Need help! 5mm 48p pinion for Pro4 in Scx10

[jeepnvinny]

So I just picked up a Pro4 3300kv motor for my Scx10 Dingo. The Pro4 requires a 5mm pinion. My Scx10 has the RR AX10 Slipper Unit 88T Spur... So I need a 5mm 48p pinion to match the Pro4 and 48p 88t spur gear.
My question is: What tooth count should I consider for the pinion? I can pick up a 5mm 48p 21t pinion today, but should I wait to get a 17t or 19t pinion? (Robinson Racing only has 17t, 19t, 21t, and so on)
88/21=4.19:1
88/19=4.63:1
88/17=5.19:1

[k7zpj]

First of all, I would switch to 32p gears with a Pro4 3300kv so that you are not stripping spur gears all the time. I would start with 56/12 and go from there. You can use a Duratrax # DTXC9397 spur and the 5mm RRP pinions.

The Pro4 is a lot of motor for a SCX10 so you are going to be upgrading a lot of parts due breakage.

[Meatwad]

I agree with going 32p, definitely more robust.

But if you must, these are the only 5mm bore 48p pinions I've ever seen: Kershaw Designs - 48P Pinions

Edit: These are probably RRP pinions now that I see they start at 17t as you mentioned...

[jeepnvinny]

It is a lot of motor for an scx10 lol... The the rig is pretty well built. As far as the spur gear, it is metal, and I don't plan to beat the snot out of it. But if I did go with a 32p spur, I probably need to eliminate the slipper unit as the RR AX10 Slipper Unit wouldn't be compatible with the new spur. Thoughts?

[new2rocks]

You definitely need to go with a 32p spur. I ran 48p with a ROC 412 3100 on 3s on 2 rigs and had a hard time getting more than 2 packs (6 hrs runtime) out of a pinion. Since switching to 32p, I have yet to strip a pinion in 15+ hrs of runtime on each rig. The RRP 56t 32p slipper for the Slash works, though you will probably need to shim a bit to create enough clearance with the motor plate and you'll need an extra spacer on the shaft to lock the spring down fully. I've run anywhere from 9-12t on the pinion. It's a great setup.

[Meatwad]

Its not too much motor for the truck, per se, I'm running one as well. Its just too much for 48p

A plastic 32p spur can be adapted to the stock axial slipper, although IIRC the RRP scorpion one is a bit tougher. The slash4x4 32p slipper/spur and beefy topshaft is a badass combo.