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
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
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
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
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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