I use white lightning grease. You can check with motorcycle shops for this. Prior to that, I used lithium grease like i8tweety.

Some guys use vaseline but this breaks down fairly fast. But the guys that use it rebuilds before every race, so this is not a problem with them. For me, if I don't have the time to rebuild before a race, I can let it go for the next race and the white lightning or lithium held up.