Utility Cycling Technology: Motorized Bicycle Trailers

electrically activated disc brakes

How else can you put very strong brakes on a trailer without attaching cables? The more I think of building one of these super trailers, the harder it gets. I would rather have one of the flat beds trikes above with hydraulic disc brakes and motorcycle tires. and a large gear reduction to keep the speed down to a legal amount.

This could turn into a popular way to haul heavy cargo up steep hills. You could build one large enough to haul 600lbs with a regular bicycle easily.

I would use one large motor with one large gear reduction not made for speed. Attach it to the center of a simple rear axle. Slow riding will not make the single axle jump around as it would with speed. And finally you will need to adjust the gear ratio after using it long enough to know what you need.

I would then attach the controller to a Pedal Assist Sensor [with the three speed selector functional to help control the speed of the motor], on your bike so you do not need an accelerator which could make the trailer bump against your bike. And you don't really need expensive lithium-ion batteries because you will use this only when you need to haul something heavy.

I would use 2.25"x 16" inch 4 ply motorcycle tires {mounted on 406mm 1.25" wide} BMX rims, because they do not create more rolling resistance until you have a lot of weight on them. And by then you will be using your motor.

I hate bicycle tires they are not made for hauling heavy cargo. And even if you could technically use them, they're only single ply; a misery to change a puncture when loaded with cargo. Don't waste your money.

Axles for HD Trailers

Don't use bicycle bearings on trailers to handle more than 300lbs. Pillow block bearings are the best; two on each axle thick enough to not bend [0.786" or 13/16th" or 20mm is what was used for this trike hub]. Look for Delta trike hubs and axles. It is better to over engineer it than have it break down because you expected people to use a petroleum powered pickup truck. People are going to be using these things for heavier loads than you think. Most people are living in denial that living without gasoline will be far harder that anyone knows.

And remember that 3ft wide is the maximum for bicycle equipment. Motorcycle wheels and tires are very much stronger than anything made for bicycles.