Sit on Kayak Pedal System




About: Hmmm...I was just trying out the name to check the availability :( ahh well...they're cool guys! I'm a teacher/tinkerer/outdoor kinda guy. Bamboo is the most incredible renewable construction mate...

Made from a sit on kayak, a bicycle, weedeater and assorted parts, this water-craft is relatively easy to build, great exercise and fun!

Step 1: Gather Materials

1 sheet of 2" blue insulation foam (4 ft X 8 ft) (or sit-on-top kayak)
1 bicycle (or 'Big Wheel' trike)
1 old 'Weed Eater' or weed whacker of any make
1 wooden or plastic model aircraft propeller (mine's 18 X 12 but somewhere in the range of 10 X 10 to 16 X 16 should do)
1 3/8 drive 90 degree drill chuck
various and sundry wood and metal bits to connect it all

Step 2: Construct Foam Pontoon Boat

Insulation foam is relatively easy to work with and makes a utilitarian pontoon boat. (working on Instructable for my new design)
Alternately follow these directions (Dual-Motor SIP&PUFF Controlled Kayak System or

Step 3: Construct Propeller Assembly

Disassemble "Weed Eater" to get to the flexible shaft assembly.
Remove the weed whacker head and attach propeller.

Step 4: Mount Bicycle to Pontoon Boat

Use bamboo supports to mount bicycle to pontoon boat

Step 5: Position Propeller Assembly

Position and mount propeller unit to the bicycle/pontoon boat assembly using U-bolts to clamp it in place

Step 6: Pedal Away

Find a pond/lake/river deep enough for your boat/propeller and pedal away!
(Pictures of finished project ASAP!)



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    11 Discussions


    7 years ago on Introduction

    HI Leon , This is just the thing Ihave been looking for . I want to adapt it to my 3 x 7 foot pvc raft. Instead of the prop Iwould like to use a pvc paddle wheel. Does anyone have a simple plan for that? thanks, tropidavo

    2 replies

    Reply 6 years ago on Introduction

    Maybe you could try something like this:

    or this:

    Just make the blades shorter. Hope that helps.


    Reply 7 years ago on Introduction

    I'd try really hard to use the propeller over a paddle wheel. It is way more efficient.


    6 years ago on Introduction

    This looks great. Could we see the finished project please?


    7 years ago on Introduction

    is this supposed to pull or push you thru the water ?. I hope you continue and take a lot more pics, Ive been considering something like this for a couple years now


    7 years ago on Introduction

    Congrat! I was considering a similar design but decided it was too difficult. I've decided to try a paddle wheel system using a trike.


    7 years ago on Introduction

    Very nice!
    I have been struggling with this for a while and then put the project "on hold" (and continued with my other projects).

    Can you tell what a weed eater is? I'm very interested. Secondly, I have a similar propellor lying around here and I always assumed that it wouldn't be strong enough. Are you using it without any glass fibre / epoxy coverage?

    2 replies
    the cowboybertus52x11

    Reply 7 years ago on Introduction

    Weed Eater is a product trade name for a landscaping tool also called a string trimmer. They work by spinning a length of replaceable nylon "string" fast enough to cut grass and weeds, hence the name Weed Eater. They are used to get close to items in a lawn or in areas that are inaccessible to larger mowers like steep hills.'s a kayak...NOT a pontoon boat but...the foam boat's not done yet so I just put the pedal assembly on my it says you can in the instructable...and there you go! Video soon!