There are plenty of other great bicycle trailers on Instructables, but I thought I'd post my own. Some of the key points: no welding is required for this trailer, and it is built (mostly) from items from Home Depot and spare bicycle parts.
This trailer was built over time, with a couple of iterations. A few times in this Instructable, I'll use the phrase, "Ask me how I know..." Most of these lessons were discovered during failures of the trailer on the road... these were cases when "the wheels coming off," is more than a figurative phrase.
Also, I make no claim that my solutions to these problems are the best or only way of solving them. However, in the spirit of Instructables being "open-source hardware," feel free to choose, mix, and match these solutions to your favor.
This trailer was built over time, with a couple of iterations. A few times in this Instructable, I'll use the phrase, "Ask me how I know..." Most of these lessons were discovered during failures of the trailer on the road... these were cases when "the wheels coming off," is more than a figurative phrase.
Also, I make no claim that my solutions to these problems are the best or only way of solving them. However, in the spirit of Instructables being "open-source hardware," feel free to choose, mix, and match these solutions to your favor.
Remove these ads by
Signing UpStep 1: Overview & Anatomy
There are several portions of this instructable, so I'll start with an overview of the steps and the parts of the trailer.
Main body: the body of the trailer is a plastic bin with a lid; I used an Akro-Mils Nest & Stack Tote (NST) Model 35300 (29 1/2 x 19 1/2 x15)--I bought mine at Grainger. I like it because it is pretty intrinsically strong and stiff. However, I think this plan can be adapted to most plastic bins.
Wheel mounts: the wheels are mounted to metal brackets on the sides of the container. They are adapted from brackets from Home Depot, with some cutting and drilling.
Internal Structure: the plastic bin is not strong enough to support the wheels (ask me how I know), so an internal frame is needed to hold everything together. It connects the wheels to the bin, and the bin to the trailer connection.
Hitch (trailer side): to connect to the rear wheel hub, the hitch needs to take a right angle and come in at roughly 45 degrees to the axis of travel. Therefore, when you make a turn in one direction, the hitch comes in roughly parallel to the rear wheel. There is a flexible coupling (rubber tubing) to allow turning. The connection to the rear wheel is made using an air hose quick-connect.
Hitch (bicycle side): the connection to the rear wheel to the trailer is made out of a metal bracket with an angle that matches the hitch, which remains semi-permanently in place on the bicycle (you can remove it, but you will need a wrench). It doesn't add much weight, so I leave it on all the time.
Main body: the body of the trailer is a plastic bin with a lid; I used an Akro-Mils Nest & Stack Tote (NST) Model 35300 (29 1/2 x 19 1/2 x15)--I bought mine at Grainger. I like it because it is pretty intrinsically strong and stiff. However, I think this plan can be adapted to most plastic bins.
Wheel mounts: the wheels are mounted to metal brackets on the sides of the container. They are adapted from brackets from Home Depot, with some cutting and drilling.
Internal Structure: the plastic bin is not strong enough to support the wheels (ask me how I know), so an internal frame is needed to hold everything together. It connects the wheels to the bin, and the bin to the trailer connection.
Hitch (trailer side): to connect to the rear wheel hub, the hitch needs to take a right angle and come in at roughly 45 degrees to the axis of travel. Therefore, when you make a turn in one direction, the hitch comes in roughly parallel to the rear wheel. There is a flexible coupling (rubber tubing) to allow turning. The connection to the rear wheel is made using an air hose quick-connect.
Hitch (bicycle side): the connection to the rear wheel to the trailer is made out of a metal bracket with an angle that matches the hitch, which remains semi-permanently in place on the bicycle (you can remove it, but you will need a wrench). It doesn't add much weight, so I leave it on all the time.
Visit Our Store »
Go Pro Today »
For those who may venture into either making a trailer or buying one, may I recommend new trailer users need to practice on a quiet traffic free road.
Please remember:
Bikes for pulling trailers need good brakes.
Load the trailer as close to the axle as possible, keeping the centre of gravity (c of g) slightly forward of the axle.
Keep the load as low as possible.
Secure the load properly so it cannot move.
Please keep your speed down.
Think ahead and brake early and slowly, avoiding harsh braking.
Do NOT use the rear brake. (To avoid jack-knifing).
And keep your speed low. The heavier the load, the slower the tow. For a reasonably heavily laden trailer, keep the speed to NO MORE THAN 10 mph.
Handling problems
Trailers follow a tighter turn radius than the rear wheel.
Making S-turns will almost certainly capsize a trailer.
Trailers can roll, especially when turning and braking, or when turning too fast, or turning and the inside trailer wheel hits an obstacle or a pothole, or turning combined with adverse camber, or turning and an improperly secured load.
Keep the centre of gravity as low as possible and forward of the wheels. Weight too far rear can lead to pitching and yawing, rear-wheel lock-up during braking and consequent jack-knifing and loss of control. To reduce the chances of jack-knifing, DO NOT USE THE REAR BRAKE.
Tyres need to properly inflated, soft tyres can lead to speed wobbles yawing and rolling-over.
Take care to ensure that the wheels are parallel, or the tyres will wear excessively. Excessive tyre wear is a sure indication that the wheels are not parallel.
The hitch featured here will remain attached to the trailer even when the trailer has rolled. This could have serious consequences in traffic. My trailer has a hitch which de-couples when the trailer rolls-over. My commercially made trailer is a 'Der Roland' and I would definitely NOT buy another Der Roland or similar type if I needed a replacement.
The Der Roland trailer can be seen here http://www.bikesandtrailers.com/bike-trailers/roland_roland.html
If looking for new trailer, I would look for a two-wheeled type, rear axle hitch, wide track (the distance between wheels) and a load platform as reasonably low as possible. In-fact virtually identical to the trailer presented in this Instructable. My only DOUBTS CONCERN THE HITCH which will cause the trailer to remain attached to the bicycle after the trailer rolls-over, which is inevitable and may cause the rider problems in a number of circumstances, assuming that the trailer is fully-laden when it happens.
If you hear banging, IMMEDIATELY brake slowly and stop in a straight line. Probably caused by an inadequately restrained load, under inflated tyres, too high a centre of gravity (c of g). The banging sound lasts only a few seconds and IMMEDIATELY PRECEDES A ROLL-OVER. The banging noise is caused by the wheels of the trailer alternately lifting off the ground and crashing back down.
On even a slight almost imperceptible slope, a laden trailer can easily topple a bike off its kick-stand, or pull it away from a leaning-point. Consider chocking both trailer wheels, before loading or unloading.
Another modification was to not loop the conduit but to use only one 45 degree angle so that u-bolts could be used to fasten to the trailer and allow adjustment for wheel height in order to achieve a level trailer. When tightened the u-bolts hold good enough to keep the trailer level. A hole can be drilled through the conduit once the height is adjusted but was not necessary even with a 200lb load. I did a completely different deal to get pitch and raw by using square tubing with the coupling still used for roll. Pictures won't upload here, had to add links. Instructable later maybe. Good work.
hitch wo/roll control
u-bolt leveler method