what pinion for a d4 & 8x2 motor?

[bryn]

as a still newbie. what size pinion should i be going for? my d4 seems slower than my old bosscat on the same motor and pinion? i'musing i think an 80 tooth spur.

cheers,
bryn

[Adam Skelding]

Hi Bryn,
I've never run brushed in my D4, so I can't give you an exact answer.
I'd start off at an overall ratio of about 10.0:1,maybe even 10.5:1.

It's best to be a little undergeared first and gradually build up pace until you find the motors limits.

[bryn]

thanks adam, how do i calculate the ratio though? spur size/ pinion?

cheers,
bryn

[Adam Skelding]

Hi Bryn,
The Overall ratio guide is in the manual.

Basically.

(Spur/Pinion) x 2.4375 = Overall Ratio.

e.g.

(80/19) x 2.4375 = 10.26
(80/18) x 2.4375 = 10.83

These 2 ratios shouldn't be far off. Depends on the make of motor though. You batts will make a difference too.

[bryn]

bloody hell!!! too many variables thanks adam. greatstuff.
bryn

[Bullet69]

The gearing chart in the rear of the manual suggests an 18T pinion for a 10T