Originally Posted by A. Rhodes
I said as a general rule, not as an exact to keep roll out perfect. I was given the 1 tooth per mm by two local racers at my track, but what do they know, they only TQ'd & won Snowbirds
Well, if we take it to the extreme, and assume a 53mm tire being trued down to 52mm and start with a large pinion like a 38, we get closer to the rule of thumb working.
On the other hand, I'd much rather TQ Snowbirds than be some keyboard jockey with a calculator, so I defer to their greater experience!