Hey guys....

Do you really need a Thrust Bearing? My motor shaft is 5mm but the thrust bearings off OSE and FE are over $20 shipped....

Can you simply use any 5mm inner diameter bearing?

As long as the thrust bearing is made out of a good metal IMO(cuz they go under a LOT of stress), and the outer diameter will fit on the shaft hole in the motor mount, cuz some mounts have fairly big shaft holes like in the pic.
What I did to that problem is I put a small metal plate on the front of the mount and carefully drilled holes for the mounting screws and the shaft to go through. The shaft hole was small enough for a shaft to go through and a bearing to fit on.

Thrust bearings are not absolutely needed, but they can really save the life of the motor bearings. Also if it's set up right, it can reduce the damage from a an accident where the motor endbell pops off.

I personally wouldn't run a motor without a thrust bearing. Like Bob said there is a lot of force on the end bell of a motor without one and to have a end bell pop off is pretty bad and will most likely kill your ESC too. On my Fiegao and hacker motors I like to put the thrust bearing up against the motor but with the Neu style motors with the longer shafts I build my mounts so that the bearing is up against the mount itself. You will be happy you spent the $20 at OSE on the thrust washer after you lose one end bell on a motor.

thrust bearings make your motor live longer. run more efficent and keep the armature bearings in decent order for longer.
def. get one or 5

Yes! You really need a thrust bearing.

Today I ran my E1 Hydro at a race and my thrust bearing blew up literally. The motors end bell is now damaged and this was only 1/2 a run.

Ryan

heck yeah.