When our BikeBoat hits the streets there’s one question that inevitably comes up: Will it go in the water? The answer: Yes, it goes in just fine. Getting it out is another story, since it sinks pretty quickly. If you want to start a human-powered kinetic derby, a BikeBoat that you “pedal” by rowing is as good a place to start as any.
The derby in question is the Menagerie in Motion Kinetic Derby, which will be part race and part spectacle, with whimsical human-powered vehicles traversing roads and obstacles like mud, sand, hills, and (in the future) even water! Our goal is to enchant the hearts of Alachua County residents and the southeast with the magic created through making and riding folly-filled vessels of fantasy.
Test run with the Bike Boat. Looks to me like the horseshoe crab is going to be hard to beat!
Posted by Raymond Rawls on Saturday, December 12, 2015
Here’s how we made the first derby’s first entry:
Starting with the Right Supplies
This project benefited greatly from finding a used bicycle originally designed to create movement through rowing versus pedaling. Our friends at the local rowing club saw a terrible Sketchup representation and provisioned a kayak for the project in spite of the image.
It is a bad image, but a great way to keep the goal in mind. This single image really helped us see where we were rowing.
Let the Cutting Begin
We taped off a cut area after a great deal of of measurement, some general assessments of how the two pieces would interact, and a few assumptions. The assessments were critical because they forced us to reevaluate things like boat positioning to allow for the wheel to turn properly, the center of gravity impact that would cause, the kayak’s natural center point, and the stroke length for the captain of the vessel. After roughly an hour the cutting began and there was no turning back.
Seating a Boat on a Bike
To sit the boat on the bike we had to do a few things. We removed the sliding seat, stationary foot holsters, and eventually cut an additional hole for the top of the front wheel assembly in the bottom of the boat.
With the boat resting on a less than 3 inch wide section of aluminum I-beam, it was necessary to create some cradle supports for the boat to spread weight. A smaller piece was created to keep the front stable, however a longer cradle was needed under the formed seat section of boat to account for the driver’s weight and to capture their movement. In the final stages we would also go back and foam fill the cavity between the bottom of the boat and the formed seat.
Hold Up (Your Feet)
Next we attached the foot holsters from the bike to the boat based on the body of the intended primary driver. They are bolted on with an interior metal plate to disperse stress from foot pressure over a greater area of fiberglass. We then fiberglassed over that plate and bolt for additional support. The same measures were taken for the previously noted cradle bracing.
Outriggers — Because BikeBoats Don’t Have Training Wheels
We tore down a donated wheelchair and used leftover metal from another project to wield a rough base stabilization feature. The aim was to account for the higher center of gravity and the additional forces exerted from the now elongated combined form.
Three Way Supported Stabilizing for Outriggers
The stabilization is bolted at the bottom of the bike’s I-beam and the rear wheel, and coupled at the chain stay.
Covering Our Cuts
We had a friend sew a canvas covering for the row mechanism hole, leaving space for the unimpeded rowing of that mechanism.
We took the boat out prior to it’s first official event and allowed local residents to try it out and garner feedback. And when we say public input, it does not get more public than the City Public Works Planning Manager. Her input, along with others, helped establish (among other things) that we needed to add additional bracing for the foot holsters to allow them to take force from riders, especially for uphill thrusts.
Greater speed is achievable with the additional foot support you can see pictured here. Besides being useful for hill climbs, which is a bit like rowing up a waterfall, the added structure allows the captain to provide the power necessary to maneuver tight ceaseless turns, also known as donuts.
The final challenge for this showboat will come in the Menagerie In Motion Kinetic Derby. You can go to our website for more information and to see other entries.