Jockey Wheel Common Questions

When I removed my jockey wheels, I noticed that they’re not actually the same. One has a bearing, and the other doesn’t. Is it  the top or bottom one that has the bearing?

The one at the top has the bearing. The one at the bottom floats more

Do bigger jockey wheels make my bicycle ride faster?

the bigger ones will rotate slower, thus lower rolling resistance meaning a more efficient bicycle

Odd number of teeth or even number of teeth?

An odd number of teeth will mean they will alternate with that part of the chain  it comes into contact with. This is particularly true for the tension jockey wheel as the chain comes at it at an angle when at the extremes of the block.

What kind of lubrication should be applied to the bearings in the rear derailleur jockey wheels?

Take them apart, clean them and lube them with some teflon or white lithium grease. If you don’t want to take them apart and they don’t have seals simply squirt them with some spray teflon lube between the metal end plate and the plastic wheel. Not as great as cleaning them thoroughly but it should do the job.