View Full Version : Gearing Confusions

07-19-2004, 08:13 PM
Ok... I'm sooo confused about gearing right now. A little background first. I have a Tamiya TT-01 and I'm just using the stock gearing right now (19t Pinion, 61t spur). Now, apparently that's geared well for Stock motors (or crap motors) where the motor is not torquey but you want to get all of the top speed out of it.

Now I've put in a 11x2 mod motor, and I find it's very very over geared with the stock gearing (it got so hot after two laps I gave myself a nasty little burn). Now I've called around to all the hobby shops in the area, and apparently what I want to do is drop a few teeth off the pinion. Only problem is because of the motor mount system the TT-01 uses, the smallest pinion I can use is the 19t. Now they said I could achieve the same by increasing my spur size, well go figure, 61t is the largest spur I can put on this chassis.

So being royally stumped, I give Tamiya USA a call, and the rep tells me to get a 55t and 58t spur, and then use the the pionions ranging from 20t to 25t, claiming that that would lower the temperature of my motor. Now here's what I'm wondering. The ratio of 19/61 is 3.21 turns of the motor to every one turn on the output shaft. Now lets take a look at say 25t/55t. That's 2.2 turns of the motor to every one turn on the shaft. Now since it's less turns to turn the wheel, wouldn't that mean I'm putting more stress on the motor?

I asked the rep and he said because it's a smaller spur, there is less resistance, thus it is less stress, but I don't quite understand how that works. I always figured, more turns of the motor to make one output turn means less stress. So why would this case with the 25t/55t work out oppositely?

07-19-2004, 08:55 PM
DaLurker I have to agree with you there man and don't understand what he's thinking. He's having you go with a LARGER pinion combined with a SMALLER spur, thus effectively gearing your Tamiya to the moon???

I know this is probably not the case, but it's like he's TRYING to blow your motor up. :D With an 11T mod, gear higher? I hope someone tells us what we are missing here, that is crazy.

One of the things I learned about Tamiya early on is their gearing is (in most cases) stricktly proprietary and you generally don't have a lot to choose from for the reasons you mentioned. It may very well be you might have to motor your RC based on the available gearing instead of the other way around.