Bike hubs

Hub adjustments or overhauls can be difficult business. It is recommended if you are inexperienced in hub maintenance to start on the front hub. Without the complexities of drive train components as with the rear hub, front hubs are much simpler.

Some tools you need are:

• Cone wrenches
• Lockring removal tool (for rear)
• Bench vise
• Open-end or adjustable wrenches
• Small magnet
• Grease
• Wire ties
• Solvent
• Rags

Start by removing the wheel from the frame dropouts. On the rear hub, remove the cogs, and record the number of threads visible. It will be important later that the axle isn't exposed beyond the frame dropouts.

Secure the wheel in the vise. This may sound trivial, but it's always important to see what you're working on, and you save a lot of time when the wheel doesn't roll all over the workbench.

On the rear hub, remove the cogs and freewheel assembly now. 

Using the cone wrench in unison with the adjustable wrench loosen the locknut counter-clockwise until it comes off. Tie all washers and locknuts in the same order which they come off from the hub. Locknuts are different on each side of the hub, so keep everything separate and organized. This saves time during reassembly.

Unscrew the cone of the hub (counter-clockwise). This will let loose the bearings being held into place. Count all bearings on each side, and remove with a small magnet.

With the bearings extracted, you can inspect all components for flaws or signs of wear.

Inspect the cups and cones for bumps and roughness, and the ball bearings and races for pits. Replace anything that isn't shiny and smooth like a new baby's bottom. Bearings are replaceable, cups are not. If the cup is damaged, a new hub will be required. Sorry bro.

The easiest way to inspect the axle is to roll it around on the bench.  If it rolls flat, you're good.

Installation: You'll need a lot of grease. 

Start with the axle, including the threads.

Grease the hub shell cups and cones. After the ball bearings are pressed into place, cover them with grease too.

NOTE: According to Park Tool, common number of ball bearings is 9, 1/4" balls in the rear and 10, 3/16" balls in the front hub on each side. 

The easy thing to remember here is to reinstall everything in the same exact order as was removed. 

Install the right side first, the bearings, the cone, and the locknut fully,

Install the axle through the right side, and assemble the left side. The bearings, the cone, but leave the locknut loose at this time.

Tighten the cone down fully. Now back it off ever so slightly. This sets the bearings in place, but gives the hub an important amount of play that is eventually taken out when the wheel is installed.

Tighten the left locknut (clockwise).

For the rear, reinstall the freewheel, and then cogs.

At this point, you need to note that the axle is within the dropouts completely. When the nut is tightened on the axle, it's in everybody's best interest that it stays there. It needs to pinch into the frame, and if it's hanging too far out, it might not reach. This could mean the hub width is different or if you have a new axle, it needs to be grinded down a couple millimeters.

When you get the wheel installed in the frame properly, you should feel the new bearings spinning smooth as butter.