1972 Honda CB350F conversion process

rfndzc

100 mW
Joined
Apr 14, 2020
Messages
49
Edit: Project complete. 6-8 weeks design, 3-4 months build out over quarantine summer 2020

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Hey all,
Sharing a progress pic on the Honda I picked up in January. Quarantine has been productive...
23s lifepo4, 72v 140A continuous (10kw) to an Israeli Revolt 160E outrunner, geared for torque.
A9B296C3-D8CA-42A0-ADFE-4C5160ED952F.JPG

Cheers,
Rob
 
Hi rf,
That's quite a creation and it looks like it will go, and stop with the disk brake.
I had a Red 1973 CB350 and remember it being 'twitchy' or frame 'flexy' seemingly from front down tube twist during bumpy turns.
Take care, you have more powerplant torque
Good Luck
Mike
 
Stealth_Chopper said:
Hi rf,
That's quite a creation and it looks like it will go, and stop with the disk brake.
I had a Red 1973 CB350 and remember it being 'twitchy' or frame 'flexy' seemingly from front down tube twist during bumpy turns.
Take care, you have more powerplant torque
Good Luck
Mike

Excited to even know what that is! Bike was not running when I picked it up, so have yet to ride... Thanks
 
A static test for your bike frame:
Straddle the bike, you must to have room to move it.
Shake the handlebars through hard short swings right and left to try and initiate a natural frequency vibration.
Or not, your "F" model maybe better than the '73 I had.
 
Got the bike on the road. Fairing needs some work yet but it rides excellent and the acceleration is unreal, beyond expectations. IMG_2316.jpeg
 
One of the best "street" (?) electric motorcycles I've seen.
Nice job
Does it have a license plate?
 
Stealth_Chopper said:
One of the best "street" (?) electric motorcycles I've seen.
Nice job
Does it have a license plate?

Thanks Stealth, much appreciated. Not shown in the pic but yes, I hung the plate. It is street legal and soon my commuter to work. I've estimated about 50 mi to the charge. Currently testing that.
 
Wow again, I mean it looks legal, but really !
I thought the lights were for 'show'

How do you feed them, with your 'powerplant' battery?
Or Maybe a compact convenient 12V
Mike
 
Yea, it all works, even the 4 indicators on the 'dash' though I've made the oil and neutral indicators reference the accessory position (red) and contractor closed (green), respectively. All the lights including the headlight were converted to led. I have a 4-wire isolated step down converter (72v to 12v) for lights and horn and whatever else I might need. The contactor is behind the 72 side cover on the left, and the converter is behind the cover on the right. Here's the finished bike:

CEFFD092-4776-434F-B051-E5AAAD4C40EA.jpeg
 
Nice ebike. How are you making 100% sure those battery poles can't make contact with the metal side covers? I would absolutely use plastic, wood, or composite side covers...anything except metal or carbon fiber (since it's electrically conductive too).
 
Definitely recommend a layer of FR4 between each cell. Otherwise - I love it! Totally rat rod. :bigthumb:
 
Thanks y'all. There is a layer of foam rubber (thin yoga mat) and another of 1/8" abs plastic separating the terminals from the steel fairing.
 
TorgueRPM said:
You mentioned 10kW continuous, what is the peak power?

The controller is rated for 340A peak, which works out to about 25kw
 
rfndzc said:
TorgueRPM said:
You mentioned 10kW continuous, what is the peak power?

The controller is rated for 340A peak, which works out to about 25kw

I found your thread on ElMoto, keep in mind that peak power can't be calculated from motor current, only battery current. So your peak power would be 72V * peak battery current
 
What controller are you using? The bike looks really great, I love it

Edit: 140 amp Kelly controller. I found your other thread on El Moto.

I too want to use 13 LiFePO4 cells to get 72 volt but I'm hoping I can get away with as low as 25 Ah capacity so that the battery pack is much smaller in dimension. I know this will reduce my range but will this also effect the take of speed? Or does that depend on the controller? I'm working with a 160cc Honda.
 
TorgueRPM said:
rfndzc said:
TorgueRPM said:
You mentioned 10kW continuous, what is the peak power?

The controller is rated for 340A peak, which works out to about 25kw

I found your thread on ElMoto, keep in mind that peak power can't be calculated from motor current, only battery current. So your peak power would be 72V * peak battery current

True, I don't really trust the cell manufacturer's peak Amp rating (3x 100A) and wouldn't feel comfortable pushing past 200A peak, but the busbars and the controller will do this happily. I probably haven't taken much past 10kW around town
 
mannydantyla said:
What controller are you using? The bike looks really great, I love it

Edit: 140 amp Kelly controller. I found your other thread on El Moto.

I too want to use 13 LiFePO4 cells to get 72 volt but I'm hoping I can get away with as low as 25 Ah capacity so that the battery pack is much smaller in dimension. I know this will reduce my range but will this also effect the take of speed? Or does that depend on the controller? I'm working with a 160cc Honda.

I think a lower Ah capacity might suffer the voltage drop on acceleration more than a higher capacity system, but it will also be a lighter motorcycle, so less weight to accelerate. Getting 23 cells into this bike (72v) required the thinnest profile I could find (width and height of the face). Once I had a sense of what that was, I looked for the longest battery that still had a narrow profile, so as to maximize Ah. In other words, I decided first on 72v, then 100Ah was the most capacity I could find in a cell that still fit the profile needed for 23 of them.

Yes, the kelly KLS7245H, 100/350A cont/peak
 
rfndzc said:
I think a lower Ah capacity might suffer the voltage drop on acceleration more than a higher capacity system, but it will also be a lighter motorcycle, so less weight to accelerate. Getting 23 cells into this bike (72v) required the thinnest profile I could find (width and height of the face). Once I had a sense of what that was, I looked for the longest battery that still had a narrow profile, so as to maximize Ah. In other words, I decided first on 72v, then 100Ah was the most capacity I could find in a cell that still fit the profile needed for 23 of them.

Yes, the kelly KLS7245H, 100/350A cont/peak

Thanks rfndzc. I learned a lot between asking you that question and now, and I ended up getting 40 used LG Chem li-ion pouch cells to build a 20s2p pack that should have around 20ah capacity and 60amps discharge rate
 
mannydantyla said:
rfndzc said:
I think a lower Ah capacity might suffer the voltage drop on acceleration more than a higher capacity system, but it will also be a lighter motorcycle, so less weight to accelerate. Getting 23 cells into this bike (72v) required the thinnest profile I could find (width and height of the face). Once I had a sense of what that was, I looked for the longest battery that still had a narrow profile, so as to maximize Ah. In other words, I decided first on 72v, then 100Ah was the most capacity I could find in a cell that still fit the profile needed for 23 of them.

Yes, the kelly KLS7245H, 100/350A cont/peak

Thanks rfndzc. I learned a lot between asking you that question and now, and I ended up getting 40 used LG Chem li-ion pouch cells to build a 20s2p pack that should have around 20ah capacity and 60amps discharge rate

Great, pouch cells have some very compelling characteristics for customized builds. If I ever do another ev project I would definitely consider them.

I watched your video, well done. I'm honored to be included, but please credit the community, 'rfndzc via endless-sphere.com' for ex. Good luck with the project.

Robert
 
I own the exact same bike, except 1974. I've been toying with the idea of converting it to electric since it's been very hard to get running in recent years. And like you, I really would love to use it as my commuter to and from work.

If you wouldn't mind, what did this whole build cost you, approximately? I'm trying to get a sense of what this is going to cost me and I think your setup is one worthy of emulating.

Thanks!
~ Jake
 
themrbruceguy said:
I own the exact same bike, except 1974. I've been toying with the idea of converting it to electric since it's been very hard to get running in recent years. And like you, I really would love to use it as my commuter to and from work.

If you wouldn't mind, what did this whole build cost you, approximately? I'm trying to get a sense of what this is going to cost me and I think your setup is one worthy of emulating.

Thanks!
~ Jake

Just seeing this... Batteries were about $1200 w/shipping (at the time). Motor and controller about $1500. All told about $5k on parts and materials. I did all the fabrication myself but for the aluminum motor mount plate which I had machined at a local shop (~$250).
 
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