Just wanted to share the brushless top speed and gearing calculator I've been using..
 

Just wanted to share this with you guys. For a while I've been looking for a gearing calculator that includes a little more than just the final drive ratio. With this calculator you can enter a brushless motor's KV rating, max amperage, and the your trans, axle, and pinion/spur, to get your total max speed, torque, and current draw. It's been pretty useful in calculating what I need for a motor in my next build.

Here it is-

R/C Calculations

Re: Just wanted to share the brushless top speed and gearing calculator I've been usi
 

Here are a few of the ratios I've been playing with. Some aren't usable for my project, other than the fact that I can compare them to what I'm looking for.

Losi Axle Ratio-12:1
Losi Trans Ratio-2.5:1

Redcat Micro Axles-1.85:1
Redcat Micro Trans-Garbage

Micro SCT Axles-2.53:1

Micro T-2.6:1(?)

Re: Just wanted to share the brushless top speed and gearing calculator I've been usi
 

This is most likely going to be my new setup for my micro basher/hillclimber/jumper/rock-jumper project. Remember, the 18.24MPH top speed stated is FLAT OUT! I should see usable speeds of around 15MPH. I'm looking for something that'll keep up with a stock Micro SCT, but will go places they won't dream of.

This all started with my sick sick fascination with seeing big tires, lots of power, and a set of locked straight axles tearing stuff up and jumping everything in sight!

Differential Ratio: 1.85
Transmission Ratio: 2.5
Other Ratio: 1
Spur Tooth Count: 55
Pinion Tooth Count: 15
Total Voltage: 8.4
Motor KV: 4500
Tire Diameter (inches): 2.25
Tire Ballooning (inches): .25
Motor Current Draw: 6
Motor Coil Resistance: 0
Spur/Pinion Ratio: 3.67 : 1
Total Ratio: 16.95833 : 1
Tire Circumference (inches): 8.64 inches (219.44 mm)
Rollout: 0.51:1
Total Motor Speed: 37800 RPM
Vehicle Speed: 18.24 mph (29.29 km/h)
Effective KV Value: 4500
KT constant: 0.3 oz-in/A
Motor Torque: 0.01 ft-lbs
Final Torque: 0.16 ft-lbs
Final Power: 50.4 watts (0.1 HP)

These are right from the calculator, showing the difference in single pinion teeth. There's a HUGE range of speeds available while still running the same 55T spur.

Pinion Speed
10T 12.16 mph
11T 13.37 mph
12T 14.59 mph
13T 15.80 mph
14T 17.02 mph
15T 18.24 mph
16T 19.45 mph
17T 20.67 mph
18T 21.88 mph
19T 23.10 mph
20T 24.31 mph