One of the problems of being a cyclist is that a bicycle just isn’t designed to carry much more than a human. You can get panniers and hang shopping bags from the handlebars, but sooner or later there’s a load which just doesn’t fit. At that point there’s only one way forward that involves staying on two wheels: find a bike trailer. If you fancy building one yourself, then there’s La Charette (French language, Google Translate link), an open-source three-wheeler design from France.
Construction is a sturdy welded box section tube spaceframe, with the single wheel at the front providing steering, and a towing bar attached to the seat post of the bicycle. Along with the impressive load capacity comes the problem of towing it, and for the cyclist with less-than-superhuman strength there’s the option of an electrically-driven front wheel. Stopping the whole thing is an essential feature with loads this size, and to that end there’s an inertial braking system operated by the force on the towing bar.
All in all it appears to be a useful trailer, albeit on the large side for storage when not being used. It’s certainly one of the larger bike trailers we’ve seen, though not perhaps the most stylish.
Thanks [Jeff] for the tip!
There’s a moving company here in Montreal that moves by bicycle. Obviously multiple trips. I think no special bikes, just trailers.
It looks similar to https://www.carlacargo.de/ and that rides like a dream so if the force sensor setup is not too different then I would recommend this any day.
When riding in the city the most important part for a good heavy load bicycle trailer is the brakes and a motor that is responsive to frequent stops and starts, there is lots of documentation on how that is done on th Charrette https://framagit.org/Veloma/Charrette/-/tree/master/Electronique
Apparently Carla Cargo has a Open Hardware variant but that does not include brakes. https://en.oho.wiki/wiki/Carla_Cargo_Crowd
Add some smarts in the front, and you could dispense with the linkage between the bike and trailer – ie the trailer would just follow a marker on the back of the bike (or rider).
So, one could replace an iron bar with a heavy duty computing system for orders of magnitude more money, losing all fallback options, longevity, low maintenance, repairability and reliability on the way — but why?
IMO IKEA has the best solutions. Their motorized bike trailers have strain gauges in the connecting rod, which essentially make them “weightless” to the biker.
Southeast Asia has been doing this for a while now.