Motor Sag Slow on Rear Direct Drive (Is it due to age?)

Hello all,

I'll get to the point. I have 2 e-bikes (both Cycle Analyst 3). One has a new front wheel motor (recumbent bacchetta) and the other is an older hard tail MTB with a rear motor (maybe 3+ years). Both are direct drive. I noticed that the older motor set to limit to 300 watts, I get 20 miles per watt and with the newer motor, with the same specs, I get 11 miles per watt. So the older one sags with that amount of wattage while the newer motor is pretty good. Average speed is 20 mph but older one is around 13 mph. Is this because the motor is old? Does it need to be replaced? There is no brake rub going on. Thanks for the advice!

Alex

Alex, I'm guessing you mean the bike with the older motor used 20 Watt Hours per Mile and the other bike used 11 Watt Hours per Mile. You also mentioned that the older motor was limited to 300 Watts, I guess via the CA-3. I don't know anything about the CA=3, but I would guess the lower speed is because of the Watt limit, Can't you increase the Watt limit and see if the bike goes faster?

I also suspect that the discrepancy in the Watt Hours per Mile is because one or both of your CA-3s isn't calibrated correctly. Again, someone with CA-3 knowledge will need to help you here.

These motors come in a lot of different speed versions. If your old one is a high speed version and you run it with low power and at low speed, it will run very inefficiently, which means higher battery consumption, less speed and less output power.

For starters, the bent is waaaaaaay more aero than the mtb. It sure better get lower wh/mi.

20 wh/mi is pretty normal for mtb's going about 18-20 mph, and bents getting well into the low teens is normal. 11 wh/mi is exceptional for the bent but not in heard of. It could be that the CA is also not quite perfectly calibrated, for some reason. Or, maybe you ride it a tad slower?

Check the CA's, for shunt value, and for wheel size. both bikes.

Great news everyone,

I have found the solution to my problem. Two things. 1st – My Cycle Analyst wasn’t calibrated to the infineon controller I received from EM3EV. Rassy and dogman dan were right. The Rshunt for the mountain bike was set at the default 1 and the controller’s resistance stated on the box was 2.11. 2nd – I had programed the infineon controller prior the Cycle Analyst install and limited a couple factors, such as speed, power, amps and was unaware that they were still in effect after the CA install. I have fixed these issues and have test ridden the bike. Works like a charm now. Thank you for your input and advice.

- Alex