US Olympians' high-tech bikes

The best racing bicycles in the world are not for sale. But when the US Olympic cycling team springs into action Sunday, the experts are predicting that their new ''funny bikes'' will bring in plenty of gold - in events where Americans have won no Olympic medals at all for 72 years.

The 18 hand-built Olympic bicycles they will be using are extremely light: The 14-pound team time-trial bike (at least 31/2 pounds lighter than the competition) is half the weight of a standard off-the-shelf machine. Not surprisingly, it's also expensive: Where the standard bike might cost $160, these are valued at about $25,000 apiece.

Developed behind the electronically sealed doors of the Huffy Corporation's Technical Development Center in Dayton, Ohio, these machines push the design restrictions of the Union Cycliste Internationale (UCI, the governing body for bicycle racing) to the very limit:

* The pursuit and team time-trial bikes will roll to the starting line with no spokes on the wheels. Instead, each wheel will be supported - and streamlined - by a graphite-Kevlar composite disk. The team's lawyers hope to persuade balky officials that this innovation is legal because the disk amounts to a big ''single spoke.'' Should the spokeless wheels be banned, the US team is standing by with wheels built using a flat-spoke design smuggled out of East Germany.

* Bikes for the team pursuit and team time trial will have small wheels - allowing team members to ride closer behind each other, permitting better slipstreaming.

* The almost blade-like tubing - 30 percent narrower, but deeper front to back than the tear-drop-shaped tubing used on other racing bikes - is composed of a secret alloy originally made for the space shuttle. Raleigh engineers, scooping up the last 700-pound surplus of the expensive alloy, were able to build a bike with a front profile some 20 percent narrower than usual.

''It's the fastest bike I've ever ridden,'' says US team member Steve Hegg, who is confident he can set a world record in the individual pursuit event.

This year's innovations, however, extend beyond the bikes themselves. Riders in the pursuit event, for example, will wear aerodynamic helmets - equipped (if officials allow it) with radio receivers for the instructions that coaches used to have to shout over the din.

Even their clothing will be aerodynamically designed. But instead of the slick-all-over rubberized suits that armchair theorists have imagined, the clothing (taking a cue from the bumblebee) will be a bit fuzzy in places. The reason: At speeds of less than 50 m.p.h., ''a certain roughness improves the aerodynamics,'' says Dave Allen, head of Huffy's Technical Development Center.

Aerodynamics has been a hot item in the bicycle industry for about four years , but this year's American-built machines take it a step further. According to the makers, both the clothing and bikes are the first to be made using low-speed (35 to 42 m.p.h.) aerodynamic testing. ''High-speed aerodynamics really doesn't apply,'' Mr. Allen says.

He says earlier aerodynamic tubing and bike parts from Europe and Japan were developed in high-speed wind tunnels. The US team's equipment, however, was developed using a unique, low-speed wind tunnel at the University of Texas at Austin. ''No one else we know of has the capability to do low-speed aerodynamic testing,'' Allen claims.

Aerodynamics is a tricky proposition in bicycle racing. At 25 m.p.h., 90 percent of a cyclist's effort goes into overcoming wind resistance. This proportion rises as you go faster. But the UCI has long had strict rules designed to equalize equipment - so that races are a test of the riders, not of the equipment. Under today's rules, bits of a bicycle can have the rough edges smoothed off. But nothing can be included whose primary purpose is to reduce wind drag, such as fairings or windshields.

The result, according to Chester Kyle, has been to dwarf the development of bicycle technology. Mr. Kyle, a southern California engineer, founded the International Human Powered Vehicle Association in 1975 to run pedal-powered races unhindered by the UCI rules. When the new machines, shaped like long jellybeans, began setting records in the 55-to-60-m.p.h. range, aerodynamics once again came to the attention of bike designers.

So three years ago the United States Cycling Federation (USCF) turned to a team of experts on human-powered vehicles who included Dr. Kyle and Dr. Paul MacCready, builder of record-setting human-powered aircraft.

Then, 18 months ago, the Huffy Corporation got involved. Huffy, a builder of bikes sold mostly in department stores and discount houses, claims to be the largest bicycle manufacturer in the world. When its market research told the company the Huffy name could never gain a foothold in the higher-priced bicycle market, Huffy acquired American rights to use the Raleigh trademark, a long-established and respected English name.

In 1982, however, Huffy's Raleigh subsidiary lost a bid to become the ''official manufacturer of bicycles for the 1984 Olympics'' - a distinction similar to being named the official snack food for the games. The winning bidder - the rival Murray Ohio Manufacturing Company - soon had reason to start looking over its shoulder: Huffy struck a deal with the USCF to make Raleigh the official bike of the US National Cycling Team, and the public-relations war was on.

Huffy's $600,000-to-$1 million agreement with the USCF - corporate officers are intentionally vague about the exact amount - included taking over the USCF high-tech bike program, as well as financing travel, coaching, and other expenses of the US national team.

The program is part of an experimental ''Elite Athlete Project,'' started by the US Olympic Committee in 1982. Under the program, cycling and six other sports will be given the benefit of concentrated scientific research designed to improve performance - and to offset the benefits of government support that athletes enjoy in other nations. According to Ed Burke, director of the USCF's Elite Athlete Project, this team approach ''has made dramatic strides in closing a communications gap that has divided US sports scientists from coaches and athletes.

But when Huffy became a sponsor of the Elite Athlete Project, it had just 18 months to come up with the advanced bicycles. At the time, the Americans were several years behind Europe and Japan in building such machines. So Huffy hired Michael Melton, a custom-bike frame builder who had learned the rudiments of his craft moonlighting at a frame factory when he was stationed with the Navy in Japan, to build prototypes.

In the time since, the bicycles have gone through five distinct stages of evolution. The first ones were taken to the Pan American Games in 1983, where they surprised US cyclists and others as well: Americans took five gold medals, set new records, and came away with many individual best times.

''Those first designs were Neanderthal compared with the fifth-generation bikes that will be used in the Olympics,'' says Phyllis McCullough, a Raleigh spokeswoman. They were good enough, however, to excite the interest of others. A Cuban coach approached US coach Edward Borysewicz with an offer of $50,000 for one bike. The Polish national team sought to purchase a set of them. More recently, Mr. Melton has turned down a blank-check offer from Brazil to buy a dozen bikes.

With athletes sponsored by Murray, Raleigh, and other companies all on the US team and training on Raleigh bikes, it has proved impossible for Huffy to keep the ''funny bikes'' under wraps. ''The other week,'' recalls Huffy's Mr. Allen, ''we even caught a Murray-sponsored member of the US team ... measuring our wheels.''