I wanted to post some gear ratio and torque/force I calculated for the Brammo Empulse R.
Motor Peak Torque: 90N-m (66.38ft-lbs)
Rear tire: 180-55 ZR17 0.32m (1.033ft) radius
Transmission Gear Ratios:Primary: 35T/59T = 1.69:1
1st: 14T/30T = 2.14:1
2nd:16T/28T = 1.75:1
3rd: 20T/29T = 1.45:1
4th: 22T/27T = 1.23:1
5th: 24T/25T = 1.04:1
6th: 20T/19T = 0.95:1
Final Drive: 14/38 = 2.71:1
Torque at rear axle:
1st: 882.09 N-m or 650.60 ft-lbs
2nd:721.33 N-m or 532.03 ft-lbs
3rd: 597.68 N-m or 440.83 ft-lbs
4th: 507.00 N-m or 373.94 ft-lbs
5th: 428.68 N-m or 316.18 ft-lbs
6th: 391.58 N-m or 288.81 ft-lbs
As a fun little exercise, I wondered how much force is that on the road from the rear tire? I did this wrong the first time by using ftlbs and newton-meters interchangably, thanks to Protomech for questioning me, I was rushing
We know Torque = radius * force * sin(90). We have torque, so the equation becomes Force = torque* 1/r
The angle is 90 degrees since the road is tangential to the tire, so its just 1. So one newton-meter of rotational force would equal one newton of force at 1 meter away. My "rear tire ratio" is 1/r, or 3.13. If calculating using feet, the ratio is 0.97.
Rear Tire ratio: meters: 3.13:1 (feet 0.97:1)
Rear tire peak force at rubber:1st: 2760 N or 620.47 lbf
2nd: 2258 N or 507.62 lbf
3rd: 1871 N or 420.62 lbf
4th: 1587 N or 356.77 lbf
5th: 1342 N or 301.69 lbf
6th: 1226 N or 275.62 lbf
Here's some tools to convert from N-m to ft-lbs and from Newtons to lbf (pound force):
http://www.unitconversion.org/energy/newton-meters-to-foot-pounds-conversion.htmland
http://www.unitconversion.org/force/newtons-to-pound-forces-conversion.html[edited: added lbf and ft-lbs calculations as well as corrected my rear tire ratio]
