Speedmunkey

Your manual should tell you that ratio. A Losi XXX-T MFE for example, has a 2.43:1 and an Associated T4 has a 2.60:1..

What it is, is the amount of gear reduction that takes place internally. Using the Losi for example, every 2.43 (I) turns of the spur gear makes the wheels turn 1 complete revolution. So, for every 40,000 (R) revolutions of the motor, if using a 20 tooth pinion and 86 tooth spur (X = 4.35:1), you get 3784.1 tire revolutions...

(R/X)/I = 3784.1

Now, to expand upon this, if you take the circumference of your tires, let's say you have a 3" tire which would have a circumference of 9.424" (C), and multiply that by the resultant from the above formula which we will name (F), you'll find that you travel 35661.4" per minute, theoretically anyway.

C*F = D

Then, you multiply your distance per minute (D) by 60 to give you a distance per hour (H) in inches, divide by 12 to convert inches to feet, and then divide by 5280 (M) to get your theoretical miles per hour.

(((D*H)/12)/5280) = M

So, if you work through all of these simple equations, you'll arrive at the final answer of 33.8mph... I think I might have to make another spreadsheet for this one too. I personally think top speed calculations are pointless, but most people disagree. Feel free to critique my math guys, it's far to early for me to be thinking this clearly, so i'm probably wrong lol

EDIT: Btw, I think I just duplicated Skrap's speed calculation, but with a bit more clarity on the equations used.