Maintaining the reliability and life of your bicycle’s hub bearings can be a process that is more involved than you might think. Therefore, it’s important to know how to service bike hub bearings correctly to get the most out of them and keep them performing properly.
When a bicycle is in need of servicing, typically it is due to the bad condition of the drivetrain or the wheelset. One of the most often overlooked items is the bike’s hub bearings. Not properly servicing the bearings can lead to an unsafe ride, corrosion and expensive repairs.
The first step in properly servicing bike hub bearings is to determine their type. The two main types of bicycle hub bearings are cup and cone and sealed cartwheel (aka cartridge) bearings. Cup and cone bearings are mostly used on applications such as BMX and mountain bikes, and require a slightly more detailed service. Sealed cartwheel bearings are usually found on high-end road bikes and are quick and easy to service.
If servicing cup and cone bearings, it is important to remove the hub from the frame. Next, the axle needs to be unscrewed or popped out of the hub. Once the axle is removed, carefully remove the bearings and place them in a cup of warm water to loosen any caked-on dirt and grease. After that, use a small brush to remove any dirt or grime built up on the bearings.
Now, take the axle and measure its diameter at the center. Measure the bearing cup and cone side for similarities with the axle. This helps to identify if any of the parts need to be replaced. If necessary, take other measurements to be sure that the replacement part is an exact fit.
Once you have determined the parts need to be replaced, you can then install the new parts. If dealing with cup and cone bearings, it is often a good idea to use fresh grease before inserting them into the hub shell. Then, screw the axle into the hub shell, and tighten to the suggested torque specification. Make sure both sides have equal torque.
For sealed cartwheel bearings, the process is much simpler. This type of hub does not usually require disassembly to install fresh grease or to replace bearings. Instead, simply unscrew the bearings caps, replace as necessary, and put everything back together.
Though servicing bike hub bearings can seem complicated, it is a crucial step in keeping your bicycle safe and performing properly. With the right tools and a bit of patience, you can easily service your bike hub bearings and have your bicycle ride like new.