PHOTO CAPTION: George Georgiev's Varna Diablo human-powered racer

Toward Better Bikes, Better Health, Better Planet

Whether its a conventional bike, a recumbent or a velomobile, electric-assist can make cycling an alternative to motoring.

Published: 30-Nov-2008

Today's bicycles are only slightly better than the ones made a hundred years ago, partly because of restrictions that try to keep the races as purely athletic events. In 1975, the International Human Powered Vehicle Association was started specifically to recognize the record set by a streamlined bike. Experimental racers soon established that it was better to sit behind the pedals to reduce the frontal area and wind resistance. That made them more comfortable. They also added a streamlined body, getting even more speed, plus weather protection and enclosed luggage space. Then they found that a third wheel was needed for stability in crosswinds, making a trike that is also safe on slippery road hazards. I decided that if the quest for speed had brought four advantages for daily use, there should be a consumer version available. You can now get on the waiting list for any of a dozen advanced velomobiles, as they are called.

Recently, George Georgiev's Varna bike won the Deci-Mach prize for reaching 82 MPH on an almost-level, high altitude road. This is about double the regular bike record, despite the miles of acceleration needed to quadruple the momentum. In a practical vehicle, you can get up to 50% more speed than a bike, and, on a grid road system, that will put over twice as many destinations within range for a given riding time. With three wheel tracks, higher speed, reduced visibility, and no standing on the pedals, a suspension system becomes very desirable, which again increases comfort and speed while saving the tires from damage. The enclosure reduces the cooling air flow over your body, but sitting in the shade reduces the need for cooling.

If you can keep your head cool, you can feel OK even if your body is dripping sweat, so most velomobiles leave your head exposed. A full enclosure reduces vision, even when equipped with windshield wipers and demisters, which become essential for the commuter. A bit of rain on the face and helmet don't seem to matter when you are getting damp from perspiration. Velomobiles really come into their own in winter, when you can ride through snow, comfortable in shirtsleeves.

Using a bike or velomobile regularly is an excellent way to maintain fitness while actually saving time. Bike riders usually win races to downtown destinations against cars and public transit; there's a reason couriers use them. Velomobiles are not as good for filtering through traffic as bikes, but they still let you wipe out the day's stress with a workout on the way home. Some people ride gently to work, or use an electric booster in order to arrive looking cool and fresh. Despite all this talk about sweat, once you are used to riding, you don't notice the effort as much you miss it if you don't go.

In rolling country, a streamlined velomobile does much better than a bicycle, maintaining momentum from the downhills most of the way up the next hill. However, in stop and start traffic their coasting ability and momentum is a liability, since the rider alternates between short sprints and long rests, without much airflow at times. With an electric booster controlled by a pendulum, everything gets better. The controller can be set to make the whole trike and rider feel almost weightless. Accelerating or climbing hills, it takes only a little extra effort to get up to your regular cruising speed, but on the level, it leaves your top speed the same, and starts regenerative braking as soon as you coast or head downhill. That keeps the descents safe - otherwise, they can easily get up to speeds that beg for more crash protection. The booster and battery pack are still light enough that you can still pedal home with a dead battery to replace the power lost to inefficiency. They also let the designer relax and save money on super-light construction, so the price comes out about the same.

Some people will prefer motoring to pedaling, and there again, the velomobile shines as a good starting point. Instead of cutting down from a vehicle designed for over a hundred horsepower, and trying to get to 100 MPG, we can start with one designed to get along on a tenth to a quarter of a horsepower, and get 500 MPG easily. The record for those types is over 10,000 MPG at 15 MPH, which translates to about 750 MPG at 60 MPH.

Over the last three decades, recumbent bicycles have become popular enough that most people have seen a few in use. Recumbent trikes are proportionately more popular than upright trikes, but are still very rare. A few manufacturers have tried adding streamlined bodies, or "fairings" to production trike chassis, but the lack of integrated planning shows. The Netherlands have become the hotbed of development for real velomobiles, being a particularly suitable market. The most advanced company, Quest, is now establishing a second small factory in Toronto, Canada. Most of the companies have a waiting list, except the one that tried to introduce mass production methods. There is still a lot of work to do before prices look reasonable, but if you use a velomobile to replace a car, it is still an economic proposition. It will pretty well cover those "I'd use my bike today, but . . ." excuses.

Views :3849


Intended for the International Bicycle Design Competition a half dozen shape-shifting bicycle meet the demands of close-in urban commuting. Computer illustration is of Everglide bike.

The plan is to have 1,200 LEVs available for rent at 250 stations in a first phase, and 10 times that many in a second phase. Pictured is Ultra Motors A2B electric bicycle.

At $3,400, the Gucci cycle is one of the eight exclusive accessories designed especially for the forthcoming Beijing Olympics.


blog comments powered by Disqus