FBM hooked us up with a bike to teach you basic repairs on. Thanks to them and here’s to you, hub adjustment and repair from the BMXperts.
The tools needed to rebuild your unsealed hub are very simple, making this a task even a beginning home mechanic can tackle with ease.
The best way to tell if your hub is out of adjustment is to lift your wheel off of the ground, front or rear and try and move it side to side. If there is play then your wheel is loose. If you feel your hub is too tight, spin your wheel and see if it rolls to an abrupt halt. You can also hold onto the fork leg or chainstay and feel for the bumpy sensation of straining bearings.
Remove the problem wheel from the bike.
Try and unthread the cones and lock nuts by hand first. Chances are if your hub slipped out of adjustment, something is loose and you may be able to save yourself a step.
If not, then you will need two wrenches, one to fit the outer lock nut and one cone wrench to fit the cone nut. Cone wrenches are cheap, can be found at any bike shop and are a “must have” for working on wheels, so if you don’t have one, pick one up.
When the lock nut breaks free, turn the wheel over in your hand, holding the axle in place and turn the lock nut and cone off to the top side. This will prevent any bearings from falling out and rolling away to parts unknown. You can then remove them and set them in a safe place.
When you are ready to pull the axle out, cup your hand under it so any bearings that roll out will fall into your hand. Now you can set all your bearings aside and clean them. Keep in mind; rear wheels may have a different amount of bearings on one side then the other, so it never hurts to count them as you remove them.
Unless you are replacing your axle, it is not necessary to remove the remaining cone and lock nut.
Clean any old grease out of your hub shell. Inspect for pitting or divots that are signs that your hubs time spent out of adjustment did more then rattle your nerves. This surface cannot be repaired or replaced, so excessive damage means it may be time for a new hub.
You will also want to clean and inspect your cone cuts for damage. While this surface is very tough to harm, too much time out of adjustment will ruin anything, including your bearings. Fortunately, these parts are all replaceable so if you do have damaged cones or bearings, replace them.
Put a fresh coat of bearing grease in one side of your hub. Pack your bearings back into the hub race where the grease will hold them in place.
Check to make sure they are all properly seated and evenly spaced before installing the axle so the cone and dust shield will hold the bearings in place.
Now you can push grease into the other race and pack the bearings on that side. The axle will keep the bearings from falling into the hub shell and help you properly align them.
Thread your remaining cone nut and lock nut onto the axle and down onto the bearings. I this is a rear wheel, you may also have a spacer to replace which will go directly between the cone and lock nut.
Using the cone wrench, adjust your bearing tension by tightening the cone nut while holding onto the opposite side of the axle. When the tension feels right, hold the cone in place with the cone wrench and turn the lock nut securely into it to hold your adjustment.
Check your adjustment one more time by hand. If it feels tight or loose, loosen the lock nut on the same side you have been working on, make any necessary micro adjustments and retighten your lock nut. Don’t worry, even the best mechanics may have to do this once or twice to achieve the perfect adjustment, but that’s what separates a good mechanic from a bad one, the good mechanic takes the time t do the job right and rolls faster as a result. Happy hub adjustments.