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Bike Boat needs some help Answered

Hi, fora raft race contest for charity i would like to design something like this:
for two people!
It has to be made from bits that can be readily available and for not too much moneys because the more cash that goes into the build the less there will be for the charity organising the event.
Just wondering if anyone had any ideas, mostly for building the wheels, as, i hope the frame can be made from a modified bike.



Those big wheeled things aren't really fast -- at least, I've never seen one move with any appreciable speed as compared to a paddle boat like the one in the picture.... As far as making such big wheels.... fiberglass comes to mind, but that will be pricey :/

ahh didnt realise they were slow, i figured you needed to have floats aswel as propulsion in the water = more water resistance.
so i figured that one of those would be more efficient, another of my ideas would be one of these:
but ideally i would be able to make it from blow up sections like the pro ones. Any ideas how to make something like this?

The "paddle" area of the trikes, is not large enough to propel very well, thus the slow speed from that. The Shuttlebike looks really cool though. I am not sure, but it almost looks like the paddles on that are driven from the back wheel sproket to a drive that goes to both platoons. Are the paddles under each platoon then? That might make it a little more difficult to build. And is the steering mechanism really only a small rudder attached to the front wheel? It seems to turn very well for that being the case. I was wondering if turning the wheel didn't also effect the speed of the paddles on the side being turned towards. Ok, I am done blathering and thinking out loud for now.

ok, from what i've seen from other vids i can see the back wheel having some sort of wheel on it that drives a flexible cable that takes the drive down to a propella on the front wheel (attached to the bottomg of the rudder) hence the amazing turning circle.

That would appear to be the case...
Here's what the kit includes...

Notice the shaft that the rear wheel spins on -- and the transmission on the end (likely just bevel gears). Flex shaft goes forward to the front assembly/rudder and a little plastic prop...

there's a fair bit of engineering in there - especially in how the bike frame is supported (rear wheel and down tube). I'll bet it's doable :p Hell, use large PVC pipes for your pontoons -- then you don't have to worry about making an inflatable structure that can hold a bike on 4 points :p

yeah that was my other idea, although inflatables would be cool if anyone can think how, also what would be best (this will have to be for two people), bikes side by side, or, end to end?

PVC inflatables are made by vulcanizing (I don't think that's the proper term when you apply melting heat to PVC) the PVC cloth - effectively welding them together. The ends of the tubes are sealed with a plastic cone on the inside and a plastic cone on the outside that is both glued (with sealant) and screwed (without penetrating the pressurized area) together.

For two people.... Here's the pro/cons

Side by side
-increased side to side stability
-less front to back stability (if the length is the same as if it were made for 1 person)
-less total flotation
-less aerodynamic (good in tail wind - really bad in headwind)

tandem - end to end
-increase flotation
-less side to side stability
-increased front to back stability
-less cross wind aero (wind will push you from side to side)

The irony is - before you posted this, I was reading the adventures of greg blog about his pedal the ocean challenge

Human Powered Boat

I imagine you could modify a canoe to use a similar drive train.

If you haven't seen already


I like HPV stuff in general :D

thanks for the replies! unfortunately i don't believe canoe's are allowed to be used in the construction (by the fact we got told of last year when our build used two of them!). Cudn't find any instructables around this area either so would be good for me to document mine for other users!

bump! still need some help ppl!

Flotation, maybe inner tubes of tires (cars, trucks).
Propulsion, perhaps a wooden rig much like the paddle steamer. Two bikes side by side driving one rotating paddle.

that was somthing like what i was going for, but that'd be alot of inner tubes

If you've got a trike frame, get a couple of big plastic barrels (water butts, chemical drums) and drill a ring of holes around the top of the lid. Use cable ties to fasten the lids to the back wheels, then caulk the holes (silicon, hot-glue, whatever) and put the rest of the barrels back on the lids. Add paddles to the outside of the barrels as desired.

A couple more barrels strapped to the front forks will hold the front end up.


Don't rely on the wheels for buoyancy at all - just add paddles to them, then strap on barrels, foam, lumber, whatever to make the bike float with the axles just above the water-line.