Electrathon America Forum

Kalie_CHS · Member

Gearing For Specific Races

mhodgertt · EA President

I think your teacher has an excel spreadsheet I set up for the etek motor and the different speeds. What you do is find out what the race was won at last year and then using this chart gear about 2 to 3 miles faster if you think you can win or about that speed if you want to try for the top 10 but insure you don't run out of power. If you teacher does not have this spreadsheet, have him email me and I will forward the spreadsheet to him. It is set up so that different motor speed, drive tire diameter, wheel and motor sprockets can be put in and it will give the miles/hour you should be able to travel. I have it set up for all of the motor and wheel sprockets with the 20" wheels and eTek motors once they are down to about 22.56 volts (half way through race). I then have it posted on the wall for kids to look at so they can determine their gearing.
It is the same one I have in the back of my truck at races in case students want to change gearing at a race.

bd64 · Senior Member

Here is a not so old adage *** Gear too low and finish second. Gear too high and finish last. ***

Dave Cloud ???

Kalie_CHS · Member

I think I've seen that spreadsheet before. The trouble is, with our design, the drive wheel is only 16". We had to use a smaller wheel because of our frontwheel drive steering system. We are trying to create more space to move up to a 20" wheel, because we are having trouble to gear for the right speeds with such a small wheel.

radigan · Member

Measure the actual circumference of your rear tire with string and plug that measurement into the spread sheet. If you have not actually received the spreadsheet, let me know and I will email you a copy.

mhodgertt · EA President

The spreadsheet I have shared with many lets you put in the diameter of the wheel, and vary the teeth on either or both sprockets, as well as the motor RPM. When you do this on the computer the various speeds are calculated for you.

Nitoragro · Senior Member

This might be a little late but do you still have that spread sheet?

mhodgertt · EA President

Nitroagro or anyone else send me an email and request my sheet to let me know what you want and I will send it to you on excell.
Hodgert

Nitoragro · Senior Member

This is AWESOME! Thanks for the help

mhodgertt · EA President

Nitoragro. You are welcome! I like to help out anyone that I can to learn more and do better at races....even the teams we compete against. I invite any team to come to our shop take pictures, measurements, I'll give handouts and any knowledge, ideas that I have to help them out. I feel that the more others know and the better we do the better we are forced to do to compete and so everyone learns more and the races are more fun and meaningful. Several seasons ago we had about 12 of the top 15 cars in the NW and while it felt good it was not much fun. Since then others have improved (or we went down) and now it is much more even among the NW teams. We still have the most cars and so by odds we often have a number of top cars but the races are often won and even swept by other teams. BUT WATCH OUT THIS YEAR AS I FELL LIKE WE HAVE A GOOD TEAM AGAIN!!!!!