The UC Berkeley Human Powered Vehicle Team was founded in 1986, during which year no vehicle was constructed. In 1987 the first vehicle was created, a carbon fiber and aluminum tricycle. The first successful vehicle was built by the team in 1988 and '89, named Concept Z. It was a bicycle consisting of a carbon fiber and aluminum frame, with a twenty inch front wheel and 27 inch rear. The fairing was created from a Kevlar/epoxy composite. In the spring of 1990 the completed Concept Z raced at the American Society of Mechanical Engineers (ASME) national collegiate competition, where it placed first in the design competition, first in the sprint, and first overall. The following year a new fairing was constructed for the same bicycle, and the team again placed first in the sprint and overall competitions. With proven success in the national collegiate competition, the team decided to enter the International Human Powered Speed Challenge (IHPSC) in August, 1991. Competing against the top HPV racers in the world, the team placed third overall, capturing its first world record in the 1/4 mile drag.
In the fall of 1991, work began on an improved version of Concept Z, named Z' (pronounced Zee Prime). The vehicle's front wheel was downsized to a 17 inch (in order to save space), and a new, lighter, stiffer frame was built. Also, an aerodynamically optimized fairing was constructed from carbon fiber, which is stiffer than Kevlar. At the 1992 ASME competition, Z' placed the team first in the design, sprint, and overall competitions for the third year in a row. At the 1992 IHPSC, the team placed second in the world overall, and broke its previous record in the 1/4 mile drag, racing head to head against the top speed world record holder of the time. Sporting a newly designed and optimized fairing in 1993, Z' again captured first in the sprint at the national collegiate competition, this time for the fifth year in a row. In the fall of 1993, Z' raced at the first ever Colorado Speed Challenge, where a Berkeley Ph.D. student set the collegiate top speed record, racing against former world record holders and international champions. Z' is still the only collegiate vehicle to break sixty miles per hour. At the 1994 ASME nationals, Cal HPV extended its reign in the top speed competition, becoming the only team to win the top speed title for more than half of the years that the competition has been in existence! After dominating the 1994 IHPSC (winning four of five events), the team decided to set its sights on building a two rider vehicle.
The tandem bike turned into the longest project in our history, so far we have been working on it for five years. In 1997-8 A prototype built from a chrome-moly space frame was raced at ASME and did well. In 1998 a fairing was made for it and It took 1st in the ASME tandem Sprint and Road Race. Then in 1999 the team took on two huge projects: making a carbon fiber monocoque verson of the tandem, and hosting the 1999 ASME Race, entitled "Race the Bay." The tandem would later be named, "Bearacuda," after the cal bears and the killer fish. And it was a killer, winning The ASME sprint and Road Races with ease that year at Treasure Island. After significant improvements, especially on the seats and front drive train, the Bearacuda swept the 2000 ASME Tandem division, winning in every catagory.
The team's next move was to attempt a tandem world record. They decided on the low altitude record, which was 62.8 mph. The event took us to California Valley, and a 3.8 mile stretch of asphalt. With the help of the IHPVA, the people of calval, and our great riders, Michelle Khine, Melodie Metzger, Mat Glaser, and Lance Doherty, we turned two weekends into an exciting attempt. Although we maxed out at about 58.4 Mph, we did pick up THREE other world records!
What project will we tackle next? Who knows?
5 Time Collegiate National Champions Overall, 2000, 1999, 1992, 1991, 1990
8 Time Collegiate National Top Speed Champions, 2000, 1999, 1998, 1994, 1993, 1992, 1991, 1990, 1989Gold Medals in 1/4 mile drag, 25 mile road race, 1 hour time trial, and women's 200m sprint at Internation Human Powered Speed Challenge, August, 1994
When CalHPV designed and built their last bike, they thought that they had refined it as much as possible. So they called it Concept Z, because it was supposed to be the last in the current series (recumbent, rear wheel, single rider). However, after a lot of use, and several competitions, the team noticed several small things that could be improved upon even though the original concept was sound.
Out of this refinement came Z' (the derivative of Concept Z). It was designed by Kevan Chu and Eric Anderssen, with fairing design headed by Adrian Adamson, and built by the team over the course of the 91-92 season. Z' is considered by us to be about as far as we could take this type of design
Pics: Concept Z Frame Next To Z' Frame
Z' is a single rider recumbent bike with a wheelbase of 48" and weighing 21 pounds (frame only). The frame is a monocoque design built from carbon fiber and machined aluminum inserts.
Components on the bike include Shimano shifters and derailures, Hugi hubs, Murgia brakes, a Spengle Composite Rear Wheel, a Moulton 17" Front Wheel, and Magic Motorcycle Cranks.
The fairing is a highly optimized airfoil constructed from vacuum-formed composite. The current fairing is actually a completely different design from Z's original fairing (now on display on the 3rd floor of Etcheverry Hall). The new design was optimized in Rasna's Mechanica Software to test for skin deflections due to aerodynamic disturbances.
The bike frame is made out of about 1.6 pounds of carbon fiber, and another 1.4 pounds in aluminum inserts. It was built with center foam core contruction (the foam was later removed). The fairing is made from a 20 thousandths thick (single) layer of carbon fiber and a backing layer of Kevlar (to protect the rider). Including the Lexan windsheild and blue foam ribs the fairing weighs approximately 16 pounds.
