Right m8 if u want fast acceleration stick with 19/61 if u want topspeed get the 25t pinion set and go for 25/55 i run around the middle 23/58 on a 17turn give good pullaway and top speed with no heat on the motor after a 30min run.
I havent tried any pinion under the standard 19t as theres more than enough torque and acceleration on the 19/61 setup but crap topend [

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55 has less teath so farthur apart and deflects small rocks and pebbels more easily due
and i aint got a clue wot carmans on about u shouldnt be getting stones or pebbles in the sealed pinion/spur box anyway LOL