Gear reduction

I have a 144 volt system without a transmission. The transmission was replaced with my own gearbox reducer and works great up until I stop on a small hill at a stop sign and then try to pull out into traffic. There had better not be anyone coming. Otherwise, like I mentioned I really like the cog gear reducer I built. I have even built a second one and am having close to the same issues. Vehicle one weighs in at about 4,000 pounds and vehicle two weighs in at about 3,200 pounds and has a 120 volt system. The cost difference between purchasing or building an adapter plate was about three times that of what my engineered gearbox cost complete.

The 144 volt system gearing is around 6.00:1 w/an advance 9" DC motor
The 120 volt system gearing is around 5.60:1 w/an advance 9" DC motor

Any help will be much appreciated.


I have been looking at the possibility of eliminating the need to shift in a conversion. With an AC drive you can get 11,000 RPM, 140 ft-lb torque and 105 HP using 350 volt pack. I was looking at using a powerglide 2 speed transmission (about $100 on ebay) and rip out the high and reverse gear and lock it into low 1.82:1. Couple this with a 4.45:1 rear end and away I go.

Since I am really only interested in the gear-reduction feature of the powerglide, can you tell me more about your gear-reducer? Weight? Possible gear ratios? Cost? Energy consumption/absorption of the device?

I like simple and inexpensive, that is why I am looking at the powerglide.

Thanks for your input.


I would think you would need at least two gears. The DC motor doesn’t have the RPM range you need to get good results at one ratio. for starting 8:1 or 10:1 would be better than 5.6:1, but a 10:1 will severly limit your top speed. AN AC motor can have a RPM range of 10,000 or more, most Dc motors have a range of 3,000 - 4,000.