Competition Update
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Competition
Results
New Design: A new HPV will be built this year. Some of the new ideas being considered are two person designs with side by side riders. This will provide a more compact design. By shortening the wheelbase and sitting on top of the frame, instead of in the frame, drive train routing and gearing, handling, and durability will be improved, along with large reductions in weight. We will suffer from a large frontal area, but we will build a full fairing to minimize wind resistance. Check back to see concept models. Lessons Learned: Fairing: The fairing had too large of a frontal area. It probably reduced our performance instead of enhancing it. The fiberglass was expensive and hard to work with. Use a different material for next year. Drive Train: The 7 speed drive is not nearly enough gears for riding. Based on a cadence of 90 rpm, the effective speed range of the HPV was 10-25 mph, with gaps between gears of several mph. Optimum gears during the race were hard to find. The HPV is too hard to start out, yet it is not geared high enough to go over 25 without excessive, unsustainable, pedaling cadence. A regular chain drive with three chainrings will give us a range of 5-35 mph at the 90 rpm cadence. Using 5 chain loops cut efficiency. The new design needs to have 3 chainloops or less. Operator Position: Placing the crank location over a foot above hip height greatly cut blood flow to our legs. Compared to my road bike, my performance is much less. On flat ground, I can maintain a speed of 22-24 mph for 30+ minutes. During the race, the HPV averaged about 20 mph. Talking with riders at bike shops, a standard tandem bike can average 30 mph with moderately fit riders. With a full fairing, averaging 30 mph should not be hard to attain. Operator Controls: The steering has too large of tolerances, and excess play. The new design needs to minimize play and be more reliable. In addition, the tie rod needs to be more adjustable to optimize front end alignment. Frame: The frame was plenty strong to hold up the riders, but not strong to optimize performance. The front crank has little support, and flexes side to side as the rider pedals. This is a large loss of energy, as we heat the frame instead of move forward. The rear crank appears to be more rigid, yet if you push on the pedal hard while stationary, you can see the whole frame flexes sideways by one or two degrees, losing power in the process. Paint: The HPV must be painted before competition. Although we did get second in the design competition, we lost by only a few design points. Painting the frame could have made the difference. The frame was painted this fall after the competition to prevent further rust from developing, but it took longer than needed since the HPV had to be completely sanded and wire brushed to remove the accumulated rust. Spare Parts: Right before the design competition, the front tire had a flat. We had no spares, and we had to drive around for about 90 minutes to get the parts to fix it. We were unable to bring the HPV in to the design competition, and further hurt our chances of winning the design competition. This year, we must take common spare parts such as tubes, chain, and even brake and shift cables.  Jeff
Bartels and Michael Morse preparing for the sprint event.
 Jeff Bartels and Royal Elmore racing in the endurance competition. The weather could have been nicer.  The team, showing our overall place against teams from the single and multi rider categories.  Our three trophies. From left to right: Michael Morse, Jeff Fuerhelm, Jeff Bartels, Kyle Rehn, Royal Elmore, Gregg Swiss, and Woody Witherow ©2006 Jeff Bartels 9/09/2006 |