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Wheel Survey - Feature comparison

Wheel Survey - Examples

	Bike wheels. Rex
	Triple bike wheels. Grendel
	Wrapped bike wheels. La Nina
	Big spoked wheels. Tiki Torchure
	Plywood wheels. Grendel
	ATV wheels. Rex
	Foam plastic wheels. Gold Diggers
	Plastic shell wheels. We Stink
	Agricultural wheels. Maltese Fulcrum

The Ideal Wheel

• Ideal road wheel Gives low friction and absorbs minor bumps. Follows the road surface for good traction. Strong for both vertical and side forces. Example: high pressure bicycle tire.
• Ideal mud wheel Deep treads. Large diameter to width. Example: agriculturale wheel.
• Ideal sand wheel Does not deform the sand surface. This implies a very low force per surface area. Deformation of the tire should be gentle to reduce digging in. This implies large wheels diameter. Example: truck inner tube.
• Ideal hardpack wheel Durable. Absorbs large vertical changes quickly. Wide to avoid getting stuck in ruts. Example: agriculturale wheel.

The all around ideal wheel would have low rolling friction on the road - implying high pressure neumatic. It would not deform sand - implying very low pressure neumatic. In mud it would provide good traction without getting bogged down - implying narrow with deep treads. On sand it would float - implying wide with no treads.

There is no such thing as an all around ideal wheel. This leaves two possible approaches. Either you transition between wheels, with each wheel type optimised for its own conditions. Or you accept that you are not going to be as fast on most (or all) terrains as tires optimised for them.

Disclaimer

I have filled out this table with a combination of measurements, approximations, opinions, and guesses. You might think that I could put down exact numbers for cost. But cost is a function of how much you are willing to compromise. Bike wheels from the junk bin are available for free, altho you may have to spend a bit on the tires and inner tubes. ATV wheels are usually not free.

Road speed is often a function of the rest of the vehicle. In some cases I had many examples to suggest a top speed. In the case of the agricultural wheel, we only have one example, and it is difficult to know if the top speed is a function of the transmission design or the wheels. I am guessing it is the transmission, so I roughly doubled the Fulcrum speed for its wheels listing.

Summary

The purpose of collecting this information is less for imparting wisdom than it is for getting you to think about all of the tradeoffs. Nobody has all the answers. Kinetic Sculptures have been evolving for over 30 years. All parts of these machines continue to evolve. But I consider wheels to be the least well addressed of the many design challenges of creating an effective all terrain human powered vehicle.

For more information on wheel design, please see my 1999 presentation .