Honda CB750F Bought

The search is over! And the winner is one really beautiful 1982 Honda CB750F Supersport.  She’s a one big lady from the 80’s, but the conversion should lighten it up considerably. My preliminary 3d sketches indicate that I should be able to fit my batteries real nice and tight inside. And since the bike is in such an excellent condition (even the tubular frame is sandblasted and painted), this will spare me a lot of time and I can concentrate on just the conversion. The engine compartment will receive some shiny black molded fiberglass fairing panels that I intend to design to fit the style of the bike.


On the component front, the battery charger and 12-tooth front sprocket for the electric motor arrived last week. The #50 sprocket should work fine with the 530-chain that the CB750F uses. Now I have pretty much everything I need to start rigging things together…


Next I’ll be setting up the test bench to test out all components and EV wiring setup. That should be interesting… The actual conversion I’ll begin only after I’ve had some time to get used to this motorcycle as gasoline powered. (Not before I have the driver’s licence.)

Also borrowed an XBOX kinect sensor from work that I intend to use for 3d scanning the bike into a 3d model that I can use as a reference when designing the engine compartment fairing panels and for planning the battery box design.


Main Components Have Arrived

Got two pretty big packages this thursday and friday. The first package including motor, controller, twist throttle and contactor arrived thursday, from the good old US of A. The package really didn’t take too long to arrive (thanks to DHL that handled everything just fine).

And here’s the pics of the motor and the controller. The motor especially is quite a beast. Should have plenty of power for my needs. And the controller is perfect match for the motor. Should also be a very robust device, and easy to program with USB connection to PC (the fun part).

ME-1003 Motor

Alltrax AXE 7245 Controller

The batteries also arrived friday, ordered separately from the Czech Republic. The cells felt smaller than I had imagined, even if I already knew their exact size. Interesting to see how I will arrange them inside the bike frame. Shouldn’t be a huge problem, considering these are pretty decent sized cells. They will be fitted inside the custom welded battery boxes, made to fit inside the frame and installed (hopefully) on the original motor mounts.


Today I also went to see this pretty nice Honda CB650C, but unfortunately I decided not to buy this one, as it’s front forks had been modified (into a lot longer ones) and this specimen, due to these modifications, had spent a bit too large chunk of the available percentage our laws allow to modify the bike, spending them into something I don’t intend to change that much. Considering that the conversion will eat quite a lot of the available percentage, I don’t want to waste any unnecessarily. (So no cigar today either, even if it was close.)

Next I might go and take a look at a bit more expensive, but much better shaped 1982 CB750 model. We’ll see…

Close, But No Cigar

The 1972 Honda CB500 I went to see last sunday seemed like a really nice bike and I liked it a lot. But for it’s price it would have needed quite a lot of work to get it in proper shape so that I can drive it for a while before the conversion. I’m hoping to find some nice bike in running condition first. Less to tinker with and I can concentrate my efforts to the actual conversion, when the time comes. I think the CB500 could have been the perfect sized bike, but there aren’t many in the market over here right now (this is such a small country). There are also couple 1980-1982 CB750’s in good shape that could be great frames for my project. Maybe I’ll go and take a look at those next. And there are other brands and models of course, but somehow I really like these Hondas. Good solid bikes with great reputation and should be easy to work with.

On another note, I’ve been following close by what Ted Dillard has been up to, as his little bike is very close to what I want to do with mine.  It happens that his motor and all the other components are pretty much the same I’m about to install into my motorcycle. Here’s a really nice video of him driving with his “R5eIII”, now with the same CALB cells I’ve already ordered for mine. If you’re interested making your own electric motorcycle, I can really suggest buying his “from Fossils to Flux” ebook.

Also stumbled onto another blog discussing the advantages of bottom balancing – my chosen method of keeping the battery cells in shape for years to come. I really suggest reading this, if you really think some BMS is the way to go.

Full Charge Ahead!

Now I’ve purchased all of the major components as I’ve ordered also the KP-E 600W 72V 6A charger, so I can charge the batteries. I was thinking of installing the charger inside the former gas tank, if I can make sure there’s enough air flow. The bottom of the gas tank will be gutted open so I can place the controller and charger inside. I hope they will fit. And this way it would be safe from the rain. I might replace it with a 1.5kW weather proof charger some day, if there’s enough room for it in the chassis (maybe under the seat where the 12V battery used to be?). That would be the ideal onboard charger. Silent and fast.

In my scooter I have this small cheap chinese 48V 6A charger that’s usually stored below the seat, but I have to place it on the leg platform when I’m charging, as the seat compartment would only heat up too much (no air flow). So my solution in rainy days has been to set a rain cover over my scooter. As the charger is placed on the leg platform, it’s also safe from rain, thanks to rain cover. Also the cover works as a pretty good child-deterrent, I’ve noticed. There’s a kindergarden just next to where I work, and there’s been some small dirty footprints all over my scooter when I haven’t covered it… Heh. Little buggers. (Yeah, I might sound like an old geezer, I know.)

Also I’ve received the email confirmations that my conversion kit (motor & controller etc.) and the batteries has been shipped. As they’re delivered by DHL and TNT, it shouldn’t take too long until I’ll receive them.

Next sunday I’m going to see one of my most likely bike candidates. It’s in Helsinki so it’s not too far from where I live. We’ll see how that turns out. It’s not in driving condition at the moment, as it has been sitting in storage for 3 years, but I’m very hopeful it could be the “perfect candidate”. We’ll try it with a fresh 12V battery and we’ll change the stale gasoline and see if we’ll get it running. (I would like to buy it in running condition.)

Also today is my last theory lesson in driving school. Then the next step is that I’ll get to ride an actual 600cc Honda CBF600N. Yay! (Scary.)

Batteries Ordered

se40aha_z1Okay. Now I’ve also ordered the batteries from, and also a 12-tooth front sprocket from for the electric motor. I ordered 25pcs of the 40Ah CALB SE40AHA cells, ie. the “blue” CALBs. I’m hoping that everything will have arrived way before I get to actual conversion phase. This way I can plan things with more precision and the project won’t get stalled because I’m missing something essential. And I can test everything on bench before installing all of the equipment into the motorcycle.

A Beginning of an Electric Motorcycle Conversion

A while ago I used to write this blog about electric mobility, mainly concentrating on my experiences with my electric scooter and other electric vehicles I’ve bumped into. Eventually there was so little to say anymore, that I decided to quit the whole thing (and deleted the blog). But this lovely little scooter of mine is still around and I’m currently using it for my commuting. Just over a month ago I got it from the storage and started driving it again. Ahhh, summer.

But to get to the point… I’m now about to sell my scooter, as I’m starting to convert a gasoline powered motorcycle into an electric motorcycle to replace my scooter. And this will certainly consume a lot of space in this blog. I’m hoping to do the actual motorcycle conversion during the following summer, after I’ve obtained the full motorcycle driving licence, as I’ve already started taking the safety classes at a local driving school (the scooter I’ve been able to drive with my car driver’s license). When done, in the future, I’ll continue customizing the bike to my own liking, maybe into some kind of electric cafe racer or bobber/chopper. It’s a pretty big project, but it should be fun.

I’ve already contacted two separate professionals. One that is going to manufacture (CNC) my motor mounting plate (the part that connects the electric motor into the frame of the bike) and the another one, a professional aluminum welder who is willing to manufacture my battery boxes to my specs. I will have 25pcs 40Ah CALB cells inside the battery boxes, bottom-balanced and charged to 87.6 Volts (72V nominal). The motor & controller kit that I’ve just ordered, includes motenergy ME-1003 electric motor combined with Alltrax AXE7245 (72 volts and 450 amp) controller, both of which have proven their worth in many garage conversion around the world. This should provide a decent package to become the power train of my daily commuter. The bike should have 40+km range and enough top speed to cover all the required speeds in our neighbourhood (up to 100km/h). I could easily aim for more range or speed, but that would require higher voltages, bigger battery pack and more expensive 96V controller.

So I want to keep it in budget – and at the same time fill all my personal transportation needs. And this package should be more than good enough for me, while being a lot cheaper (about 1.5k€ for the bike plus up to 4k€ conversion) than the cheapest Brammo Enertia (8850€), which apparently is discontinued in any case and replaced by the way more expensive Enertia Plus (13880€). I actually considered the cheaper Brammo, but it’s still way too expensive in my opinion. (And my own conversion will be way more cool. Not to mention easier to maintain and upgrade as needed.)

The bike frame itself is still undecided, but I’ve already contacted one guy selling his 1972 bike. We’ll see how that turns out… In any case it will be a 1970’s or early 1980’s naked 500-750cc street bike (most likely Honda, Kawasaki, Yamaha or Suzuki). The former engine compartment will be filled with the electric motor and battery boxes. To “make it pretty”, I’m planning on fabricating some sort of shaped fairings (like these) to cover the angular battery boxes. I want it to look like it’s a sleek design from the past, not a “frankenbike” from the Mad Max movies. I was actually thinking of modelling the fairings in Softimage XSI and having them 3d printed by Shapeways (which I’ve got plenty of experience in my RC related projects). If printed light and thin, I could reinforce them with fiberglass cloth and epoxy resin very easily. No need for molds or plugs. And I could leave the printed models inside the fiberglass cover. Same for cafe racer seat pan. I only have to see how much it would actually cost to print them and how I could spare some of the printing costs by design. But going 3d printed would be cool enough to justify the bit higher costs.