Friday, September 14, 2007

Hubless wheels: Does the wheel really need reinvention?

Franco Sbarro, Italian genius who pioneered the hubless wheel...
Mention motorcycle wheels, and most people will picture a regular alloy wheel, complete with the hub and the spokes. For most, the hub and the spokes are an integral part of the wheel and people can’t usually imagine that a wheel can actually exist and work without these.

Not Franco Sbarro, a mechanical engineering genius from Italy. Born in Italy in 1939, Sbarro moved to Switzerland in 1957, and is widely considered to be the ‘inventor’ of the hubless wheel. He did not, of course, ‘invent’ the wheel, but he was probably the one to believe that a wheel – without a hub and spokes – could be put to actual use in motorized vehicles. Sbarro designed a few concept vehicles around the hubless wheel, though none of them took off due to the practical, real-world drawbacks and difficulties associated with manufacturing and using hubless wheels.

Over the last two decades, there have been various attempts at using hubless wheels on motorcycles. Most haven't worked...
Others have tried to follow Sbarro’s example, but with little or no commercial success. Based in France, Dominique Mottas and his company, Osmos, have worked on hubless wheels since the early 1990s. However, as far as we know, nothing much has come of it. In theory, hubless wheels are supposed to offer various benefits over regular wheels – reduced unsprung weight, fewer engineering constraints, better braking and steering and improved packaging.

Hubless wheels are expensive and difficult to adapt to regular bikes. Not that it stops people from trying anyway
Pic: Flickr
In the real world, problems associated with manufacturing tolerances, engineering suitable drivetrain, suspension, and braking systems and wheel assemblies being prone to jamming and/or failure, have meant that nobody has successfully reinvented the wheel yet. And that’s the way we suppose it will remain, in the foreseeable future!

They look cool, but hubless wheels on motorcycles haven't worked because of mechanical complexity. Don't expect a hubless-wheeled GSX-R anytime soon!


Karl Sánchez said...

what about the mechanical wear?
I think a small bearing in the center of the hub is to rotate at the same angular velocity (rpms) as the big wheel it is on, while on this hubless wheels the bearings must be spun faster (way faster, since the track is hughe compared to your standard axle), if memory serves, the skateboards used in high speed fail usually because the wheels melt from the added strain on the bearings.

Anonymous said...

Instead of bearings why not just use magnets?

Gems Mattis said...

Yah I agree, use magnets or copper windings with an electronic charge that separates the rim from the actual hub.
The engine will drive a 5000 watt generator, simple.

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