LRP 3 star gearing?
 

Anyone know what sort of pinion should be with for the old style LRP 3 star brushless motor with stock spur?

20-22 was the range i used last year

I dont know what the stock associated spur is (82?), but isnt it

Spur / pinion * internal drive = drive ratio

82 / 20 = 4.1 * 2.43 (xxx-cr it the only one I know) = 9.963 (or 9.9:1)

According to the LRP website manual for x11 (yes I know it's the older motor, but still around 55k rpm), drive ratio for the 5.5t is around 13.0:1 or 14.0:1. On the Losi, that makes a pinion of around 14/15

Youd have to substitute the associated spur and internal drive ratio obviously

Found on LRP site ratio should be 11.0:1 so that makes pinion 19.

i am quite sure mine is the three star motor, and i am running 21 tooth pinion with stock spur gear on an original lrp sphere with reedy motor combo. Baz Weldon used to run his on a 19 pinion and always thermalled it.


that was on a b4 too.

wouldnt a bigger gear (higher ratio) be the cause of thermal due to over gearing?

Nosram 3* on 18/19 with 78 spur indoors @ TRCC with X6 (uses a B4 gearbox internals)

Last year I used a 4 star for a couple of meetings and ran a 17 or 16 pinion, so 19 sounds about right to start off with for 3 star. Will just see how it goes on track.

maybe, but mine (on the 21 pinion) doesn't thermal, the LRP with the 19 pinion thermalled. Draw your own conclusions :eh?:

the gearing i am using came from a suggestion by Doughty on his website, so who am I to say it's wrong?

not saying its wrong , just curious as maybe we go the wrong way with gearing wen we have a thermal!

Maybe its just down to Lead thumb Weldon ;):D

I was advised to try gearing up a tooth when i first got my lrp brushless by a couple of the helger drivers.

My 'ASSUMED' reasoning being that you were not making the motor have to rev as high to achieve a speed, the higher the rpm the faster the esc has to switch after all, and as i understand it is the switching that causes the heat build up in the esc. The higher load in the system of higher gearing is less damaging i again assume.

I left a 21T pinion on mine all of last season rain or shine without any problems.