tech notes a chaparral racing ifs story

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Bobby wanted the arms as long as possible, so the ski-spindles were mounted on swing arms located back by the footrests, and the travel geometry followed two long radius rods mounted into the center of the front bulkhead. Steering rods lined up with the front radius rod, in order to minimize the bump steer. The shocks mounted to the front bulkhead and he also added a road race style sway bar. This was an absolutely unique suspension design never before seen on a snowmobile, and as it turns out 10 years ahead of its time before it finally went into production in 1981 on the Polaris TXL Indy.

Two versions were made for racing, a 440 and a 650, both triples. The engine work was farmed out to Harvey Stuska in Denver, famous for his Stuska water brake dyno’s. When the sleds first appeared they created quite a sensation, and many predicted that the design was too “flimsy” and would break during hard racing. In reality, nothing broke on the suspension, although they had plenty of problems with other parts like chains, belts and engines. When the finale lined up at the Eagle River World Championship in 1972, Larry Omans was in the field, so Bobby had accomplished his goal. When the start went, Larry blew away the field and led them all into the first turn. His success was short-lived, however, as the chain broke coming out of turn two and Mike Trapp passed him and took over the lead, winning his second World Championship for Yamaha. Although Larry did not finish the big race, earlier in the World Championship weekend, Mike Bettis of Green Bay had won the 440 Modified class in the cross country event, and later in the year Roger Padie on a Chaparral won the Alaskan “Midnight Sun” cross-country endurance race.

Chaparral was now firmly on everyone’s radar, although IFS suspensions were still only on the race-sleds. Bobby had more ideas; his next project was to mount racecar wings on the sleds. A sled with wings was made and tested, but was nixed by marketing as too radical and “out of the mainstream” for the general public. Bobby’s IFS design was elegant, effective and proven over time by being part of millions of sleds, improving and changing the way designers thought of controlled long travel suspensions.

In the end, Chaparral’s George Walker threw Bobby his party out at Walkers ranch; and what a party it was! Bobby had the racing department build a 21-foot barbeque grill for the meat and two large bowls for boiling the fresh shrimp they brought in from Louisiana, along with the lobster flown in from Maine.

Employees from the race shop, their families and kids, all the management, important racers, crew and sponsors were invited. Bobby also made sure that everyone in the press that had featured their effort was invited, including paid airfare, hotel and rental cars. It was a real “Bobby Unser” party, and when George Walker finally got the bill, he said “It would have been cheaper to PAY HIM!” But no one could deny that the PR value was great, and all the hard work was rewarded with a fun finale to a challenging season!
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