JRX PRO SE GEARING

[brian s]

what gearing should i use running a 10.5 brushless in the jrx pro. also what is the internal ratio of the gearbox.

[bearrickster]

10.5 is way over kill on a Jrx series of car. I have run a stock brushed and 17.5 and ran side by side with 10.5's they dont need the extra power on most tracks. its just harder on the componets. just my 2cents

[brian s]

this is the only wind motor that is more or less suitable for the losi that i have at the moment, all my others are 8.5 or less.
it`s only going to be run for a few rounds in our vintage series along with my rc10 and optima, so don`t really want to buy another motor i possibly wont use.

[bearrickster]

It will take it, I had one in my LX-T and ran it all year with no problem. its just over kill. I ran the red lx-t spur I think its a 86T and 18T pinion with a Retrofit trans

[Brandon G]

I ran a 81-24 in my B4 with a 10.5. B4 ratio is 2.6:1. Final drive ratio: 8.775:1
(81/24) X 2.6= 8.775

If you run the LRM tranny, you are looking at 2.18:1 ratio, so to get a similar ratio of what I ran in the B4, your spur divided by pinion needs to equal approx. 4.03.

Example: if you run a 81 tooth spur on the LRM, you will need to run a 20 tooth pinion. 81/4.03=20

Of course this is all speculative. Final tuning may still be needed depending on how free your drivetrain is and how the motor temps after a full race pace run. If you have a means, run a slipper on the buggy. Don't let the diff slip or it will eat the diff gear quickly. A 10.5 in the LRM will make this car fly.