American Suspension bringing rocket science to motorcycling

Vince Costa is a former motorbike racer turned rocket test engineer, turned race bike suspension tuner. Who better to create motorcycle suspension systems as the head of American Suspension?

There may be a lot of people in the motorcycle industry who claim to understand the principle of suspension systems. Few, however, have credentials match those of Vince Costa, the founder of American Suspension, or the quality of his company’s products. “More custom motorcycles have been built this century with our forks than any other make,” is Vince’s proud boast.

Vince’s passion for engineering, and motorcycles in particular, began at an early age. As a teenager, he and a friend hung around the latter’s older brothers who were members of the Gypsy Jokers bike club, watching them building choppers.
Before long his friend was given a basket case Triumph chopper, and for helping fix it, Vince, then 14, became co-owner of a Triumph.

That experience led Vince to study engineering at college, up to the Master’s level, during which time he supported himself by worked in for an engineering firm. The shop specialized in automotive research and development work and its staff there included the crew chief of legendary motorcycle racer Mike Hailwood and engineers who had worked on the Le Mans 24 Hours race-winning Ford GT40s.

Exposed to such a rich racing heritage, Vince soon took up motorcycle racing. By the early ‘80s, he was being sponsored by Denis Manning of BUB Enterprises and competing in Super Bike races. By the time he retired from racing, he was nationally ranked rider.

Racing taught Vince a lot about suspension design and how real world testing can be combined with scientific theory. As he says: “In racing nothing matters except winning. It doesn’t matter how you figure something out, only if it works or not. The best engineers in racing have to understand things from a real world and theoretical standpoint.”

Denis not only sponsored Vince as a racer, says Vince, he also taught him some valuable skills as an engineer, including the “right way to structure tests.” It was something that proved useful after he finished racing. “Ultimately, I used what he taught me when I went to work for Lockheed Missiles, helping them with their rocket motors,” he says. “I’ve now carried that knowledge with me into the motorcycle industry.”

Employment with Lockheed came about in part as a result of the work he’d done while still in college, at the machine shop there he was involved in early experiments in predictive math modeling and computer simulation work on vehicle dynamics.

These were, at the time, new developments in vehicle design. The data logging equipment used then was so bulky that it would be carried in a separate truck, wired to the vehicle being tested.

Today, the same amount of data can be collected by a piece of equipment the size of a cigarette packet, but the value of testing remains as important.

Vince’s innate understanding of vehicle dynamics and his ability to test and analyze products, combined with his racing history led him to become a motorcycle suspension tuner, working with world class racers like Ben Bostrom. “I could communicate with racers because I’d ridden at race speeds on the same course as they were riding,” he says.

American Suspension was a development of his work as a race bike tuner and it began in his garage in 1997. Within two years he was approached with an offer to sell the business, by Primex Technologies, an aerospace company who knew of him and his reputation for high-quality work from his days at Lockheed. “The cold war was coming to an end and I guess they wanted to diversify,” Vince explains. “They made me a good enough offer for me to retire, while still a young man.”

American Suspension was run by a subsidiary of Primex Technologies, General Dynamics until 2001, at which point the parent company decided to re-focus its efforts. By 2002 Vince Costa had re-acquired American Suspension, albeit working out of his garage again.

Vince’s had put his time in retirement to good use designing suspension and brake application from a blank sheet of paper. The results are the product lines of today’s American Suspension and sales of them have seen the company grown to inhabit an 18,000sq ft facility and employ 30 staff.

One of the products is the Perimeter Valve, fitted to American Suspension’s inverted forks. Most inverted fork use an oil-filled cartridge to provide the damping. However, these can deform under extreme side loads produced when cornering hard, creating stiction in the fork.

Vince’s Perimeter Valve solves this problem. Instead of a cartridge, the entire fork leg is filled with oil and the valve controls the flow of it through the fork. When the wheel hits a bump and begins to move, the valve opens allowing oil to flow through. However, under heavy breaking, when the weight of the bike tries to compress the fork, the valve closes, stopping the front of the bike from diving.

Not all of Vince’s design work is done to improve ride quality; for instance, the Padlock brake caliper. “As a kid I thought the cool looking bikes were the ones without front brakes,” says Vince. “I was looking to recreate that clean look but include a caliper. So we made the caliper part of the lower leg, seen from the side it’s hard to see.”

The caliper is a simple twin-piston design, the reasoning being that this arrangement gives a broader sweep of the disc than a multi-piston design with differing sized pistons. Vince’s argument is that six-piston calipers, for instance, will only work use a narrow band of the rotor and thus have less swept area than the twin-piston layout.

To go with the Padlock caliper, American Suspension also produces the Phantom internal brake lines, which are an option on all of the company’s fork designs.

Not one to sit back and relax now the company is a success, Vince is still working on new designs, such as the new trailing link Springer, which moves the springs down on to the lower part of the fork. Hidden inside the springs are re-valved shocks originally developed for use on the rear of Super Twins World Championship race bikes. One of the many features of these forks is that all of the parts used are interchangeable with the company’s current conventional design of Springer, so when a customer decides to change the look of his/her bike, there’s no need to buy a completely new front end.

The as yet un-named new fork is currently being tested on American Suspension’s in-house test rig. The rig can simulate over 100,000 miles of riding in just a few days. The high speed testing cycle, which lasts 12 hours, has destroy regular 41mm fork bearing from competitors’ forks in less than an hour and head bearings in less than three, says Vince.

The test rig has been useful in other areas of development for American Suspension too. As a result of test work the company now has its fork tubes, which it buys in bulk quantities of 90,000lbs at a time, custom drawn to its own specification.

The benefit of having this done is that the grains in the steel are aligned with the direction of travel of the forks tubes as the suspension compresses and extends, creating fork legs less susceptible to bending under extremely hard use.

It is this application of science combined with real world experience that has given American Suspension an enviable reputation for quality. Vince is quite happy to use this knowledge to correct commonplace myths and misconceptions about suspension. “Some builders will call up and ask for triple trees with six or seven degrees of rake,” he says by way of example. “when what they don’t realize is that the rider might, without knowing it, have a preference for three degrees.

“ So I’ll try and get more details on the rider and do the math based on my experience tuning Super Bikes for racers. Despite all the science suspension is still something of a black art. I say that after having applied a huge amount of computer simulation and analysis time, particularly on motorcycles.

“ Ultimately, parts on a bike should be engineered to work together, says Vince, “and that’s what I do.”

The success of American Suspension certainly seems to bear him out.


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