ESC Electric Recumbent Hybrid Bicycle
Electric Street Cuda
Or the ESC...
A project by Warren Beauchamp
While sitting inside on a cold and wet spring day, and thinking about a new version of electric assist recumbent bicycle, I drew this. It's still fully suspended and has the same seat height seat as my existing e-bike, but has the motor tucked under the seat, and the battery behind the seat. Also it's a bit shorter wheelbase, so it may actually fit a car bike carrier.
Later I realized, Hey, I already built this bike!

This is the Street Cuda. I built it 7 years ago, and I don't ride it much. Time for an update! Because I have been commuting to work on my original electric bike for a couple years now, and it is less than zippy, I am rebuilding this bike with a motor system which should provide a little zip.

Through Steve Delaire at Rotator I obtained a new motor/controller, which is an OEM'ed 500 watt Cyclone system .

The motor has two drive cogs, and is designed to be used like an "intermediate drive". It allows pedaling without driving the motor, motoring without driving the pedals, or both motor and pedal power. The drive cog is a standard 14T Shimano track cog. This makes it easy for me to swap it out for a less than standard 20T track cog for more speed.

Here's a mockup of the new motor on the street racer - looks good!

Matt pointed me to some bare LiPo cells at, but they would need a battery management system (BMS). There are good e-bike and battery discussion forums at

The Electric Street Cuda (ESC) is now being constructed.

Here, the motor bracket is fabricated and clamped to the frame The human portion of the drive train was tricky, and requires that I mount some intermediary gears up by the head tube to route the chain over the front wheel. In this photo they are held in place with a large clamp.

The ESC now has all the brackets brazed into place, and the chain installed. The chain line worked out pretty well, there is now clearance for the suspension fork.

The seat is now an inch or two higher, which should be fine as this will be a commuter and I will be riding with cars.

As seen here, the motor drives the bike through the standard bike gears. This means I will be able to gear down for the up hills, and gear up for the down hills.

The bike now weighs 42lbs. With battery it will weigh about 52lbs. No lightweight, but still 8 lbs lighter than the last electric bike.

I'm planning on putting the MOAT tailbox on this bike. I was not able to easily mount it to the other electric bike.

This past weekend I attached the battery and did some testing. The motor seems to work well. I ordered and received the 20T cog, but have not installed it yet. I may have to raise the seat again a bit to clear the bigger cog. The bike feels heavy now.

Mostly I just stared at the bike trying to figure out the best place to mount the battery pack. I finally decided that I'd mount it behind the seat as in the drawing at the top of this page. If I repackage it in a Coroplast box, and cover it it black duct tape, it should be well protected and compact enough to fit.

I spent most of Saturday working on the bike. I built a battery mount, added the larger 20T cog to the motor, raised the handlebars, and rebuilt the seat mount again to raise it a bit more. Today after dinking with the seat more and doing some inside testing, I took it for it's maiden voyage on my 5 mile system abuse test loop.

I'm not happy. The bike seems to max out at about 25MPH, with plenty of gearing left over. It seems happier at about 22MPH. It does some kind of strange cogging at low RPMs. Maybe some kind brushless motor thing? 

I also found that it's the battery's BMS that has been cutting out, not the controller, as this system does exactly the same thing as the other, only at a lower speed. 

Either my old 450 watt Currie motor actually puts out more than 450 watts and uses less current, or there is something wrong with the Cyclone motor. The motor was very hot after my 5 mile test ride. I was pushing it hard, but I push my old 450 watt motor hard too and it was never that hot.

I have removed the motor from the bike, and will be shipping it to Doc Pearson for him to use on his EZ3 trike. This is a perfect use for this motor. Eventually I'll have to remove the brackets and convert the old Street 'Cuda back to the way it was.

This did not work out so well because the system needed more power, but additionally, a bike to be ridden in traffic needs to be higher, so the next attempt will be with a higher power motor and a higher bike.

What's next? The ZCommuter project


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