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My front wheel has started to wobble a bit at the hub and it's most noticeable when braking at the lights, as the front wheel is doing like a "pulsing" sound when braking - like as if the wheel is off center. I've pulled the hub apart, but I cannot see any obvious issues, yet when I lift the front wheel off the ground, as it's attached to the fork, the wheel slightly shakes when I tap it. It is not firm as it should be.

Because I cannot see obviously what's going on, could the bearings inside the sealed-cartridge have worn down in size? There is ample grease on them, but I guess even over time wheel bearings do wear down a micro-millimeter or two? That's the only explanation I have as to why the wheel hub has a slight wobble / shake.

Wheel is Campagnolo Vento-Reaction, about 5 years old now.

Here's a video of the wheel, showing how to get to the hub bearings...

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    Yes bearing can wear down. If you've pulled the bearing units out check for any play between the inner and outer races. – Argenti Apparatus Nov 20 '17 at 12:31
  • Age of the bike is only a second-order indicator of wear. Your distance covered is much more useful. Do consider keeping a log - I know my bike has just passed 9,520 km. – Criggie Nov 20 '17 at 20:14
  • You mention wobbling at the hub when braking, a strange way of saying the wheel is wobbling. How did you determine the wobble is in the hub? Are you sure it's not a rim irregularity, maybe due to broken spoke, or brake issue, e.g. contamination on the rotor? When you're off the bike can you lift the front wheel off the ground, grip the rim and push left to right (wrt the bike frame), and feel/ hear a thunk as the hub shifts around on the axel? Obviously you're also checked your quick release to make sure it's tight before doing this testing. – SSilk Nov 22 '17 at 15:22
  • @SSilk I know it's from the hub because, yes as you've stated, lifting the wheel off the ground and pushing left to right or right to left (ie: the shaking I mentioned) is possible - ie: it has movement. The wobble effect is happening because the front wheel does like a wobble/pinging sound, but that's not to do with the trueness of the wheel or the spokes. They are 100% tru, I've checked. The issue is definitely inside the hub, and as I suspect, the bearings are worn down, so I think a simple replacement of them will solve the entire issue. – Fandango68 Nov 22 '17 at 22:59
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The wheel in question uses sealed bearings. They are generally not serviceable. Service consists of replacement. You mentioned they appear to have plenty of grease on them. With a good bearing there should be grease in them and sealed in place by the seal. The only time grease will be visible is if the seal has failed. The seal usually fails because of bearing wear allowing movement.

  • I noticed the grease in them after lifting the seal, but by doing so has now deformed the seal plates. New bearings is the only solution to this. But just one side question: how do you pull out the sealed bearings? Are they meant to just fall off? I've figured out how to remove the springs, etc. Do I have to tap the axle to pop the lot out? The video above somehow skipped that crucial step – Fandango68 Nov 22 '17 at 23:01
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    Yes the typical method is to remove any retaining devices (not all hubs have them) and tap on the axle with a soft faced hammer. When inserting the bearing in to the wheel drive it with a socket with an OD the same or slightly smaller than the bearing. When inserting the bearing on to the axle drive it on with a socket that just fits over the axle. – mikes Nov 23 '17 at 0:08

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