Electric Bicycle Trailer

Very nice write-up from Ken about the Electric Burley Coho Trailer he put together using our 52V electric bike kit.  Many of our customers over the years have installed our kit on trailers, but Ken provides the most detail about the process and outcome.  Realize that there are a number of variables to consider when building an electric bike trailer, so give us a call to discuss.

“Hello Doug, I’m very appreciative of all of the help that I had from you.  I knew NOTHING about electric bikes when I decided to make the e-trailer, and you prevented me from making any consequential or expensive blunders…Here is a Facebook post I did about it, share if you want:

I made an electric bicycle trailer for Kathea.  I’ve since made some improvements to the trailer.  I’ve put the battery down into the bottom of the deck to lower the center of gravity to improve the stability.  I’ve also wrapped the dual hitch balls with electrical tape to decrease the free play in the hitch, which was excessive.  That helps the stability.  I’ve lowered the tire pressure to smooth out the ride, and improve the traction.
I plan to get a much softer spring for the trailer suspension.  This is designed for a 70 pound load, and Kathea will normally not have much more than a battery in the trailer.  I will still have a mount for the battery on the fender, as seen here, so that we can put the battery in the high position for more cargo when the trailer needs to be fully loaded.
The power to the trailer comes from a pedal assist mechanism at the bicycle crankset (I chose to leave the throttle off that comes with the system).  A ring of spinning magnets sends impulses to the controller which activates the motor.  It takes a spin of the crank and then the motor takes off.  Power stops immediately when the pedaling stops.  There are five levels of power assist.  The first level gives excellent support to the rider.  The second is much more powerful.  I’m not even sure what the fifth level of assist is for.  It might be like pouring nitro glycerin into the gas tank of your car!  We don’t know yet what kind of mileage Kathea will get from a charge.  It depends upon how hard one pedals, and what level of assist one uses.  For another $500 we could carry a second battery and double the range.  That will depend upon Kathea’s ambitions.
Better traction can be maintained by having less disparity between the rider generated torque and the motor generated torque:  In other words, pedal harder and don’t use as much pedal assist on steep climbs—or carry some cargo to increase trailer tire traction.
Advantages include versatility and utility.  The trailer can be adapted to multiple bicycles so that several people of widely differing size could use it.  It can carry cargo.  It’s fast.  It’s less costly than a good electric bicycle.  Electric bicycles that are near to the same price aren’t as good.  There are a few commercially made bicycle trailers available.  I couldn’t find anything that had all of the features that I was interested in, so I made this.”  
Ken, Bow WA
Click link for a video of the Electric Burley Coho Trailer performance.