1971 Honda CL175 conversion

[StultusEst]

Here are some pictures of a Honda CL175 I converted over the past year. I learned a whole lot doing this conversion, mostly due to my philosophy of "measure once cut thrice" leading to many "learning experiences." I would not have been able to complete this project without the guidance of many others more intellegenter than I, and tools and space at my local makerspace.

Right now I'm working on a luggage rack to replace the slightly sketchy milkcrate.

The cable management has since improved...slightly.

This video helped me tremendously with figuring out the wiring for the bike:

Having access to a laser cutter made prototyping a lot easier.


Additional context to explain poor design decisions: This was built by a highschooler without a complete grasp of his own mortality.

I'm happy to answer most questions. I relied heavily on endless sphere during this build so it seems right to share my experiences.

 

[harrisonpatm]

Hey, great job for your first build! Tell us your battery, motor, and controller specs when you get around to it, and what performance you're seeing.

 

[StultusEst]

Hey, great job for your first build! Tell us your battery, motor, and controller specs when you get around to it, and what performance you're seeing.

I got the battery through Amorge, its 72v, 120a continuous, 80ah. It can do 60-80ish miles depending on the speed and weather. I'm very happy with the range, but if I had more of a budget I would have liked more continuous amps.

The motor is a qs273 8kw hub motor, it came in a kit with a Sabvoton 72150. From what I've learned this controller is a little underpowered for the application. Being able to program the controller through my phone is nice.

With flux weakening the fastest I've gone is 63mph (down a hill with a passenger).

I haven't ridden many motorcycles outside of the MSC so I don't really have a great frame of reference for how it handles and accelerates compared to a gas motorcycle (which is probably a good thing). I've heard this controller limits acceleration off the line to prevent wheelies, which matches what I've experienced.

 

[harrisonpatm]

I haven't ridden many motorcycles outside of the MSC so I don't really have a great frame of reference for how it handles and accelerates compared to a gas motorcycle (which is probably a good thing).

That was my frame of reference too, I've never ridden any kind of motorcycle ever until I built an electric one. It's a fun experience! I recommend taking a local motorcycle skills course, it helped me a lot. And your likely to get some good input on your build

 

[Dui ni shuo de dui]

The motor is a qs273 8kw hub motor, it came in a kit with a Sabvoton 72150. From what I've learned this controller is a little underpowered for the application.

Indeed, the 72150 is a great controller, actually one of my favorites, but your motor could take a lot more.
That being said, it is a spoked 8KW motor. From my experience the spoked motors can't take as much abuse as the ones with the solid rim, the thermal dissipation is a lot lower. In my opinion it should max out at around 20KW, give or take.

The battery continuous draw doesn't matter too much in our application, what really matters is the peak draw. You rarely stay with the throttle maxxed out for hours, usually it only lasts a few seconds before the next red light or the next turn.
Most low quality cells are capable of doing a 3C discharge safely, so with a 80Ah battery you should expect a maximum discharge of around 240A. That is, if your BMS can accomodate for it.
In which case you could fit a more powerful controller and get better acceleration, possibly a higher top speed as well.

Nice build and thanks a lot for sharing it with us!

 

[StultusEst]

I finally upgraded from a milk crate. I welded up and powder coated a rack out of square tubing. I bolted on an ammo box which has the benefits of being waterproof and lockable. it is smaller than the milk crate though.
i need more bumper sticker ideas.

 

[dominik h]

I The motor is a qs273 8kw hub motor, it came in a kit with a Sabvoton 72150. From what I've learned this controller is a little underpowered for the application. Being able to program the controller through my phone is nice.

With flux weakening the fastest I've gone is 63mph (down a hill with a passenger).

Be careful with flux weakening. I killed two Sabvoton controllers.
I played with the flux weakening on the main stand. The Sabvoton controller does turn of flux weakening when you close the throttle and then gets damaged from the voltage generated by the up to 50% higher spinnning motor.
If you want to accelerate faster from a standstill, you can change to a Fardriver ND72680. Smaller in size and nearly twice the phase amps. But if your BMS can only handle 120A , then you will only benefit on the first meters from start.

 

[StultusEst]

Be careful with flux weakening. I killed two Sabvoton controllers.
I played with the flux weakening on the main stand. The Sabvoton controller does turn of flux weakening when you close the throttle and then gets damaged from the voltage generated by the up to 50% higher spinnning motor.
If you want to accelerate faster from a standstill, you can change to a Fardriver ND72680. Smaller in size and nearly twice the phase amps. But if your BMS can only handle 120A , then you will only benefit on the first meters from start.

Thanks for the tip! I think I saw your post about the dangers of flux weakening under no load before because otherwise I would have definitely killed my controller.

I believe my BMS can handle 300 amps peak. I know I'm able to manually raise the continuous amps limit on the BMS, and the cells should be able to withstand more, but I'm not sure about how many amps the BMS can take. Does anyone have experience with the ANT BMSs?