Bearings have 4 main types of shields. Metal. rubber, teflon, and ceramic:
Metal-This is the cheapest bearing and the seal does a poor job of keeping dirt out. Best for onroad purposes as you will be cleaning regularly to keep dirt out. Also commonly found in clutch bells for nitros.
Rubber- Restricts bearing movement and spin. However, the rubber shields protect the bearing from dirt. This makes up for the metal bearing’s in ability to protect the inner part of the bearing. This is ideal for offroad though there is speed consequences. Best used for casual racing or RTR kits over the reduced performance.
Teflon- Work great for racers and those who want performance. They block dirt and spin very free. They are like the best of the metal and rubber worlds. The difference between teflon and ceramic is cost, ability to seal, and while teflon offers greater heat resistance over metal and rubber it is rivaled by ceramic’s ability.
Ceramic- Most costly. However, it offers a better longevity and also heat resistance over the teflon. Offers the best spinning ability and also blockage to dirt. These are the most expensive but the best out there. Hardcore racers, and Squirrel, strive for these and then teflon if not available.
What about the balls?
The two types of balls are typically chrome and stainless. The biggest differences are cost and ability to withstand corrosion. If you clean your bearings and keep them lubricated the the difference is minimal as the lubrication will withstand corrosion. Chrome is slightly less expensive and can corrode a little easier. Again, keep your boys clean and lubed and the difference is minimal.
Typically, this is a standard that represents the shields and balls used in the bearing. This is a symbol (or easily recognized way of) showing what the bearing comprises of. The color of the seal means nothing.
Cannt have a Squirrel write up with a vid… now can we???
This is off of the S4 vid series. The great part about this is that it shows a 2mph increase from going from a rubber bearing to a ceramic. It shows it on a radar gun and also the wheels spinning.
then there is a radar gunned speed test with stock rubber
6:00 ceramic test
then there is a radar gunned speed test on part 2 of the series:
That vid shows the install and then the speed test.