When it comes to grease, use it like you have an endless supply. Keeping the bearings lubricated with an amble amount of grease can extend the life of them. This simple task will make them last longer and in the long run it will be cheaper.
Most new bikes come with grease on the bearings, but normally it is not a sufficient amount. While the bike is still brand new, we like to take it apart and add additional grease to the steering head, wheels, linkage, and swingarm bearings. My #1 rule of thumb is, anything that makes parts last longer, is worth it.
Bearings are a moving part with lots of friction. Think about the times you’ve ridden your bike in sand, mud, water, and other outside elements…that’s like every time you ride, right? Packing the bearings with waterproof grease protects the bearings from the elements and can also reduce the amount of friction. Not enough grease will allow water and dirt into the bearings, which will make it go bad fast!!
Check the bearings often. Every time you prep the bike for a race, check for free play by spinning, twisting, or agitate each part side to side to feel for notches, restricted movement or excessive free play.
Failure to replace wheel bearings when needed or keeping them greased can result in needing to replace the hub. That can be costly so be sure to keep an eye on it. Your bike have linkage suspension? Be sure to check that often otherwise your rear suspension can seize up. Swingarm bearings gone bad can also affect how the bike handles in the rear.
Point is, do not be afraid to put some good waterproof grease on the bearings.. A LOT OF IT!