Motorcycle Hillclimbers - Upward Mobility

Where do old sportbikes go when they die? Some, after falling into the wrong hands and undergoing major deconstructive surgery, are aimed at large, defenseless piles of dirt in places such as the 88th Annual Miller Lite Great American Hillclimb Championship in Billings, Montana. Though recent studies suggest rigorous counseling and big-screen TV can prevent such tragedies, the motivation is all too predictable. Pro classes in the 89th launching of America's oldest motorcycle hillclimb-a.k.a. the Bentonite Nightmare-will contend for $40,000 in cash. Mark your calendar for July 27-29 and notify a responsible adult before you leave...just in case something goes wrong.

Less-brutal classes are limited to a 66-inch wheelbase, but there aren't many rules for an Open Exhibition Class hillclimber such as Jon Smith's Suzuki Hayabusa-powered atrocity. Wheelbase? Whatever works. No steel appendages allowed on the rear tire. Nitrous-oxide injection is permitted, but nitro methane is specifically verboten in the Western States Professional Hill Climb Series, though other sanctioning organizations aren't quite so picky.The 'Busa-based 'climber was the only motorcycle to touch the summit of this year's Widowmaker Hillclimb in Croydon, Utah, 45 miles from Smith's home in Woods Cross. His Suzuki covered the 1000-foot, 72-percent face in 41.2 seconds. That, sports fans, is quick.

Top-dog Unlimited Class power can and does come from just about any internal-combustion device you can bolt between two wheels. Two-stroke or four-stroke? Take your pick. We've seen everything from three-cylinder two-strokes pried out of spent snowmobiles to Desmo- quattro Ducatis and a Honda RC51 twin stuffed into a CR500 chassis. The displacement window opens at 701cc and closes when you run out of metal. The results are exceedingly potent. Though small-diameter headers suggest an emphasis on torque, Smith's transmogrified 'Busa makes upward of 230 horses in competition trim. A tiny radiator aft of the steering head keeps things cool.

Though there's no such thing as the average hillclimb chassis, most start as stock dirtbike frames. Not so here: Mr. Smith's one-off steel skeleton adapts a page from the GSX-R database with a pair of box-section spars for the heavy lifting. A tiny tank in between carries just enough fuel to complete the climb. Small-bore steel tubes cradle the front of the engine, and a spindly aluminum subframe carries the seat.

Serious hillclimbers use swingarm extensions that are welded on. Smith is beyond serious. Note the three axle-mounting slots machined in the Hayabusa's aluminum swingarm to vary wheelbase as needed. Rules specify one brake. Smith's is on the front wheel.