Bike trailer transforms into a cargo dolly


January 4, 2013

The Convert, in dolly and trailer modes

The Convert, in dolly and trailer modes

Image Gallery (3 images)

If something is big and/or heavy enough to transport on a bicycle trailer, then it’s likely also unwieldy to carry by hand. Well, that’s why the Convert was created. It’s a bicycle trailer that can be converted into a cargo dolly.

The device was invented by industrial designer Joshua Brassé, who was also behind the Incog multi-tool. When in trailer mode, the Convert attaches to the bike’s rear axle using a standard hitch and pin. At this point, the trailer’s moveable wheel axle is situated towards the middle of the unit, in order to support the cargo’s weight most effectively while being towed.

Once the cyclist reaches their destination, the Convert can be quickly unhitched and tipped up on its back end. Its axle is then released and swung down, so that the wheels are in the proper place to allow it to be used as a dolly. The cargo can simply be left as it was when in trailer mode.

Although the images seen here are renderings, Brassé informs us that he has built a working prototype of the Convert. He is now attempting to raise production funds on the ideacious crowd-funding website. A pledge of US$5 will get your name on the list to purchase a Convert of your own, which will cost you an additional $585 when and if they reach production.

Source: ideacious

About the Author
Ben Coxworth An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth

interesting idea, although im not sure its so much of an innovation for this to be of significant use in the real world. I dont really know for sure though.. this seems like it would be good for people who delivered stuff via bike, i know bike couriers exist but im pretty sure that weaving in and out of traffic with a trailer/luggage thing wouldnt work well.


Ridiculous. Those wheels are far too small to make an effective bicycle trailer, especially under a load of any weight. The slightest pothole would jerk the rider around terribly, and maybe even off the bike.

Anne Ominous

re; Anne Ominous

While I agree that bigger tires would be better I have pulled a heavily laden radio flyer with those narrow 8 inch tires without that kind of problem.


It's worth testing. It's a common issue to have to carry heavier/bigger stuff when you live in a city and only have a bike to move around.

Freyr Gunnar

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Bruce Miller

Great idea with a silly price. sell it for $25 more than a regular handtruck and you would sell a lot of them. At over $500 you could get a local welder to modify a $50 handtruck to do the same thing and have a couple of hundred left over.

Michael Crumpton

Does seem grossly overpriced, but I don't see it would be a major problem re-stability. After all, most potholes are not that deep, and the weight on the trailer shouldn't be great enough to cause more than a hiccup.

However, it would be better still if the axle, when moved forward to act as a bike trailer, could be positioned on the end of a leaf spring so that it would deflect in the event of contact with a pothole, brick, etc, and if the coupling could allow for rotation (assuming it doesn't already).


Hey Arahant, thanks for the comment.

Over the past few years there's been a huge bike, e-bike, scooter, and subsequent lightweight trailer boom here in Toronto. I've got a bike that has been my companion for over a decade, and a Honda Ruckus - both are my go-to's when I'm whipping around the city. The idea for the convert was born of necessity, and the combination dolly/trailer made sense to me, not only for those 2 functional purposes, but also, it means that I don't need to have/store 2 relatively big/bulky objects in my small living space, and I've really grown to hate moving - especially when I've got to deal with stairs (I've moved home or office close to 10 times over the last 10 years).

I mocked up a working prototype, and have been really happy with it. Traffic hasn't really been an issue (city drivers are getting pretty used to seeing these things)... I've definitely got more compliments on it than haters! Hauling my hockey gear gets the most smiles for sure.


re; Anne

Hi Anne, I can see how you might think the wheels are too small (actually the wheels in the renderings are a little smaller that the prototype), but we've used those so that the function of the dolly isn't compromised.

Once in production, we'll be testing the size to have the perfect balance between the 2 functionalities.

I know that bigger wheels would be better, but IMO it's a small compromise for the added benefits.


Re: Freyr

Thanks Freyr. I'm loving the prototype, it's working out great. We'll be going into production shortly too. Can't wait!


RE: Michaelc

Thanks for you comment Michael! I know the price seems high, but we've done a fair amount of market research, and have got quotes back from a number of local and offshore manufacturers... the retail price is appropriate in order to make a high-quality product (we've decided to have it made locally for multiple reasons).

I think a handtruck mod is a great idea (that was my first prototype) for those that want to save a bit of money.


RE: bergamot69

Thanks for your comment! I'm sure as our volumes increase the price will be able to come down a bit, but like I mentioned to Michaelc, we really want to make a great, locally manufactured high-quality product - the result is always going to be a higher price tag. It's the cost of green (and keeping work in North America) right?


The Burley Travoy cargo trailer can be used as either a dolly or bike trailer but is available now at half the price. Burley is a well known maker of bike trailers and offers a variety of optional accessories for the Travoy (which also folds up into a tiny package when not in use).

Lawrence Lagarde

Overall, this is a good idea. However, $590.00 is simply off the wall. For this to succeed the price needs to be something like $100. A price that approaches or exceeds the typical median price of an entire bike is simply a deal killer.


The swing axle is interesting, but a quick-off hub and one or two points of re-attachment are also an option that could save some dollars. I wonder about putting brakes on the trailer wheels, but that may be too costly and crazy (I am not a regular biker).

Bruce H. Anderson

RE: Lawrence & StWils,

Thanks. We'll be working to bring the price down, but won't be compromising on quality or functionality.

I really do appreciate the feedback!


The Burly may work as a dolly, but not as a hand truck. The difference being that a person can tilt the load and get the plate underneath and out again with a hand truck, rather than needing to lift the load on to a dolly. A duffle is easly enough to handle, but try to move a 150 pound crate.

Bruce H. Anderson

Why not just have the smaller wheels mounted permanently at the bottom / back, and the larger road wheels as shown.. No moving wheel / axles?..

Bob Siegel

I think this is a good idea. I've sometimes found it useful to use my old Cannondale Bugger 3 child/cargo trailer as a hand trolley. I've never had problems with its 20 inch wheels, and I currently ride on 16 inch wheels by choice. The world's fastest upright bicycle uses 17 inch wheels. The only real problem I've had with small wheels was when I rode straight into a 10 cm kerb at 25 km/h. The wheel was undamaged, but it broke my front forks. To minimise drag, the trailer should use high pressure tires. As for the price, it's a matter of (a) what it costs to produce a design of a given quality and (b) whether your needs are specific enough to justify a particular design.

Leon Arundell
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