Classis Vespa Smallframe to EV

Great build, I started a electric vespa (P200) project many moons ago unfortunately was unable to finish. But would be great to start on another project 58 VBB.

Tony
Bakersfield.
 
Eddy: I finally tid a fit test today. It went in *almost smoothly. The motor mount bushings out of the original engine were a little too big and I had to grind them down by about 1mm in dia. Also the shock mount is a little farther forward than stock so it’s riding about an inch taller. I’ll post some photos.

SlowCo: Yes, machined from a single block of 7075 Al.

Skaiwerd: they did thread the holes - and they’re perfect. I got quotes from 8 different vendors, and those holes doubled the price on a few on them. I used 3DHubs and had an excellent experience.

Yankee1919: it’s been a fun process so far - you should definitely give it another go!

Tomorrow should be the first time actually driving the thing. I did a bench test of the system with an ignition key and throttle, and was able to switch it on and crank it up. The motor is making an interesting noise on acceleration, sort of like a fast clicking, but who knows what that means. I only have a small 20s1p test battery built, so I’ll be limited to around 1500W, but it should actually move!

I’ll post again the test. In the meantime, i’ll try and add a few fit photos.
 
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One thing I love about this swingarm design is that you can just barely see the little Brembo caliper sticking up on the left side. The axle nuts make it very easy to get the disc positioned correctly before clamping down. Not sure how well the clamping action will work - torquing down on the bolts only seemed to open and close the gap by about 0.5mm, but again, it's a work in progress.
 
Funny, though... Just as I get this project off the ground I discovered the world of single shaft motors.

The swingarm has been a great project and I'm super stoked to keep working on it. However, I think if I was going to put a kit together I'd probably leave off the disc brake (upgrade the front to a disc and just run regen on the rear), and I'd develop a way to attach a single shaft motor to the original engine case. Almost every vintage vespa already has a functioning swingarm in it, and I think there's a way to use that. Especially because the drum brakes are basically where you'd want the motor to be.

I still have the little 125 that came out of this thing. I was going to try and save everything in case I wanted to put it all back together, but let's be real... So I think as soon as I get this one finished I'm going to tear the old engine apart and see what it takes to add something like this to it:

http://www.qs-motor.com/product/10inch-4000w-single-shaft-in-wheel-hub-motor50h/

What I'd really love, though, is to find low profile tires that would let me use one of these 13" models with a removable rim:

http://www.qs-motor.com/product/13inch-3000w-single-shaft-e-max-hub-motor-with-removable-rim/


They have clean lines, cost about $350, max out at around 11 hp and 150 ftlb, and would make changing tires SO easy. I just don't know if there's a way to get them to fit.

Next time :)
 
Guys it works!!!!

I’m only running a 20s1P battery (the one I made to bench test) but I stuffed everything into the chassis and rode her up a hill!!!

More torque than I was expecting from the little battery pack, and I’m being very careful not to push it too far (it did heat up a little). But man it’s satisfying to twist the throttle and go. Much more power than the little motor that came out of it :).
 
I have motors with 13" rims and the lowest profile tire I've ever been able to source ends up a 19.25" OD, which I don't think there's any way to fit where a 10" wheel was. It's not just the diameter, but the width too, since the lower profile 13's end up 5"+ in width.

If you get any more of those beautiful swing arms done for motors with 13" wheels, count me in for a few.
 
Hey Aaron, so cool to see that you've test driven the scooter!
What are your plans for battery and controller locations? will you be able to fit it all beneath the seat?
 
She works! After a major repositioning of components, mainly moving the controller to where the old engine was, my wife and I took the little thing for a test drive. She works great!

The biggest issue now is with the throttle. In the crash the grip throttle gained some friction, and it’s too much for the return spring to overcome, which means the throttle stays where you put it. Kinda scary. I also have it programmed for a delay which is really weird. I thought it would make it smoother, but it turns out it just makes it harder to trust what you actually selected.

I’ll try and throw some photos up.

Next things to work on:
  • Throttle return

    Headlight and horn

    Rear brake (disc and caliper already installed, and I have a cable pull master cylinder that should bolt in)

    Rework the battery - I think I have the BMS installed incorrectly, and I want to increase it from a 20s4p to a 20s5p. I have the space...

    Turn signals... have to see if they mess up the cuteness, and I’d need a different plan for the kill switch.

Anyway I’ll try and post some photos (I think there’s a size limit stopping me from sending them from my phone).
 
Here's a few of the photos.

This is the controller going in. Nicely tucked into the engine compartment, attached to a leftover piece of plexi that I'll use to make a more substantial replacement.
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Here she is outside with the same cover off.
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This is the rest of the electrics. The 20s4p battery drops in, and I had an inkling of adding a fan before I realized that I can current limit through the controller. I'm going to take the fan out and make this a 20s5p to give it a bit more range.
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And finally here she is all buttoned up. Well sort of. You can see all the wires hanging out from the switch cluster (I took them all out and used one of the switches as a main power switch.
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Even on the test drive down the block my wife and I got a few compliments on how they'd never seen an electric scooter like that :).
 
No idea on top speed - the motor says it's good for 110kph which sounds reasonable. I was able to get this thing to climb smoothly 50 before my "this is a prototype" sense kicked in. It still pulled really well at that level. I've also got it limited to 28% of battery current to keep the draw on my pack at under 100A. I've heard that voltage is more important at top speed, but either way it seems to be doing just fine.

As for weight I don't know, but it seems lighter than with the gas engine, with a low center of gravity. In a pinch I think I could pick up the whole thing - definitely not a problem lifting the back end up if I need to move it around.

And for the weight, the only thing I have to go off of is other bikes with similar power output / battery size. The Stealth Fighter bikes have a similar weight and from what I can tell have 1.4kwh batteries that give them 75-100 miles of range. My battery is 0.9kwh so at the same efficiency I'd be looking at 45-60 miles. My efficiency won't be the same, but if I could get 40 miles out of a charge that would be great.
 
Hi,
These cheap brakes and extension work great on my honda elite conversion.
https://www.amazon.com/Areyourshop-190cm-Fitting-Stainless-Swivel/dp/B01N7GM0F5
https://www.amazon.com/BRAKE-MASTER-CYLINDER-CALIPER-ASSEMBLY/dp/B00EGSHBOA

They wont be dissipating a lot of heat but are essential.

I learned that a simple ebike throttle was much better than trying to retain the original for the same reason.

The swingarm is gorgeous but consider using welded steel for a prototype. My scooter neeeded ...refinement. even if you dont weld, the cost would be lower if you cut the steel and fit it. Who knows, you might even start welding.

Best
 
Wow, that swingarm is absolutely insane. To be honest I don't really like the way it looks once installed on the bike (too beefy for my taste), but it is definitely incredible and very well made. Totally awesome.

As for your battery, if I understand correctly 900Wh/72V=12.Ah, this is really on the low side, I don't think you'll get much mileage unless you're riding at really, really low speeds. I'd say don't expect more than 15-20 miles with your current battery (that's vastly speed dependent though).
Regarding top speed, since you use a 72V battery and a Kelly controller which doesn't have flux weakening, I guess you should reach around 70-75km/h, provided your battery will be able to deliver that power (which, given its rather low capacity is not guaranteed).

If possible, try to add more capacity, the frame is relatively big so I'm pretty sure you could fit around 25Ah-30Ah without much trouble. That will help you to get more range and also to get much more power from your controller without being too harsh on the battery pack.

That being said, kudos on the build, it's very clean.
 
One place you can add battery is a backpack. I have 3/5 of my 1.7 kWh pack in my backpack. It rides on the seat under way. Its good for handling, making you a big guy on a smaller scooter. You take your pack when you park and nobody can drive it away. You keep those classic lines. I can charge in a safer place.
 
I’m interested in the CAD files for the swingarm, if those are shareable or possible to track down in any way. Very appreciative of the info that has been shared in this thread about the swingarm fabrication. I am looking to convert my 1960 VBA 150 in a similar fashion, and from the photos posted, it seems the general layout of the swingarm elements might work for my scooter. I’m expecting I’d still have to tweak the dimensions a bit, but I’d prefer to not start the whole process entirely from scratch. I’d appreciate any suggestions from the group!
 
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