Canadian
Unlocked Diamondback Powerline
Calgary, AB
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160
Published: 2024-06-15
Having been an "acoustic cyclist" commuter and road biker for many years, and having been a previous owner of a Specialized Turbo Vado, several Radpower bikes and a handful of Grin conversions, I really wanted to experience a mid-drive e-bike that was similar in experience to a road or commuter bike, but wasn't nerfed by canadian e-bike laws (like my enormously expensive Turbo Vado was). I love the flexibility and power that Grin conversions have given me, but I was too afraid to try modify my Turbo Vado, so I ended up selling it and sticking with geared hub motors (which have served me well!)
Then I found this bike on Kijiji and thought it might perfectly suit my needs. I purchased this Diamondback Powerline from someone that had it stolen then recovered by the police, the paint was badly damaged, the wheels had been swapped from a set of 27.5" 10 speed to a set of 700c with a 9 speed cassette so it wouldn't shift properly, the brakes and speedometer didn't work, and the power electronics wouldn't consistently provide power there was even a check engine light flashing on the badly scratched OEM ebike display. I didn't spend too much money so I felt comfortable with trying to modify it without risking too much, and I also felt pretty good about keeping this bike out of the landfill.
This bike has a Shengyi mid-drive CMT01N motor in it, and I have replaced the majority of the power electronics with Grin parts, including a Baserunner L10 and a Cycle Analyst, and I really love this thing.
I removed the motor from the frame, cracked it open, installed an NTC thermistor on the motor stator, then wired up an L1019 cable to the existing hall sensors and phase wires. I also supplied 5V DC to the torque sensor and measured the output voltage of the other pins to figure out the torque sensing and cadence of the pedals, I then hooked up these wires a standard Grin torque sensor cable and added an inline 10V to 5V DC converter board to make sure it would be compatible with the Cycle Analyst. I didn't have a speedometer, so I bought a cheap one off Ali Express and wired that up into the Cycle Analyst. I also added a super nice headlight (SPL-01 1900 Lumen Ebike Light) from Grin which is amazing at night. I built a 48V battery with a Hailong case, shoved the Baserunner L10 in there, then wired up the Baserunner and Cycle Analyst and configured everything and I was good to go!
Everything went fine on first ride, but I wanted to go faster, and the supplied chainring is proprietary, so I thought I was out of luck, but then I realized I could remove the chainring guide and put an additional chainring on (like you'd see in a 2x front DR system), so I slapped on a 50T and I was good to go! I completed the build in the winter, so I didn't really have a chance to test this bike out very much, but I was able to hit 50kph at about 1200 watts in the highest gearing. I was pretty satisfied.
Since spring has arrived in Calgary this has been my primary mode of transportation, at least when I'm by myself, and I've put several hundred kilometers on it. I've set the thermal rollback to start at 60C and stop at 90C and it seems to be running great under these conditions. I usually run between 2.0 and 5.0x torque with pedal assist and I find it to be super smooth, powerful and quiet. I can fly up hills with grades about 10-15 degrees at about 25 kph no problem and the motor only starts throttling if the hill is really long. I have been riding fast, and with a high cadence (70-90 rpm) yet I've averaged 9.2 wh/km, which I think is amazing given the aggressive speed and hill climbing I've been doing.
The motor is small, and rated at 250 watts, but I have noticed that the motor will handle 500 watts on a flat surface for a long period of time without overheating. It only really becomes a problem when the power levels climb to over 750 watts which typically means steep hills. I really think that 750-1000 watts is reasonable on an ebike, especially with steep hills and carrying large loads. If we got rid of power requirements in the laws and stuck with the 32kph limit I think e-bikes would be much more useful to many people out there, thanks Grin for helping me unlock the true capabilities of this bike!
Things that I had a tough time with during this build
* Routing the cabling through the frame. I originally tried making the L1019 modular with MT60s and JSTs inside the motor, but that was a bad idea. It is now just a hard wired L1019, which totally makes sense, the L1019 is modular anyway!
* Unable to auto-tune the motor. I got around this by loading up an Shengyi SX profile and modifying it to get it to work. Hall sensors seem to work fine, so I'm not sure what I did wrong.
* I have a throttle, but when I go throttle only it often has a hall sensor error and shuts off power. I'm going to be removing the throttle since this bike is best with pedal assist anyway.
* I can't find 27.5" rims with 100/135 QR skewers for a reasonable price anywhere. I'd really like to have this bike running 27.5x2.25 or thereabouts for a bit more contact to the ground for dirt/gravel trails. I might have to build my own in the winter.
Thanks for reading.
Additional Info
https://youtu.be/FBrKbwlE9aI?si=cJ0w3fWzFGbsB3mj