gearing ...
 

Hi, guys possible I got a noticeable runtime down from 87t spur to 84t ?

I doubt it.

would help if we had a setup, motor esc batts, maybe the vehicle its in...


could be undergeared- could be over geared- fixing either can ad runtime as the motor is more efficient

vehicle : hpi e-firestorm 1/10 2wd stadium truck
motor : traxxas velineon 3500kv
esc : mamba max 1/10
gearing : 18t pinion / 84t spur
battery : 2s lipo 7.4v 5000mah

I want to try to get a good 20 to 25min of runtime from my setup ...

Without knowing the diff and tranny ratios, I couldnt figure it out using the calcualtor- that said, a change of only 3 teeth on the spur wont make anything more than a tiny difference. What are your esc/batt/motor temps typically?

I remember reading an article on gearing somewhere a while back, and although not completely precise it eluded to basically a 4T change in the spur being = to a 1T change in the pinion. It's an approx good rule of thumb.