RcTek : Information & Resources for the Model Car Racer

RCGears - R/C Car Gear Ratio Calculator

As part of the software we have discovered through the internet, we found this great little Microsoft Windows program on our travels and really can’t fault it. We have seen many similar programs and whilst they were good, none of them were free.

What the RCGears Program Does

The RCGears program will automatically calculate the Gear Ratios, the Rollout and the Speed for any radio controlled model car, irrespective of whether it runs on nitro (gas) or electric.

The RCGears Screenshot

The RCGears Program Screen

How to Use the RCGears Program

The program couldn’t be any easier to use. The author, Stephen Waits, has predefined some gearbox ratios for you, but you can also define your own (see Customising the Program below).

You then need to put in what spur and pinion gears you will be using, as well as the tyre diameter and the RPM (revolutions per minute) of the engine/motor.

The program can be set to use Metric (mm) or Imperial (inches) by simply clicking on the Units button.

Installing & Running the RCGears Program

The RCGears program is supplied as a compressed zip file of 225kb. When you have downloaded the rcgears111.zip file simply extract the files into a directory of your choice using WinZip (or any other unzip utility). There are three files in the archive and these are;

rcgears.exe - the program executable

rcgears.dat - a data file that can be edited

readme.txt - contains info about the program

To run it, simply double-click on “rcgears.exe”. You may make a shortcut to the rcgears.exe program file if you like. See your Windows documentation for details.

Customising the RCGears Program

If you would like to add your cars gearbox/final drive ratio to the drop-down box, simply edit the “rcgears.dat” file using the Notepad program that comes with Windows (or any other text editor) and add a line for each new car you’d like in the list.

For instance, if you had an HPI RS4, it has a final drive of 2.1, so you would add a line like this:

HPI RS4 Pro 2;2.1

Save the file and then restart the program for your changes to take effect.

Technical Support

The RCGears program is supplied as is, with no guarantees. We have tested it extensively and have found absolutely no problems whatsoever.

Since the author has very little time to spare and the program is entirely free, he cannot support the RCGears program in any capacity. This means, you should NOT email him with any questions about how to use the program or questions about gearing. If you do send him messages with questions about how to use the RCGears program, he probably won’t reply. The same holds true of us.

As you can see from the screenshot above, the program is very easy to use and you should not need any help at all. The only problem I can foresee people having is by not editing the rcgears.dat file with a plain text editor and introducing invisible characters into the file that word processors use for formatting. If this occurs, simply extract another copy of the rcgears.dat file from the zip archive and replace the damaged one.

Please Note: that you will lose any customisations you have made to the file.

Download the RCGears Program

RCGears Download - 225kb

Download of the RCGears program. (225kb file size).

MD5 checksum for the zip file: ce75659f720eca7c21f1b33b26b40c83.

Scanned for viruses and unwanted programs, 28th November 2008.


This is a relatively old program, but potentially as useful as it ever was, especially with the advent of the low-powered ultra-compact devices;

  1. It seems to run OK on Windows XP, not tested on Vista. It has a good chance of running under other operating systems via emulation.

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© 2001, 2009 by Darren Burnhill