Bottom brackets are very important parts of a bike. If you forget to check them frequently, you may experience some problems especially when pedaling. Again, they may cause creaks if you do not remove the dirt that accumulates around that area. In this guide, we shall take you through on how to take care of these units.
Greasing
- Greasing the bottom bracket bearings is one of the most important things you should do to boost the durability of your BB. This is very important for those who ride frequently in wet areas. When doing this, you do not need to remove the bottom bracket. However, you can remove the BB threads when re-greasing.
- If you are using a press fit BB, you will find that it has an outer seal that protects the bearing. This means that you will need to remove the dust seals when greasing or cleaning.
- When removing the dust seal, you should put a small flat blade screwdriver below the dust seal.
- Work on the bottom bracket carefully when removing the dust seal. Repeat this process until you have completely removed it from the bearings.
- In case you have a rubber dust seal, you should use a very sharp tool.
- After you have successfully removed the dust seal, the cartridge bearing will now be visible. Get rid of the seal that covers the cartridge bearing using a thin tool like razor. Ensure that you do not bend the seal when removing it.
- Now you can clean the bearing thoroughly after getting rid of the cartridge bearing seal.
- Apply a high quality grease on the bearing and then turn the bearing so that the grease can penetrate in the balls and race.
- Replace the seal on the cartridge bearing. You can do this by simply pressing it back using your hand.
- Before you replace the outer seal, you can grease the top of the cartridge bearing seal if you ride in wet environments. This will prevent water from penetrating the dust seal.
- Now you can replace the seal or the dust cover.
- In case the bearing has a rubber outer seal you should ensure that you have placed the seal on the groove cup.
How do I know it is time to replace the bottom bracket?
Bottom brackets are among the most durable components of a bike. However, once you start hearing some noise when pedaling or if the crank is wobbling, you may need to replace the bottom bracket.
Do bottom brackets wear out?
Just like other parts of the bike, bottom brackets also wear out due to various factors such as weather and riding condition. In case you realize that your BB is making some noise or you are not able to pedal comfortably, you may need to remove the bottom bracket and then apply some grease.
Which size of the bottom bracket should I choose?
Road bikes normally use threaded bottom brackets which has a measurement of 68 mm wide. However, if you have a cross country or trail mountain bike, you should go for a BB with a measurement of 73mm
Sources:
1.How do I know when to replace my bottom bracket? – Post by Bicycles Stack Exchange
2.How to replace a bottom bracket – Post by Cyclist
