Homebuilt Power Assist and other Bike Trailers

Power assist trailer version 1

This power assist trailer had multiple dc output voltages,
110 vac and was also a source
of compressed air.

This trailer has it's own page showing the original setup.
Just click HERE or on the picture.

Power assist trailer version 2

This trailer used a 2.5 hp engine I bought from Harbor Freight turning a 24v alternator. It did work but could not put out enough amperage to effectively run the trike without stalling the motor all the time.

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Power assist trailer version 3

This is the latest version that is now in use. I took the 6.5 hp engine off the other big trailer and the 24v alternator off the smaller one.

This setup works very well.

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Dump Truck Trailer

This trailer was built to move some dirt around in the yard. The funny part was my wife got some kids to shovel the dirt for her before I got done building the trailer. Oh well......

It was built on the frame of the big power assist trailer since I rarely used it. It's not fancy but it gets the job done and I can pull it around with my mobility scooter in the yard.

Power pusher electric assist trailer Version 1

Side view

Hitch detail

Front view

This trailer was built for a friend of mine that kept commenting that he would like to have power assist on his bike. There was a slight problem though is he has a full suspension mountain type bike so the only motor setup I could think of that would be really available to him was to get a rear wheel with a built in motor.

Unfortunately he can't afford the prices that are asked for those so I decided I would try a different direction. I had a few motors around the shop and an old rear section of a scooter. I built the scooter section into a one wheel trailer that has a 36v 750w motor on it. The basket was pieced together from a few bits of wire shelving.

The tow bar that connects to the front of the trailer was made from the rear triangle of an old 26" bike.
It pivots side to side at the front of the trailer and up and down where it mounts to the towing bikes rear axle with a couple of small plates that have nuts welded to them. The front of the towbar also has 1/2" nuts welded to them and 1/2" bolts connect the bar to the bolts on the smal plates with about 1/8" space between them. This allows the tow bar to swing up and down.

I used car trailer light cables to connect the motor controller on the trailer to the throttle control on the bike so it can be disconnected easily when the trailer is not in use.

It has more than enough power to push the bike at a good speed (15-18mph) and carry stuff like groceries in the trailer. He has been happy with it.

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                                                          Grocery Trailer

View showing hitch

Rear View

Larger View
Hitch close-up


This one uses bed frame angle iron as the base material and 1/2" electrical conduit as the rails.
All the rails were brazed together top and bottom. The hitch triangle and forks were welded on. The bottom is 1/2" plywood that has been painted with fiberglass resin on both sides and bolted and glued down with more resin to the bed rail frame. Actually all the bed rail parts, brazes and welds on the frame was painted with the resin first before being painted blue. - an extra rust preventative measure.

  The thing is painted blue instead of green to match the trike because that is what color paint I had on hand and needed the trailer done quickly.

The forks that hold the scooter wheels are from 20" bikes and were cut down to fit and then pieces were brazed on at the bottoms where the axles are mounted. The pictures don't show it but the forks are actually welded/brazed for about 3" on that side where it is connected to the trailer. There is another piece of bed rail that goes across the middle on the bottom and is also welded to the frame and the forks. The forks are very solidly mounted with no give at all.

  1/4" plastic rope was used to net the sides and help keep the weight down some. That type of rope does not like to be tied in that manner either and so I ended up using some wire ties on the top, middle, and bottom rows to keep everything in place.

It has held quite a bit of weight so far in use. It will easily hold an entire full size grocery cart quantity of food.
                                                          Click any pic for a larger view