Jan 2018 – Mikes Blog

Having to replace my wheel bearings in my Fulcrum Quattro wheels, I thought I’d just take a quick post on the process.

Front wheel

The front wheel, is of course the easiest of the pair todo.

1. Remove end caps. These just pull out, but can be an absolute arse to pull out.
2. Remove the tension collar, and the small metal washer that sits under it
3. Pull out the axle from the wheel.

Now, check the wheel spin, and look at the bearings. Check the space behind, and confirm you have room to drive it out.

Place the wheel hub on a block of wood, and drift out the bearing from its seat. Do the same for the other side.

Give the bearing seat a good clean out with a degreaser rag.

Now, to reseat the bearings, I use a Rapid Racer bearing set. The two bearings used in the hubs are 6903 sized. So mount up the bearings in your press, grease them up, and gently drive them home until they stop. Don’t force them, just drive until they stop.

Clean off the axle, apply grease to the races and a small amount smeared over the rest of the axle and reassemble. Don’t forget the small metal washer under the locking ring.

Adjust the locking ring just enough to insure the axle dos’nt move side to side. Don’t over tighten.

Push the end caps back on (you can give the o rings on these a light grease coat, just to make them easier to remove in future)

And your done.

Rear Wheel.

On the rear wheel, it’s normally the left bearing that goes bad, as the right is well protected by the freehub, but its always a good idea to replace them all at the same time.

You’ll need a few extra tools for this wheel.

• 5mm Allen key
• 17mm spanner
• C-clip pliers.
• 6803 bearing press.
• Chain whip
• Lock ring tool
• Grease gun.

Start off by removing the cassette, and give the whole freehub a good wipe down. This is a dirty hub, so clean all the wheel as you have access to it.

Insert the 5mm Allen key into the non drive side, and the 17mm spanner onto the drive side.

The left hand end cap is standard thread, but damn tight. Once that caps off, remove the locking collar, and again mind the small metal washer.

Pull the full freehub and axel out of the wheel. The pawls should be quite secure on the freehub, but just be careful they don’t fall.

Now, using the worktop, insert the 5mm Allan key and use it against the worktop to stop the freehub moving as you apply torque from the 17mm spanner to remove the freehub nut. Remove the nut and the spacer behind it.

The axle should now pull out of the freehub.

Replace the hub shell bearings in the rear wheel the same as the front. These again, are size 6903 sized.

The fun start with the bearings in the freehub. 🙂

Make sure you have a rag nearby to clean up with, as this is messy.

First drift out the outer most bearing, you’ll need to push the metal sleeve to one side to get access for the drift. Once out, remove the metal sleeve and clean out the freehub shell of the horrible milky white grease. Look inside the freehub, and you’ll see the inner bearing, it is however secured by a c clip on the inner. So, remove that c clip with your pliers and you’ll be able to drive that bearing out of it’s initial race. Now ensure the bearing hasn’t flipped over in the hub and carefully drive it past the outer race too.

Give the whole shell and pawls a really good clean with degreaser, and leave to dry. While that’s drying off, clean your work station and other parts that are greasy.

Now that’s all clean and dry, get your bearing press ready. The freehub takes bearings that are 6803, so mount one up in the bearing and pregrease. Drive the first bearing down past the first bearing seat, and continue down until it is seated just under the groove the c clip sits in.

Add a little more grease to the bearing top, and insert the clip back into its seat and ensure its seated.

Now, grease it all up, add loads of grease into the freehub shell. Just add it in, don’t skimp.

Reinsert the metal spacer, and line up the outer bearing on your press. Two turns on the press, remove it and check the bearing, if it’s not quite flush, give it a quarter turn and check again.

Inject grease into the pawl seats. Some people don’t like grease in the pawls due to a belief it clogs up the pawls and causes them not to seat correctly. All I can say, is that I’ve never had and issue. But feel free to leave them with a light coat, or a heavy(ish) oil.

Reassemble the axle and end cap on the non drive side, place the freehub back onto the axle and secure it using the metal spacer and nut.

Test spin the wheel. It will feel a little draggy initially while the bearings wear in, and the grease distributes. If the hub is too loud, remove the freehub, and add some grease to the toothed ring. It’ll quieten down for a whole at least.

Make sure the end cap and freehub nut are tight, and clean up. Your done..