A smooth ride on any bicycle requires properly maintained hubs, which are the axis points of each wheel. Although highly important to the function of the bicycle, hubs are mechanically very simple. They consist of only an axle rod, ball bearings and sealing caps. Over time, these bearings can erode and the grease used to lubricate them can become a slow, dirty sludge. When this happens, repair of the bearing race or replacement of the ball bearings is necessary.
- Skill level:
Things you need
- Chain whip
- Large adjustable spanner wrench
- Cassette removal tool (Shimano type)
- Flathead screwdriver
- Cone spanners (13mm, 15mm and 17mm)
- Socket wrench
- Plastic pen top
- Plastic container for parts
- Bicycle grease
- New ball bearings
Remove the rear wheel using the quick-release lever or an adjustable spanner wrench.
Remove the gear cassette from the drive side of the wheel. Place the chain whip around one of the larger cogs and fit the Shimano-specific removal tool into the grooves near the smallest cog. Grip the removal tool with a large adjustable spanner wrench and turn counter-clockwise until the cassette can be removed by hand.
Lay the wheel on its drive side and pry the sealing cap away with the tip of a flathead screwdriver. Carefully insert the corner of the tip into the seam and use leverage to lift up the cap. This will allow access to both the bearing races and the cones.
Hold the cone in place with a 15mm spanner. Use a socket wrench to loosen and remove the nut at the top of the axle rod. Leave the cone assembly in place.
Flip the wheel vertically and pull the axle away from the drive side. Use the plastic top of a pen to slowly remove the ball bearings from their old bed of grease. Place them into a small plastic container.
Repeat Step 4 for the non-drive side of the wheel.
Clean all of the old grease from the bearing races with degreaser, tissues and cotton buds. Also clean the cones on either side of the axle assembly.
Start from the non-drive side and place new ball bearings into the bearing race. Coat them with a liberal amount of fresh bicycle grease. Repeat this step for the drive-side of the wheel.
Begin from the drive side and snug the cones down to the bearings, but not so tight that there will be excess friction. Hold the cones in place with a correctly sized spanner and use a socket wrench to tighten the securing nut.
Replace the gear cassette onto the drive side of the wheel.
Install the wheel and give it a test spin. If there is noticeable friction, back the cone away from the bearing race with a cone spanner. Fine adjustments of this nature should be made from the non-drive side.
Tips and warnings
- The freehub body (underneath the gear cassette) does not need to be removed for the servicing of a hub. However, you can remove it for cleaning purposes using a 10mm Allen wrench if you wish.
- This guide explains how to repair a rear Shimano hub. The process is identical for the front hub with the exception of removing the gear cassette.
- Ensure that the rear hub is properly assembled before taking your bicycle on a test ride. Improper reassembly can result in mechanical failure or accident.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for