Service A Bike Wheel’s Cup And Cone Front Hub
Count The Balls
Shake – or pick – out the remaining balls.
Clean all the loose parts and the cups inside the front hub. The front hub may have removable push-fit dust-covers that will come out to make cleaning inside easier.
Inspect The Bearing Surfaces
Check the surfaces – on the cones and inside the front hub-shell – where the balls run, for roughness or uneven wear. Worn cones can be replaced but if a hub is worn it may need to be scrapped.
Check the axle is straight by rolling it on a flat surface. If it’s bent it must be replaced.
Repack With New Balls
Pack the races in the front hub with new grease and press the same number of new balls – of exactly the same size – into the grease. Changing the balls prolongs the life of the other parts. If you’re not sure how many balls came out, or if you suspect that the front hub was packed with the wrong number of balls, fill a race with balls and then take one out. The balls need room to roll around.
Check the lock-nut and cone assembly still on the axle are locked tight.
Assemble the other side and adjust the front hub.
If you screw the cone and lock nut hand tight, then unscrew the cone against the lock nut to lock the bearing, the result is usually a well adjusted bearing.