Electric Catrike 700

Electric Catrike 700

A project by Matt Shumaker
This is my 2009 Catrike 700-E (electric). This trike was built as a means of testing how light and efficient an electric trike could be made. It was originally purchased new, then ridden for 100 miles or so to get the feel of the trike. After that, the electric system was devised and installed. Here is what I went through;

The CT 700 is a fantastically efficient trike. It is a joy to ride. However, because of its light weight, there are a few minor issues I needed to correct to make it capable of handling the added 25 pounds of electric drive and the added speed and power. First off I fabricated rear frame braces. These stiffened the rear of the frame, reducing flex in that area. Second, I replaced the flimsy (sorry Big Cat) rear 700 wheel with a much more sturdy 26 inch, 36 spoke rear wheel. This, not only, provided a stronger wheel with less flex, it also gave me the opportunity of running a slightly fatter rear tire. The tire OD is only 1/4 inch smaller than the 700 wheel. So, the stance of the trike is unaffected.

Photo by Matt Shumaker

Photo by Matt Shumaker


 Lastly, that wheel swap was needed for the disc brake flange. That flange allows mounting of the electric drive sprocket to the left side of the wheel. This gives a completely separate system for pedal and electric drives. They are completely separate drives. If one fails, the other is totally independent and still operable. Also, the motor system freewheels. This allows pedaling without any motor drag.

The lithium polymer batteries are mounted in black anodized boxed under the seat, along with the controller. These were machined in our shop. The battery boxes, and controller box, are VERY rigidly mounted to the frame using my production drive unit frame mounts.
 
The drive unit itself is my production RC motor reduction unit with an elongated jackshaft and bearing tube. This moved the motor and belt drive primary out of the way of the pedal chain. I am, also, running a torque limiting slipper clutch on the drive. This allows for hard throttling without belt skip, or over torquing of the drive system (these motors have HUGE torque!). The motor is an Astro Flight 3220 (94% efficient) and a Castle Creations HV160 controller with a custom throttle interface.
Photo by Matt Shumaker

Photo by Matt Shumaker

Photo by Matt Shumaker
This trike sees a very low 14wh per mile at 20mph! It is the most efficient trike I have yet seen. All up weight as shown is a touch over 59 pounds with all batteries on-board. The trike is good for 30 miles on a charge without any pedaling at all. Top speed is 30mph with a full charge. It has the power for much more speed. But, this gearing is optimized for maximum range.
 

Photo by Matt Shumaker

Photo by Matt Shumaker
Lastly, as a finishing touch, I made adjustable tillers. I am not a big fan of traditional vertical tillers. So, these provide a much more comfortable (for me) hand position. They also allow for easier operation of the twist throttle for the electric drive.

If you have any questions on this trike, or my drive systems, feel free to contact me at shumaker@owc.net

This trike, as with nearly all of my builds, is for sale. The price, complete with charger, is $7,000 plus shipping.

Matt

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