Gearing starting point RB5 SP2

[carlin]

Hi Guys,

I be honest but I don't understand all this gearing balls tbh find it little confusing.

Right I'm going to be running 10.5t motor in my RB5 SP2 for indoors as the track is pretty small.

Was wondering what gearing is good starting point.

I have run 27t pin on the 7.5t V3 SP was brilliant outdoors.

But I have been told to run or start on 25t pinion?
It will be 10.5t V3 SP motor & I know always been told they prefer a higher gearing

Any help would be grateful

Thanks