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  1. harrys

    My battery range: is it normal?

    You're probably burning 30 wh/mile running a 1000W motor at 20-25 mph. Your calculated rate is 720 wh/15 or 50 wh/mile. You have to derate that 720 wh. It based on a low current draw and using all of the battery. The latter can't happen because I believe the controller shuts off your battery at...
  2. harrys

    Layers of security

    What's the usual torque spec if you have a wrench? I've been using 35 nm (26 ft-lbs) and I still have at least one torque plate on the axles. Some axles on my motors are too short for double torque arms.
  3. harrys

    Invisible battery / hub project - what would be your recommendations for this use?

    The Q128H available from has a flange diameter around 140mm. It gets its name from the 128nn spacing between opposite spoke holes. Also available from, as the Akeima 128. While the extra cost for a rim/spokes is low, the added shipping charges are high, I bought a...
  4. harrys

    Ordered kt 36/48v 17amp controller, how/do i set up lcd3 for 36/48v

    I also swap 36V and 48V batteries into KT controllers. Thanks for mentioning the L1 parameter. Some of my ebikes have the older LCD's without L1. Their autodetect works well enough. Sometimes, when going from 48 to 36. the bar display is stuck low, but that often happens when I power up after a...
  5. harrys

    Yosepower 350w 36v rear hub with 36v battery

    I recently bought a used Bafang BPM front motor and decided to use a Brainpower 10A controller on 36V to keep the power down, as it was front drive. Wow, was it gutless. I switched in a KT 10A square wave controller that had 20A peak, and the kick when applying throttle was back. So you...
  6. harrys

    Torque spec ; 12x10 axles

    I've always done it by feel with a 17mm or 18 mm wrench about 10 inch long. The other day I found my 3/8" clicker torque wrench, so I decided to torque the nuts on a 500W Bafang in a steel fork. What's a good number for a 500W motor? I'm using 40nm here. Seems kind of high. My other bikes...
  7. harrys

    Brainpower 866C-6 controller

    Wouldn't be much of a password if everyone bike used the same one. Name the bike/model, start a new thread, and maybe someone with the same gear knows the answer.
  8. harrys

    Adding a motor to a Fabric Folding bike

    I don't know about weight. A motor weighs the same as it does on a storebought ebike as the converted ebike. However, I agree it's impossible to hide a battery like Fiido and Qualisports do with their seatpost batteries. As far as cost, I have to pay the markup on the motor and the donor...
  9. harrys

    General Advice for Bike Choice When Doing a Conversion

    I own a front motor, one bafang mid motor and a few rear motor conversions. It's important to get the wheel weight down so that they are easier to accelerate. I once bought a very inexpensive $79USD fat tire bike. Everything was steel, including the rims. I could barely pedal that bike 1.5...
  10. harrys

    XF07 on 20" wheel

    The buck converter will keep the voltage up as the battery drops, I was running it on a relatively big load for me, a fat bike motor. with a 20A controller. With a real time volt meter, I recall a 4V sag with throttle. It would probably would be less sag with my Q100 motors, but I'm already...
  11. harrys

    XF07 on 20" wheel

    I've used the buck converter. Yes, you could set it to 48V, if you wished, which will still be within the range of a 50V electrolytic capacitors in the 36V KT controller. The output is limited, I recall to 20A, but you will pull more than that out of the battery. What's nice is that I could...
  12. harrys

    Julet connector and wiring bundle

    It's a shame to cut your IT4 cable, but if you try to buy cable extensions and splice them to make your 5pin to 9pin cable, it will cost more than a new IT4. So it's knife, solder, and heat shrink. The wire colors will probably track all the way thru, but just to insure yourself if they don't...
  13. harrys

    Does anyone run a bbs02 on a 52 v battery ?

    My BBS02 is from 2016. Runs fine on either a 13S or 14S battery. Also can use pedal assist and feather in any amount throttle as needed. What I've read is that some time in 2018, Bafang changed the firmware so that the throttle behavior is mucked up. One cannot mix them together as precisely...
  14. harrys

    Advice on choosing the right kit, please.

    Where to place the controller, and attaching the pedal sensor are often the two parts of a hub conversion that take the most thinking. Never been able to use the ring mount as intended, screwed under a cap. Not going to use glue, so I end up fabbing a DIY mount for the sensor. I've tried the...
  15. harrys

    Still no response to my emails from BMS

    I had a problem with PSWpower sending a package to the wrong address 1000 miles away. They asked me to go there and get it. After DHL shipping sent me proof that it went to wrong address, Alice offered me a dollar. She must have been convinced I was a scammer. She thought she had the right...
  16. harrys

    Still no response to my emails from BMS

    Close the dispute and I suspect they go dark again. I thought BMSbattery would be better than that. I've bought four motors from them, but my last one, a AKM100, was from SHipping seems more reasonable.
  17. harrys

    A mystery rear motor with 36V controller and 48V battery

    If the controller is getting hot, it shouldn't be in a bag. Zip tie it to the frame, if you can. The open air will keep it cooler. If you can clamp it to the frame with a bracket, then you'll get the benefit of more heat transfer.
  18. harrys

    Ebike wire managment tips?

    Agree on the spiral wrap. I would get a few lengths in my kits and I set it aside, preferring to use automotive plastic wires looms, which are like spiral wrap but quite bulky. One day, I saw a cheap imported ebike. They spiral wrapped the whole front handlebar down to two groups, and it looked...
  19. harrys

    Voilamart hub motor not driving

    Last year, I deliberately miswired my 22A KT controller to spin a geared motor backwards. It was interesting to hear it whine with nothing happening outside. According to the popular bootleg schematic of the KT's, their microcontroller does have a learn lead, but it's tied off. If so...
  20. harrys

    Brainpower 866C-6 controller

    Simply put. learn mode is flakey. It almost seemed like the connectors were intermittent. Power up and nothing happens. AFter a few tries, it always spins backward. Then I break the connection, make it again, and it spins forward, but so slow, like 1-2 rpm. Sometimes, if I let it spin, it will...