Gearing for a Losi 7.5T brushless on a B4
 

Can someone advise on the above. I assume it'll be like a 12 x brushed motor

23 pinion to start? standard spur?

Does it give any recommendations for overall ratio in the manual? If so it can be worked out by:

Spur/pinion ration = external ratio
External Ratio x Gearbox ration = overall ratio...

e.g. 81/23 = 3.52
3.52 x 2.6:1 = 9.12 (overall ratio!)

HTH
Mark

Drop onto the Associated website and view/download the build manual... suggested ratios are near the back of the manual... :thumbsup:

Ive started off with a 18tooth with the standard spur and see how it goes. The manuals always seem to have really high gearing. better to let her rev than getting hot.

westw00d

Interesting thought, I might dig out a 19/20 pinion and see how it goes. Got to wire it in tonight and then replace the radio gear tomorrow with a 2.4Ghz Helios :)

I'm on 24/87 in the X-6 (same thing) and am thinking of going up to 25.

Brushless get too hot if under-geared also ;)

G

I'll be ordering up some new spur gears so I've got a selection from RW Racing and then get the right ratio.

Really did'nt know that!? will try a slightly bigger pinion even tho a 6.5 in my b4 is a little quick allready :drool:

gearing
 

vecta 7.5, 20/83. awsome.

Well I installed it last night and the car flips on it's roof and grip rolls.. Mmm wound out the slipper and now working on a new set-up for titchfields astro turf track. Boy this thing is quick and I was running NIMHs, not my LIPO. May wind it back a bit on the Helios.

All motors, no matter if they are brushed or brushless will get hot if you are under or over geared. My old V2's used to pull about 56000RPM, think how much more it would spin if you undergeared it. :cry:

I always run 24t on a 81t spur for a 7.5 and currently 22t on a 81t for a 6.5 and there both spot on for me :)

i ran an x-12 7.5t, on 25/81 today and it was really quick and was only using 900mah per heat :thumbsup: and didn't get hot.

do you mean 24/78 G?

run 7.5 sintered nosram on 81 26was well quick

Last sunday I ran my novak 7.5L on 25 / 81 (Nosram speedo and Lipo 3800 35C).
After a 5 minutes run, the speedo was almost cold and the motor was not too hot :thumbsup:

Yes :blush: But thinking of going 25/78 now.

G

Well I geared my 7.5 x11 81/24 and it ran very well, maybe a bit too quick.. Will see what happens this weekend at the track