White Power Reinvents the Fork
White Power Reinvents the Fork
ROUNDUP
PEOPLE HAVE BEEN PROPHESYing the end of the telescopic fork in motorcycle suspension and chassis design for many years. but forks have remained the norm. Until, perhaps. now. White Power, of Holland, quietly has been working on a revolutionary new front-suspension design it calls the MonoArm.
The MonoArm is the result of a chat between WP designer Andre Verkuylen and Paul van Leeuwen, an engineering student, in 1987. After drawing-up their initial sketch on the back of a tavern napkin, the pair built a prototype MonoArm and fitted it to a test bike. It worked.
The latest development of the concept consists of a single, hollow, vertical steel strut pivoting on a large stem located in a 9.8-inch-long tube welded to the test bike's chassis in place of the original steering head. This has a steel plate bolted to the top of it which pivots and provides handlebar location. Within the MonoArm is a long suspension strut fixed to the inside of the hollow arm at the top, and, at the bottom, to a rectangular steel plate which slides up and down on strips of linear needle roller bearings.
The flat strips of bearings are housed in two bolted-together plates from which sprout the stub axle to which the front wheel is affixed.
After experimenting with fitting a single brake disc inboard of the wheel, the disc was moved to the outside of the wheel and mounted on an outrigger plate that slides quickly out of the way when you need to change a wheel.
“The MonoArm takes up where forks leave off,” Verkuylen claims, citing what he sees as the system’s benefits over forks: Improved stiffness: less unsprung weight; greatly improved braking performance with a single front disc; the ability to easily change a front wheel; no need for the lower triple clamp of conventional telescopic forks; additional space for fitting other equipment; and improved airflow to a radiator.
The proof of the pudding is always in the riding, so I set out on the current MonoArm prototype, a Cagiva Freccia 125. And I was impressed. Few tele-forked machines can offer the remarkable degree of road feel obtained with the MonoArm. You can. through the bars, actually feel what the tire is doing, feel how it follows the road surface, feel as it starts to chatter when you press too far.
White Power is on to something here. The MonoArm is innovative, unconventional and weird-looking, but it seems to work. Verkuylen plans to offer the MonoArm in a variety of sizes as a part of future aftermarket packages. And, he says, eventually, the MonoArm will replace White Power’s telescopic forks in roadracing.
Alan Cathcart
