gear chart or pinion advice for Losi JRX-Pro

[Tucsonan]

Ia there a good gearing guide for JRX-Pro builds with modern brushless motors?

I'm finishing work on my JRX-Pro and adding a 21.5 turn LRP motor with a Hobbywing XR10 JustStock esc. I haven't been able to find a good gearing guide for this combo. Based on the factory manual an old brushed 27 turn would take a 23 tooth pinion and 86 tooth spur gear. Absent any better info that's what I'll go with for the 21.5 turn brushless.

Thanks

[Dirtburner]

I'd say you'll be closer to a 33t pinion than a 23t.

Remember those gearing recommendations in the manual are for 2.0" wheels, NiCd and 4-minute races.

I believe the LRM trans is 2.18:1 ratio.

86/23 x 2.18 = 8.15 FDR
86/33 x 2.18 = 5.68 FDR

Will a pinion that big fit?

[RogueIV]

I run a 30t on mine when using the 21.5.

[Tucsonan]

Thanks guys. I was able to fit a 30T pinion easily. The JRX-Pro is now all wired up and ready to run. I haven't gotten it out to a park yet but it does some mean burnouts on my carpet with the orignal Losi tires

[Charlie don't surf]

I'm at 75/31 with a HW stock spec G2 and Reedy SP5 21.5 with 47* timing on blinky with a motor fan with my Jrx Pro- runs around 120* at 5 min on our silly putty type clay offroad track