using an awl. I have never seen a hub with the diameters matching.

5/16/15 7:17 PM

- there is no axle to remove, just threaded end-caps. the hub shell's ID is 8mm.
- the ID of the bearings is the same ID of the hub shell, so not alot of space to fit any sort of tool.
- if you could fit a punch into that skinny space, there is effectively no gap between the bearing and the hub shell for a punch to do it's punching.

honestly, i need a headset cup removal tool, but sized for 8mm headsets! the spring-loaded prongs would be perfect for this application.

<img src="http://brown-snout.com/cycling/tech/hub-bearing-removal.png">
<img src="http://ecx.images-amazon.com/images/I/41i22ig2PFL.jpg">

Last edited by walter on 5/16/15 7:52 PM; edited 2 times in total

5/16/15 7:36 PM

clamps to the inside of the bearing (similar to my puller, but doesnt require a lip).

once fitted it allows use of a skinny punch, and the punching action acts on the wedge, so the force makes the extractor grab the bearing more tightly.

<img src="http://wheelsmfg.com/media/catalog/product/cache/1/image/598x598/06866988214b6a9b717ef7211319fd38/6/0/608-ext_2.jpg">

5/17/15 4:17 AM

That is an odd design.

Who is the hub manufacturer?

5/17/15 8:20 AM

they're sold under the "superlight" brand by bikehubstore.

once i get these bearings out i may remove a little material from the hub shell so it's easier to get purchase on the bearing next time.

5/17/15 11:16 AM

Make sure that hub shell isn't tweaked. These are way light as you are aware. I have the one I got from you and another one on the road now and quite happy with how they spin too.

The Pacenti SL23 Wheels I built with that front hub and Bike Hub Store's SL210 rear hub with lasers/AL nips except trailing drive side 14/15 brass nips is crazy light wheelset 28spoke f/r.

5/18/15 5:33 AM

The shells are typically quite thin and there's usually a tubular spacer that fits between the bearings. It's held captive by pressure from the bearings, but you may be able to pry it off-center enough to be able to punch out a bearing. Once one's out, the other is easy.

5/18/15 8:55 AM

and it does make sense, you'd need something to take the lateral pre-load. the ends of the assumed spacer are threaded to accept the end-caps.

i'll just wait until the extractor arrives rather than beat up the hub. it's not like this is holding up my ride plans!

Last edited by walter on 5/18/15 1:16 PM; edited 1 time in total

5/18/15 12:13 PM

I am pretty sure my Ch. Carbon wheels use that same hub. You are rights, they spin well but now I dread when I need to replace the bearings. At least you will have the experience and can talk me through your issues.

My Fulcrum hubs had just enough of a lip to tap the bearing out from the opposite side.

5/18/15 6:10 PM

apparently you can remove the bearings by (gently) using the end-cap as a drift to get started.

remove one cap, but the other only loosen 2 turns. gently rap the cap with a rubber mallet to scoot the bearing out a bit, 2 more turns and repeat, 2 more turns, bearing should be extracted.

with one out, getting the other one out is easy using a 1/2" wooden dowel and the mallet.

5/19/15 5:15 AM

Yes, I forgot that the "spacer" is actually shoulders on the axle on those hubs. Using the axle as a punch is the key. I've been playing with thru axle hubs lately (MTB & fat bike) and was thinking about how they work. Sorry for the confusion.

5/19/15 10:57 AM

I was going to mention I thought there might be a center ridge on the axle just for the purpose....

5/19/15 12:49 PM

alternatively whacking either end-cap with a heavy hammer and piece of wood...it didnt budge, not a millimeter.

hmmmm....

5/23/15 7:57 AM

the aforementioned "wedge type" extractor plus some *very* heavy hammer strikes did the trick. enough force was used that the edge of the hub shell resting on the jaws of my bench-vise was slightly marfed/deformed.

there was not a hint of grease anywhere in the hub-shell, hence the extraction difficulties. one OEM bearing felt fine, the other was completely devoid of grease as well.