RECORD-BREAKINGRUNSTUDENTSECLIPSE 27-YEAR-OLD SPEEDRECORD AT THE WORLD HUMAN-POWEREDSPEED CHALLENGE12 | ME.CALPOLY.EDUThe human-powered vehicle teamtakes “Ambition,” the human-poweredvehicle to prepare for their big race atBattle Mountian, NV.
On its last possible run, ahuman-powered vehicle(HPV) created by a teamof Cal Poly engineeringstudents broke theAmerican collegiate speed record,setting a mark that hadn’t beenbested in nearly three decades.The new record, 63.68 mph, was setduring the 20th annual World Human-Powered Speed Challenge in BattleMountain, Nevada, held Sept. 8-13.The previous record was 61.29 mph,set by a team from UC Berkeley inSeptember 1992.A HPV is any vehicle powered bymuscular strength. The most commonHPV is a bicycle. Cal Poly’s HPV,named Ambition, competed againstother enclosed recumbent bicyclesthat were designed, built and riddenby students. Professional teams alsocompeted in separate categories.Ambition was tailored to its driver,Josh Gieschen, a biochemistry majorfrom Davis, California.Battle Mountain is an optimumlocation for the event because of itsthin air at 4,619 feet, which reducesaerodynamic drag. Riders travel downa 5-mile stretch outside the town onState Route 305, on what organizersboast is one of the straightest, flattestand smoothest roads in the world,reaching their maximum velocitybefore being timed over a 200-meterdistance.The object of the event is to makethe most aerodynamically efficientvehicles possible. Meanwhile, thetechnologies used for the HPVscan apply directly to all forms oftransportation.Ambition is a front-wheel-drivebike covered with a bullet-shapedshell, made out of carbon fiber andKevlar, to maximize aerodynamicperformance. Members of the CalPoly team split into subgroupsspecializing in different areas, such asthe bike frame, shell and drive train.Mechanical engineering seniors DerekFromm of Seattle and Michael Juri ofFremont, California, developed thedrive system.While Cal Poly has had a humanpoweredvehicle team since 1978,this was the first time it attempted tobreak the record. After working onthe vehicle for a year, the team hadto make multiple significant changesin the days leading up to the race,adding a windshield and fixing a chainthat repeatedly fell off.“We had issues, but we knew we hadtime to fix them,” said Kyra Schmidt,the manufacturing lead.The day before leaving for Nevada,though, they had a promising test run,Schmidt said, giving them confidence.Still, there would be other factors —some out of their control. To qualifyfor a record, the wind can’t exceed3.7 mph. Some years, it’s simply toowindy for anyone to qualify, Frommsaid.During the week, Ambition actuallysurpassed the record on Thursday,reaching 66.43 mph. But the windspeed disqualified it as a recordbreakingrun.As the final day approached, windwas forecast to exceed 3.7 mph in theevening. But the Cal Poly team had awindow of opportunity earlier in theday.“It was literally our last chance,”Fromm said.Gieschen got off to a good start.The so-called “motor,” who made 10runs over the week — often racingtwice a day — was tired and battlinga cold. But his speed continued toincrease until finally exceeding the27-year record with “legal wind.”And when it was over, Gieschendramatically crashed at around 50mph, the vehicle rolling over roughlythree times.Fortunately, Fromm said, Ambitionwas well built, and safety measuresworked.“Not a single thing broke on the bike,”he said.Gieschen walked away with just acouple of small bruises.“We are all super proud of everythingJosh and the team accomplished,”said Schmidt, a mechanicalengineering senior from Irvine,California.Next year, the team is looking at 70mph, she said — and, once again,she’s confident they can do it.“We are excited to continueimproving and come back even betternext year — but first, we can all take awell-deserved break.”Visit hpv.calpoly.edu for moreinformation about HumanPowered Vehicle.MECHANICAL ENGINEERING WINTER/SPRING 2020 | 13
Change language