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Hi Nate,

I'm very interested in your project! I've been considering similar projects for some time but haven't had time to get very far in the planning process, let alone start building. Congrats on getting as far as you have!

Are you familiar with the Endless Sphere Forum? There are more bicycle EV oriented people there. Also, your design goals seem similar to the BugE. Look into it if you haven't already.

Here are a couple of my thoughts after reading this thread.

Weight should be roughly equal on each wheel for best balance. Putting too much weight on the rear will probably make your trike tip easily.

If you're worried about spokes, how about solid BMX wheels? I don't really know much about them other than that they exist, but they might handle lateral forces better. Might be worth looking into. I don't know anything about hub strength. Jory Squibb's Moonbeam used 2 scooter front assemblies.

As far as your rear configuration goes, I think Hempy has a point. Your design is a bit much, but if you want to over engineer, maybe look into mounting a motorcycle swingarm. That should give you suspension and chain tensioners.

Finally, is your trike legal for where you live? Here in California, if an electric trike is capable of your desired 35 MPH, it would need to be registered as a motorcycle. "Motorized bicycles" can max out at 30 MPH if they have the right equipment. Most states limit them to 20 MPH. As a motorcycle, you'd likely need DOT tires among other things.

Can't wait to see how this turns out! Keep us posted. Good luck!

Thanks for the interest and kind words, John. I have not seen Endless Sphere, but I have recently come across the BugE and was also surprised at the level of similarity. As for the front wheels, I am taking most of the weight off them, so I am no longer all that worried about strength. Most of my worries therein were regarding the one sided hubs, but I will be, when I have some free time, install some homemade bicycle forks to replace the single-sided connections, which should eliminate this issue. This design update will put most of the weight on the back wheel, but I had not considered tipping as a possiblity until you brought it up, mainly because almost all of the weight is centered below the axle line.

I will be registering this as a Specially Constructed Vehicle, which is a designation California uses for vehicles like this or hot rods. The registration process is very easy, and mostly just consists of some paperwork, a light and brake test, and a CHP inspection. I don't think the non-DOT approved front tires will be an issue.

A word of advice: make sure this is what you really want to build. It is difficult to straddle strength, weight, comfort, and budget. A heavier and less efficient or lighter and less powerful vehicle would be much easier to build.

Good luck with whatever you decide to do, and I will be excited to see your results!

Oh, you ARE in California. I'm very interested in hearing how your registration process goes. I've researched California SPCN for motorcycles, but it'll be great to hear about someone going through the process with a homebuilt EV trike.

If you're in Southern California, you might want to check out the Alt Car Expo in Santa Monica on September 30 or October 1. I've been two or three times. I sat in a BugE and saw Jory Squibb's Moonbeam and a Corbin Sparrow among other interesting vehicles. It seems to be moving away from DIY toward corporate, but there's usually some pretty cool stuff going on, and admission is free.
http://altcarexpo.com/

Personally, I would avoid putting so much weight on the rear. I'd worry about tipping while swerving to avoid something. Check out how easily this Messerschmitt reverse trike tips!
http://www.youtube.com/watch?v=InlFaERcPeA

You should look at some Electrathon America cars. I used to build/race them in high school. Back before the safety rules caught up we had cars with sub-100lb rolling chassis. About 180lbs ready to race, plus the minimum-weight driver at 180lbs. The goal was to go the furthest in 1hr. I set a few record speeds, 61mph at an oval, 36mph around a park, 72mph on a road course, never did win a race though.

We ran two 12V wheelchair batteries, weighing 64lbs.
Lynch 8", cryotreated
The controller was a 400A for a golf cart, I think, also cryo'd
Mountain bike hubs/HD SS spokes, 20" BMX rim
Hayes 6" hydraulic brakes, front only

We designed and built everything in house, they were nuts
Custom steel spindles
Aluminum chassis, no suspension
-1" round roll bar
-2" square front axle
-1"x2" lower frame rails & rear 'swingarm'
-1" square upper frame rails and diagonals

We made a lighter chassis too, but the driver and ballast became structural. The lower frame rails were switched to 2"x2" angle, and the upper frame rails and diagonals were made of 1" strap. It also made the car narrower and shorter, saving like 1sq ft of frontal area. Real fast, but scary.

http://www.electrathonamerica.org/Welco ... erica.html

Not my school, not my cars. My pics haven't met the digital age yet. Just an example. Ours were mostly open cockpit for simplicity, with only our helmets above the body it didn't seem necessary.