WHICH BEARING TYPE & WHY?
One of the more common questions in RC is “which bearings should I use and why?” Considering all of the different types of bearings available, that can be a confusing decision. In the end, it all comes down to how the bearings are going to be used.
Metal shielded bearings provide less drag on the internal bearing components and therefore are the go-to choice for on-road RC cars such as touring, drift, drag, and even some off-road carpet track vehicles. For bashing, off-road, and all other dirt applications, it’s best to get bearings that have a rubber shield on at least one side. The rubber shield might drag a little on the internal bearing components, but it will help keep out dust, dirt, and debris much more effectively than a standard metal shield will. There’s nothing worse than a crunchy, locked up bearing, so rubber shielding is the way to go when dirt is involved.
STEEL VS CERAMIC BEARINGS
Most RC bearings are made from steel and contain steel balls and races, which are a great all-around choice due to their relatively low cost, good longevity, and wide availability. Steel bearings can also take a lot of abuse, and so long as they are thoroughly cleaned and maintained when needed they will last a long time. Ceramic RC bearings contain ceramic balls with steel races and are ideal for high performance applications. Ceramic bearings tend to require more regular maintenance and are usually more expensive than their steel counterparts.
So why would we want more expensive ceramic bearings? It’s all about the performance. The ceramic balls used in RC bearings are made from silicon nitride, which is lighter and harder than steel. This lightness and added hardness make them ideal for high-speed performance applications like on-road touring and drag racing. Ceramic bearings are also used in high-performance nitro engines since the ceramic material copes well with the extreme RPMS and high heat.
The extra hardness of ceramic bearing balls has sparked debate on whether they should be used in off-road applications, since the extremely hard ceramic might not take impacts as well as steel in something like a hub or axle bearing. Considering ceramic bearings have been used in off-road RC applications for years with much success, I don’t see a downside to them so ultimately, it’s personal preference. A widely agreed upon mindset for offroad applications is to use ceramic bearings in the drivetrain and steel bearings around the axles, giving you the best of both worlds.