You are hereForums / By Discipline / Mountain (off road) / MTB Gear / how to check/replace remove wheel bearings??

how to check/replace remove wheel bearings??

Alex's picture

By Alex - Posted on 06 April 2008

anyone know how to pull out wheel bearings (specifically on bontrager big earl wheels/hubs) as mine are screwed already, and cant find for the life of me where they are/ are taken out..they are sealed bearings if that helps at all?? or do i just need new hubs?

Rob's picture

Last time I got rear wheel bearings changed the part cost 20 bucks and the LBS fitted 'em for another 15. Can't go wrong. Mind you - it was a XC wheel, maybe these 'big earl' things are more 'spensive.

That said, I went looking on the ParkTool site which has a page on hubs and stuff. Oh, it says,


These types of hubs use an industrial type-bearing unit. The inner and outer rotating races and ball bearings are installed as a unit. These hubs are not serviceable in the sense they are overhauled and adjusted. When the cartridge bearings are worn, rough, or have play, the cartridge should be replaced. The bearing unit is then removed and a new one pressed in. This requires special tools and is best left to professional mechanics.

Alex's picture

aha thanks rob! yeh i prob best take to the old lbs, just thought id have a looksy myself if poss, amazing how badly my front has seized up for a rather $$ big earl sealed bearing under a year old, but there u go..

dez_b's picture

bearings , Hay Alex I have replaced a few on my bikes pretty easy just tapped them out with the appropriate sized timber dowel rod then took them down to ABC bearings in Brooky they measured them and only cost me aprox $20 cleaned the axle light grease then tapped them back in .(buy some extras for the next time ask for the best quality) My hub was using 20mmx32mmx7mm part # 68042RS sealed bearings and I am assuming all 20 mm axles would be pretty standard .
Removing them the first time feels a bit sketchy just support your wheel on a solid table with the axle hanging over the edge and the tyre supported on the dinning room chair (not when the missus is at home) and insert the dowel through to the opposite side tapping around the outside of the bearing to dislodge it then centre too punch it out straight, when the bearing falls out flip the wheel over and the second one is easier . Take note of where the bearing sits in the axle before so when you put the replacement ones in they sit flush with the axle as the original.
its a cake walk
20 mm Axle maintenance : after riding through water when I get home I take my front axle out and clean it and lightly grease it then wipe any excess off , if you leave it wet eventually you will notice two rust marks on the axle as water sits in the bearing flange (sealed bearings are not fully sealed) eventually shortening the life of the bearing.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Best Mountain Bike