Any tips for building a bike trailer?

A local guy built his own pedicab without welding and using recycled materials whenever he could to keep costs and complexity down.

It’s not an exact match for what you’re doing, but might answer some of your questions.

Look on eBay or Craigslist and buy one instead. If you don’t know about the technology of construction or the processes that will be required for successful completion of the project, then it’s unlikely that you will produce a safe and effective vehicle for less than you can buy one on the open market.

Don’t forget that anything that you plan to use for transport on public roads has to pass your jurisdiction’s rules for such vehicles, which are not always user-friendly.

I don’t know that accordion safety is a real concern for most cities

@funkdaddy I guess you’ve never been to my city :)

I cannot help you with the construction, but thought I would give you a reminder that some states require a plate on trailers. My state doesn’t, but we got one, because when we travel to states that do require one, you must have a plate.

For the basic structure, you might consider using PVC pipe. It’s cheap and easily available (any Home Depot sells it). You can easily cut it using a handsaw, and assemble it into any number of configurations using PVC pipe fittings and glue. The structure would be cheap, light, weather-proof and strong. I see on the web that there are lots of people who have already done this. Here’s one guy’s version.

You can get 16” semi-pneumatic wheels (plastic mag style) w/bearings from McMaster-Carr for $16.60 ea. Those take a ½” diameter axle.

I like this guy’s idea for a cheap and simple hitch.

It’s clear that I’m building a trailer for my bicycle, right? My bike doesn’t have a plate…