Possible gearing combos?

[TITANIUM94010]

What's the highest possible gearing for the 10.2 tranny with the 56t spur? I don't need to use to max gearing, just a good idea of what gears I can use In between.

I'm aiming for 20ish mph with a Castle slate 2850kv motor

[Crunch]

Here is the axial transmission guide: Axial Racing - Axial Transmission Guide

[TITANIUM94010]

I did some calculations, I would need a 30t pinion to acheive the speed I want, which is far too much for a 32 pitch gear, so I'll have to get a smaller spur. What other spur gears fit the 10.2?

[TheLetterJ]

Are you talking about the "kit" tranny, or the plastic 3 gear? If just a 3 gear, you might want to take a look at SSD's high ratio trans kit. It is 1.8:1 as opposed to the standard 3 gear at 2.6:1 HRT KIT I ran that with 20/54 and that was the highest I ever tried. I had to grind the slots in the motor mount outwards to even fit that, but if you were to start with a smaller spur you'd have room for an even bigger pinion. Still, it was pretty quick with 3400kv on 4s... calculated 55mph on that setup, never actually saw over 40mph though. Punch some numbers in here: https://scriptasylum.com/rc_speed/top_speed.html

[TITANIUM94010]

Originally Posted by TheLetterJ

Are you talking about the "kit" tranny, or the plastic 3 gear? If just a 3 gear, you might want to take a look at SSD's high ratio trans kit. It is 1.8:1 as opposed to the standard 3 gear at 2.6:1 HRT KIT I ran that with 20/54 and that was the highest I ever tried. I had to grind the slots in the motor mount outwards to even fit that, but if you were to start with a smaller spur you'd have room for an even bigger pinion. Still, it was pretty quick with 3400kv on 4s... calculated 55mph on that setup, never actually saw over 40mph though. Punch some numbers in here: https://scriptasylum.com/rc_speed/top_speed.html

I think the transmission that comes with the SCX10.2 raw builders kit is the 3 gear, I'll see...

Edit: It's 60 dollars though, I'd be better off using the TRX4 tranny. but thanks for the help!