Sunday, December 16, 2007

Where'd you get those tires?

The most common question people ask when seeing Unwheeldy is, "Where did you get tires for that?"

Big wheel


Well, from a bicycle shop (the late BikeSpring) of course. Alright, they don't really carry 339x2.5 tires, but then again the rim we're working with here is itself a tube, so it's not like a normal clincher tire will work. Or will it? Why yes, with a little surgery. The solution is to take normal mountain bike tires, cut them open, cut the bead off, and straighten them out so they have a larger diameter curve. The tire's response is sometimes to twist itself into a spiral, but with a little force it'll stay reasonably straight.

The idea was to glue on the tires; the first pass was done with Goop adhesives, but it's a bit hard to work with in volume so we stopped and used zip-ties... which don't prevent twisting much at all. More recently, we used neoprene contact cement, easy to work with as you can see in this short video of Jon and I gluing on the tires for one wheel, 4.5 tires per tire.

Sunday, October 14, 2007

Recent events

Unwheeldy has been to Burning Man and several local events in Palo Alto. In a few cases we joined up with the buscycle, such as the finale of the Palo Alto Walks and Rolls week and a store's Harvest Fest. There's sure to be various pictures of these events on the internet, some of mine are mixed in my related collection of pictures.

There are some more pictures from Jean-Luc Brouillet and Jon Perkins who helped tow the vehicle to these events on the quad bike constructed by and on loan from Jay Bain.

Building Unwheeldy

Dave Hershberger built the original Unwheeldy for as a Kinetic Sculpture Racing vehicle. In 2007 he decided to revisit the design and make something more direct. With direct drive. At some point along the way, I started helping him (along with a few other of his friends) and took some pictures, which assembled nicely into a movie:

(1:13)

Fundamentally, the wheel is a bicycle wheel. A five-cross sixty-spoke nine-foot diameter bicycle wheel wheel. The rims are aluminum tubing, bent (it takes about 1 1/2 pieces of 20' tubing for each wheel). The spokes are spoke wire, with a peened head and the other ended threaded to 56 tpi. Threading them was perhaps the riskiest part of the project, with the final solution coming into place pretty late: find a local bike shop with a Phil Wood spoke machine, having them form 1cm of thread, then using a Hozan thread chaser to form another few centimeters of threads--the small tool could not reliably start threading. Then it was a matter of building it with the previous hubs.

Frame building was more straightforward, done with a judicious combination of careful pre-planning and improvisation.

Saturday, October 13, 2007

Unwheeldy

Unwheedly Two is a giant dicycle created by Dave Hershberger and Matthew Blain.



Riding it is an exercise in cooperation... and a lot of fun.