I wanted to know if my ratios calc's are right

[howielong]

Well i decided to do this finnally. Im looking for a combo with a lot of torque. Some friend said the higher the ratio is more torque. Lower the ratio more speed. Well i did some math and found my ratios with my different spurs. So which one of the following will give me more torque for me.

72 Tooth spur
23 Pinion
2.625 tranny

equals to a ratio of 8.22

72 Tooth spur
23 Pinion
2.625 tranny

equals to a ratio of 8.90

72 Tooth spur
23 Pinion
2.625 tranny

equals to a ratio of 9.58

[tnxfan]

http://www.radiocontrolzone.com/cars/calculator.asp :cool:

[howielong]

I don't know how to use that thing. Seems confusing to me.

[gene465]

Actually it is easy once you get the hang of it. I wound up with a drive ratio of 8.21 using the 72S/23T/2.625 tranny ratio. Read the article that goes with the link it explains how to use it. I am terrible with math so I use this all the time now. Hope this helps. Gene

[rcguy2477]

For the calculations, all you do is divide the spur gear by the pinion (72/23) then multiply it by the cars raton(2.625). Its actually quite easy to understand. The first step is finding how many times the pinion must turn in order to turn the spur gear around once. The internal gear ratio is the number of times the spur must turn to make the tires turn once. you multiply the first step by the gear ratio because you are finding out how many times the pinion revolves to turn the wheel once.