MXA TEAM TESTED
CYCRA POWERFLOW KTM RADIATOR SHROUDS
WHAT IS IT?
A KTM radiator shroud that is designed to increase airflow through your bike’s radiators by
speeding up the flow of air. They are available for as low as $59.95 for Yamahas, KTMs and
WHATS IT COST?
$89.95 (2011-2012 KTMs).
CONTACT? www.cycraracing.com or (740) 929-0188.
WHAT STANDS OUT?
Here’s a list of things that stand out with the Cycra Powerflow radiator shrouds.
(1) Bernoulli. For all the high-tech components on a modern motocross bike, the least
sophisticated is the radiator shroud. That’s sad, because there are plenty of scientific studies
that would lead to a better radiator mouse trap. For example, modern, air cooled, piston
engine aircrafts are cooled through openings that are half the size of a motocross bike’s
radiator surface (with engines that are 20 times the displacement). The same holds true for
water cooled NASCAR and Formula 1 engines. How do they get away with such small openings
when motocross bikes have two large barn doors hanging out in the breeze and still overheat?
Their designers follow the lead of motocross engineering pioneer Daniel Bernoulli.
(2) Bernoulli’s principle. Daniel Bernoulli died 230 years ago, yet his theories dominate
every activity that involves the flow of air or water over or through a surface. Bernoulli’s
principle states that air velocity can be increased by decreasing the size of the duct it flows
through. And as the speed increases in the duct pressure decreases. In short, you can make
air flow faster if it enters a large opening and exits a small opening.
(3) APPLICATION. You can test Bernoulli’s principle for yourself. Take a garden hose and
put your thumb over the end, which will make the spigot smaller than the hose diameter. What
happens? The water picks up speed and sprays faster. The same thing could happen with a
motocross radiator shroud-if it were designed to take advantage of what automobile designers,
aircraft engineers and plumbers know.
(4) RADIATOR WINGS. If you think the best way to get air through a radiator is to put a big
scoop around it, you are wrong. Why? It’s not how fast it exits the back of the radiator that
counts. The amount of air coming through the radiator is dictated by the amount of air exiting
the radiator. Motocross designers haven’t fully explored the possibilities; they are still hanging
on to the barn door theory of cooling.
(5) POWERFLOW. Cycra’s Powerflow radiator wings have a unique scoop, hidden in the
inner surface of their radiator shroud, which utilizes Bernoulli’s principle to flow more air
through a radiator. None of the air in a small secondary Cycra scoop passes through a
radiator, but, instead, flows past it. However, as the scoops
dimensions decrease in size, the air in it increases in speed. Since the air in Cycra’s Bernoulli
inspired scoop is part of the overall airstream coming through the radiator, when it flows faster,
the rest of the air moves faster. More air equals better cooling
WHATS THE SQUAWK? No complaints. FIVE STARS
|CYCRA RACING is the premier motorcycle plastic manufacturer in the industry today. Providing Factory Motocross and Off-Road Teams like Honda, Yamaha, KTM, Suzuki and Kawasaki
with Innovative Products including Probend Handguards, Cycralite Fenders, Powerflow Body Kits, Vented Number Plates, Disc Covers, Motorcycle Stands, Mechanic's Rollcarts and more.
PHONE: 740-929-0188 FAX: 740-929-0197 ADDRESS: 171 O'Neill Dr., Hebron, OH 43025 WEB: WWW.CYCRA.COM
Cycra is a SV Plastics LLC. All Copyrights, Patents and Trademarks are Property of SV Plastics LLC. All Rights Reserved 2008.