[glassdoctor]

You have to try it and see... the speed may or may not actually go down. That depends on whether the motor is revving all the way out with the 20. Sometimes speed actually increases if you drop a tooth or two.

I think I was running a 19t in my T4.... not sure how the gear ratios of the trucks compare. I'm sure you are close at 20 but you should try going down 1 or 2 teeth and see what it's like. Gears are only $3 and take 60 seconds to change. ;)

For what it's worth, imo the MM can handle overgearing a little. I run my 4600 with a 24t pinion in my buggy.