brian's gearing calc...
 

does everyone use the 4.2v per cell rating or the nominal 3.7v?
i gear for 40mph like a lot of other people but i use the peak voltage of the battery, 4.2v per cell.

what does everyone else use?
maby this is why i have suck unusually low temps?

I use 3.7v/cell for all of my calculations.

3.7v here too. If you go by 4.2v, then your actual speed will be slightly slower (or alot slower, depends on how good the batts are really), but it also means you are geared lower so hence the lower temps really. I never really factor in tires ballooning, if I did then I would be geared lower again too, meaning lower temps and roughly the same speed as I originally geared for once you add in the ballooning.