Pinion advice

[littlened]

I have a Lazer zx-5, and I want to put in a 4t brushless motor, which I'm going to restrict to around the same speed as a 10t brushed motor for racing. My question is, what pinion should I use to go with the 76t spur already fitted to the car?

I currently have a 24t pinion, but that's just on the stock motor.

[Col]

I assume it's an RTR?

[dibble34]

In both my zx5 and zx5 rtr i ran a 4.5 brushless with a 16 tooth pinion

[littlened]

In both my zx5 and zx5 rtr i ran a 4.5 brushless with a 16 tooth pinion

What batteries were you using with that?

[blue_pinky]

Will running a 4t down to 10t speeds not run the motor VERY hot and damage it? Under gearing is pretty much as bad as over gearing as I understand it?

[littlened]

I'm not wanting to under gear it, I can use the ESC to limit the power to the motor, restricting it's speed.

[dibble34]

What batteries were you using with that?

NIMH, but good ones