lc_60 said:
I'm making an e-bike and bought last year an e-bike kit from BMSBATTERY with a Bafang BPM 48v 500W sensored hub rear drive with 201 rpm for a 26" and a KU123 controller, and I also bought a 48v 10ah Ping battery for it. As I use to cross step hills as i travel from home to work, this year I thougt to buy a front kit with the same characteristics to make a dual drive e-bike with independent throttle, (in fact i only use the PAS and the 3 switch speed). The day before yesterday I bought it from BMSBATTERY and yesterday they e-mail me sayind that they only have sensorless hub motors to deliver. Now I don't know if I can syncronize these motors being one sensored and the other sensorless, because I think the sensorless one could have a rough start power than the sensored and they wil be pulling and pushing each other.
The question is, can I use the sensored one wihout connect the 5 wires to the hall sensors and make it sensorless too?
Well, you left a lot of stuff out like, what bike and do you like to pedal, being the most important.
But here goes.
Just get the 36V/350W frt. The wind will be a little different, which is not a bad thing. You don't want to run any more than 1200 Watts or so on the frt., so get the KU93. More power than that and they get kind of difficult to control when WOT. It will spin a lot and will spit you on your ear when you least expect it.
These are geared motors, they freewheel so there's no "pushing", but they help each other by "pulling" each other up into a slightly higher efficiency range.
If one runs the exact same systems on one throttle, they can "sync-up" electrically, which I found unpleasent.
When you get tired of the crude PAS, thinK about dual throttles, I do mine this way;
Half twist[left side]/stk. BMS Battery thumb right next to it.
Easy and intuitive to use.
You can drive 80 to 90% of the time on just the frt., as it will be smoother and use less battery power. It will be a higher wind, but should be nice for cruising in the 25 to 30 mph range.
Both motors together will climb like as homesick angel.
But like the others have said, you need more battery. A lot more battery.
You should read my build thread.
It's about mini's, but I think most of what I found to apply, will apply to the BPMs as well.
You will have to deal with good torque arms, which I, for the most part, didn't.
There was a recent post here about BPM speeds, where a reader really nailed down their no-load rpm values. you need to find it and plug in some ajusted values in the Ebike CA Simulator. Use the BMC and BPM. motors provided and note that you can overlay both motors on the same graph.
Another way to search those BPM posts is to use Google, Put in Bafang BPM, BPM, etc. and go for the Endless Spere threads that slow up.
