My new wheel and motor wasn't ready yesterday after all, so I've whiled away an hour doing some comparisons between various hub motors that are available.
The results were quite interesting. There seems to be a popular belief that the various 400 series Crystalite motors trade torque for speed, but this doesn't seem to be quite so clear cut. The other results were pretty much as expected. The figures below are for a motor in a 26" wheel, with a 36V, 8Ah, NiMH battery, with a 35A controller at full throttle. I decided to compare torque at minimum realistic speed (5mph) and also the speed (in mph) at which the motor power reaches zero.
I don't have figures for the TongXin/Nano, as the motor curves don't show the low speed characteristics, but extrapolating from the graph it looks to be similar to the eZee.
For comparison, as far as I can tell, a really fit person can deliver about 80 to 100 N-m average torque at the bottom bracket, perhaps 40 to 50 N-m at the rear wheel with a 2:1 gear ratio, more with a really low granny gear.
Jeremy
The results were quite interesting. There seems to be a popular belief that the various 400 series Crystalite motors trade torque for speed, but this doesn't seem to be quite so clear cut. The other results were pretty much as expected. The figures below are for a motor in a 26" wheel, with a 36V, 8Ah, NiMH battery, with a 35A controller at full throttle. I decided to compare torque at minimum realistic speed (5mph) and also the speed (in mph) at which the motor power reaches zero.
I don't have figures for the TongXin/Nano, as the motor curves don't show the low speed characteristics, but extrapolating from the graph it looks to be similar to the eZee.
For comparison, as far as I can tell, a really fit person can deliver about 80 to 100 N-m average torque at the bottom bracket, perhaps 40 to 50 N-m at the rear wheel with a 2:1 gear ratio, more with a really low granny gear.
Jeremy
Attachments
Last edited:
