These bearings are a must if your rules allow for it when racing a tt01. these bearings will make your car much faster,smoother and have a much higher top speed and alot more acceleration. the plastic bearings have alot of friction in them and melt if you try to upgrade to a higher speed motor than a standard one.
this is the first upgrade you should make in a tt01 i think before you even build the car up and just leave out the plastic ones.
these are at a great price for such a huge performance increase and are worth every cent especially when racing a tt01 or df02.