Sep 8, 2009

Chasing New Technology

A friend sent me a link to this picture as a comment on something I'd said a while back. If you look closely, you'll see that the carbon fibre front wheel disintegrated and the tire stuffed itself between the front fender and the forks and what was left of the wheel. I have no idea where this happened and under what conditions, but it's a pretty interesting look at what pushing the edges of available technology can produce.

A lot of racers have sacrificed their bodies to provide giant steps in technology over the years. Sometimes, the failure of one technology produces a completely different modification in the state-of-the-art, as when Roger DeCoster's Suzuki semi-experimental forks let loose during a 1975 Trans-AMA motocross and DeCoster suffered serious injury from the resulting face-plant. When he came back from reconstruction surgery, he was wearing a full face helmet and started a revolution in personal protection for motocrossers.

One of the good reasons some riders are so hung up on vintage bikes is that the technology is "proven." A bad reason for the same decision is that the proven technology is so far behind the state of the art that the proven stuff is dangerous; drum brakes, for example. Ignition points might be another example of deeply flawed historic technology, based on modern ignition systems and their reliability.

This last week, my wife drug me to the state championship high school rodeo at the Minnesota State Fair. Having grown up on rodeos, I was surprised to see all of the protective gear some kids were wearing. I like the change, but it's a long way from the "traditional" cowboy look. Helmets, armor, high tech shoes, and ropes that hold a loop even when they are dangling from the saddle horn, all stuff my older rodeo-riding cousins would probably spit on.
Everything changes. Some changes are painful. Some are easy. Some make sense, some ideas that look spectacular on blueprints turn out to be freakin' idiotic in application. As for motorcycle wheels, I still like aluminum wheels with spokes. Ideally, the wheels would support tubeless tires, but I can live with tubes. Someday, I suppose, I'll end up on a bike with plastic wheels and I'll like it.

1 comment:

  1. That wheel looks as though its left flange came off. If the tire had been stuffed by rotation, it would have to be turning backward! The flange is definitely a weak point, but I remember one of the first wheels for Honda single-sided swingarm being bent in a practice at Brainerd WSB. At the time I retired it, my rear WM-5 Hannetrack-Monobrink cast mag wheel was full of cracks. Current Marchesini forged road racing wheels are as thin as 1.5-mm in places, according to their manufacturer. One thing driving wheel evolution is the rapid development of higher-strength magnesium alloys by the auto industry, which has to make things like seat frames out of the stuff. In the bad old days there was AZ31B. Mag wheels were preferred in MX at one time because the available alloys bent rathr than broke on impact - kinda nice.

    Nothing happens any more in US general aviation because all existing designs are fully "sued-out" and nobody wants to restart that cycle by offering a new product with unknown failure modes. That's the good aspect of well-understood technology.

    The other side of that coin is piston engines vs turbines. At the end, a brand-new factory-fresh P&W R-2800 would go 3000-3500 hours before overhaul, and a Bristol Hercules maybe 4000. Rebuilds maybe 2500-hours. But today turbines normally are on the wing 25,000 hours and they are talking about pushing this to 50,000 - essentiall same as airframe life. Car engines are giving 5000-hours and sometimes more, helped by their very gentle duty cycle that spends most of its life under 10% power.

    I wonder what to do with all my cameras that use film, including an old Speed Graphic and a late-1930s Contax. Film? What is FILM?

    KC

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