Amphi-Cycle Lets You Ride The Trails, The Waves, And Back Again


Hackaday regular [Berto] is always looking for new ways to get around, and wrote in to share his most recent creation, an amphibious bicycle.

He bought an off-the-shelf inflatable boat and constructed a rig that allows him to stably mount the bike on it. Once [Berto] comes across a body of water he wants to cross, all he requires is about 7 minutes time to inflate the boat and attach his bike. Using a modified version of his electric drill-based trolling motor we saw last year, the Amphi-cycle glides across the water effortlessly as demonstrated by his assistant in the video below.

Right now the boat is propelled solely by the trolling motor and a large lead-acid battery. We would love to see the amphi-cycle powered by its rider, though we don’t know how that would affect the “one boat fits all” design [Berto] is aiming for.


24 thoughts on “Amphi-Cycle Lets You Ride The Trails, The Waves, And Back Again

  1. I don’t want to be mean, but isn’t that bicycle totally unnecessary on the boat? you could just take it as a luggage, without fancy construction around it, and it would float as well or better. It would be more suited to be called a amphi-cycle if it was propelled by bicycle.

    1. There are a few fundamental design issues with the current format of the vehicle. With the rider being upright (as opposed to sitting in the boat next to the bike for example) the wind will have a greater effect than the motor in determining the crafts direction and speed. The motor being centrally mounted with no rudder compounds the issue, as even in very light wind it is clearly hard to keep the craft on a straight tack. I do however like the simplicity of construction and use of everyday available parts. Something that would appeal to a holiday project for a young kid to get into perhaps?

      1. Yes,it has to do with holiday and feeling “the kid in me”. Amphibious cycling is fun stuff. This Amphi-Cycle project is not finished, not in concept nor in hardware. Important is the discussion about concept and sollutions. A lot of stillness around amphi-bikes on cycle/water forums. Finding concensus about the term “amphibious bicycle” is already hard to find. Everybody sees something different for their eyes. Has it be propelled by the cyclist or is electricity and sail accepted? I hope that as already said here a new cycle/water sport is developing.

  2. This is being presented as a finished product, but it seems much more of a prototype to me. There have been several half-finished projects presented here recently. How am I supposed to get excited about work only half-completed?

    Plus, using zipties to secure the frame to the raft is definitely not the way to go. What happens when you get to the other side and realize you forgot to bring along a knife or snips? Looks like you’ll be humping that whole contraption on your back for the rest of your journey.

  3. If used anywhere near salt water it will probably break in a week or so. Also, drills use brushed motors which aren’t that good for continuous use.
    Clever hack anyway.

  4. @RooTer What’s the point of using the bicycle to propell on water? Nothing on a bicycle is made for that or it is very difficult to implement.
    The bicycle exists 127 years. Isn’t it strange that in all those years you can’t buy 1 amphibian bicycle in the cyclestore? Or even an amphi add-on for your bike? My intention is to use a normal bicycle, on wich you can easily pedal to the water side. After a short preparation you can go for a fine ride over still waters. Also fishing is an option. Simple solutions are hard to find!

    1. I think his point is, it’s not so much an amphibious bike, as a bike-transported boat. The bike only functions on water as a seat. Other amphibious vehicles can drive between land and water with no major changes needed, and generally the same propulsion system powers both modes.

      But that said, that wasn’t why you invented this, it seems you just like cycling to the park and boating on the lake, without a trailer or too much encumbrance. The problem it was designed for, you’ve solved well and practically.

      It would be cool though, if you could rig the propeller up to the pedals, and have the handlebars turn the rudder. That would be an actual amphibious bike, altho it’d be much more of an endeavour to take on.

  5. Ok so I have a boat with an outboard motor. If I put my bike in it and cruised around the lake then I to would have an amphibious bicycle and I could probably fit more than one. This is NOT an amphibious bicycle, the name would imply it is a bike that can be ridden on water. This is nothing more than a bike rack for a raft.

  6. This is quite inspirational, actually. Term Amphi-Cycle conjured up a vision of a much different contraption:

    I always liked that scenes in Western movies where riders cross the rivers on the backs of their horses.

    That’s why I believe true amphibious bicycle shouldn’t aim to carry you dry across water and it shouldn’t require modifications or different modes of operation to switch between land and water.

    You should be able to just ride the bike right into the water and then pedal away all the way till your bike’s tires grab the riverbed and finally, the shore, without stopping.

    It would make a base for a nice sport, as well.

    What would it require?

    Probably a pair of floats, mounted slightly above the center of mass of vehicle and rider (for stability), a propeller coupled to the back wheel and a rudder coupled to bike’s handles. A nice addition would be a bow in front, for better hydrodynamics (as well as aerodynamics on land).

  7. Salec, is this inspirational in the same way as seeing a car on a ferry?

    If you type amphibious bicycle into google images you will get hundreds of hits of actual amphibious bicycles/tricycles.

    Look to the argo as a perfect example of an amphibious vehicle done well. From land to water and back with 0 setup time, and no stopping. You just drive it.

  8. This “bike rack for a raft” is a nice one; the bicycle is hanging under the 2 lifting pieces and functions as a counterweight to the weight of the cyclist above. That protects agains tumbling. Zero setup time is the grail but how many of the dozen amphibious bicycles on google images have that? I have to agree with Salec. It would be great to invent a new sport. Please, without competition.

    This Amphi-Cycle

  9. The sophistication of the project has me wondering if the team has done any research on pedal powered boats like the Flying Fish or the Hobie, or even the engineering behind some of the winning Kinetic Sculpture racers.


  10. I have a cycle-car.
    The bike straps to a rack on top of the car.
    You use the car’s drivetrain and passenger compartment when you need to carry a lot of stuff or go fast. You get the bike down and use it when you don’t need the speed or capacity of the car.

    WTF would you want to sit on a bike in a boat?
    WHy not sit on the nice soft boat next to the bike?

  11. Eek. This is not an amphibious bicycle, it’s a bicycle rack for a boat. And a poor one at that.

    There is ABSOLUTELY NO POINT in riding the bicycle in the boat if it is used for neither steering nor propulsion. In fact, it offers only disadvantages. It puts the riders center of gravity alarmingly high. And should the motor’s battery die, good luck reaching the water to hand-paddle your way out!

    Instead, rack the bicycle flat on it’s side, across the front of the boat, with the wheels pointing starboard and port. Then you can sit down comfortably in the boat with your legs underneath the bicycle. No more high center of gravity. Weight is distributed more evenly, with your torso at the back and the bicycle at the front. Since the rack no longer needs to support your weight, you can use a smaller, lighter rack; plus simple (and reusable) velcro strips to secure it. And since you can now freely reach the water, the trolling motor becomes an option rather than a necessity; which you can choose to leave behind to further lighten your gear.

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