A simple way to make an amphibian bike is by using inflatable floaters. I bought a rubberboat and removed the soil. The frame, what keeps the bicycle in position, can be taken apart. The lightweight inflatable construction can be carried to the waterside at the bike as a long roll.
This Amphi-Cycle is propelled by a simple inboard motor, using a cordless drill, powered by a large 12V battery. I found out that other ways of propelling are too complex and expensive.
This is a low-tech project, so no welding or big machinery is needed. Everyone can use his or her own bicycle to make it amphibious. The conversion time from land to water takes not more than 7 minutes.
Step 1: Video
- Detachable floater construction
- Easy to carry at the bicycle
- Quick set-up on the waterside
- Easy propulsion by a cordless drill
- Floater filled by an electric air pump
- Stable navigation on water
- Extreme fun
Step 2: Construction
It's easy to buy a cheap inflatable vinyl boat, where your bike fit's in. Cut the bottom out and make a ring of PVC tubing on top, this to spread the weight equal over the boat. The core parts are the lifting pieces, under the saddle and under the steer. They are made from concreet plywood and steel pipes. No welding and no big machines are used. Pop rivets (poor mens welding) I used for the inboard motor. The bicycle rests with 4 steel pipes on the top ring. The pressure is straight down. Saskia, the testpilot, said that she was feeling quickly save on the water, this by the stability of the frame. The surprise was that the high gravity point of the cyclist was compensated by the bicycle hanging under the 2 lifting pieces. It's as a counter weight that gives the stability on a floating mass.
Step 3: Electric 'inboard Engine'
When using the pedals for propulsion, I had to make a complicated mechanical construction. For that reason I made a simple 'inboard' motor with a propeller driven by a cordless drill. This can be made within an hour assuming you got the right materials and tools. A 12V gel/lead battery feeds a cordless drill. This drives a propeller via a square drill head. The drawing and photo's are showing the construction. The floaters are filled and deflated with an electric air pump. A powerstrip makes 12V power supply easy.
Step 4: Conclusion
For this project I had to make a ship dock to test the stability of the floater construction. Making the lifting pieces, under the saddle and under the steer takes some time. The plastic tubing on top of the floater bends under the weight but will stay stable. Steering with the inboard motor needs some learning. All in all; it was a great moment to see that it is possible to drive within minutes in our town pond. This is a low-tech project giving a lot of fun, to make, to bike and to navigate over still waters.