Gearing for stock classes

[defcone]

Hello there, I just got a x4 pro and wanted to run 17.5t non boosted class. However I couldn't get the gearing right with the 85t spur, are there any other spurs which fit? Currently need a 5.5-6 fdr according to the guys that run.

[4_cell_racer]

Originally Posted by defcone

Hello there, I just got a x4 pro and wanted to run 17.5t non boosted class. However I couldn't get the gearing right with the 85t spur, are there any other spurs which fit? Currently need a 5.5-6 fdr according to the guys that run.

Looking at a gear chart

Your gonna need a 40t pinion to gain a 5.52 fdr or a 36t for a fdr of 5.97

The spur for the x4 seems the same style as the Mad Rat/Mad Monkey which are 80t so you could go 38t to gain a fdr of 5.47 or 34t for 6.12 fdr

Search for Mad Rat Spur (JE Spares) and there should be a pic of the MR/MM spur

Hope that helps?

[defcone]

Originally Posted by 4_cell_racer

Looking at a gear chart

Your gonna need a 40t pinion to gain a 5.52 fdr or a 36t for a fdr of 5.97

The spur for the x4 seems the same style as the Mad Rat/Mad Monkey which are 80t so you could go 38t to gain a fdr of 5.47 or 34t for 6.12 fdr

Search for Mad Rat Spur (JE Spares) and there should be a pic of the MR/MM spur

Hope that helps?

The problem is that it looks like the biggest pinion I could get in there is a 25-28t. And it doesn't look like a 80t will be small enough? Is the internal ratio 2.437?

Thanks for the help.

[damselfly]

If that car uses the same layshaft as a Mad Rat you can use t4 spurs which are available in 78t. I think a 75t is also available.
Losi Kevlar Spurs also fit.
Again, if the transmission is the same as the Rat it's a 2.6:1 ratio.
When I had a 80t spur fitted to my MR the largest pinion I could fit was a 30t unless I slightly modified the motor plate.
This gave me an fdr of about 7:1

[defcone]

Originally Posted by damselfly

If that car uses the same layshaft as a Mad Rat you can use t4 spurs which are available in 78t. I think a 75t is also available.
Losi Kevlar Spurs also fit.
Again, if the transmission is the same as the Rat it's a 2.6:1 ratio.
When I had a 80t spur fitted to my MR the largest pinion I could fit was a 30t unless I slightly modified the motor plate.
This gave me an fdr of about 7:1

But my car is the x4 not the mad rat, the 4wd Ansmann car.

[4_cell_racer]

Sounds like you might struggle getting the fdr required for that type of motor without moding the motor mount/a spur from another buggy!