What size gearing would you recommend.

Hi, I am planing to go with a Tekin 1700kv motor/combo on 5s in a Truggy.
The Spur gear is a 50T.

The clutch bell that it was running with nitro was a 13T.

The question is what would size would you recommend for a pinion gear for this motor battery setup for racing.

Should i stay with a 13T or go up a few sizes or down?
Any information is greatly appreciated.
Cheers.

[suicideneil]

Based on a tyre diameter of 5.65" ( average-ish 1/8 size, bowties in this case ) and normal truggy diff ratio of 43/10, then 50/13 = 32mph. I'd say step it up a bit really and go with 44/13 ( = 36mph ) maybe, depends how large or tight your track is.

http://www.scriptasylum.com/rc_speed/_top_speed.html

Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 44
Pinion Tooth Count: 13
Total Voltage: 18.5
Motor KV: 1700
Tire Diameter (inches): 5.65
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 3.38 : 1
Total Ratio: 14.55385 : 1
Tire Circumference (inches): 17.75 inches (450.85 mm)
Rollout: 1.22:1
Total Motor Speed: 31450 RPM
Vehicle Speed: 36.32 mph (58.35 km/h)
Effective KV Value: 1700

Thanks for the reply.
So doing a few more calculations
50T spur and 15T pinion = roughly 36.5 mph.

Excellent.
15T depending on how tight the track is.

Appreciated.
Cheers.