Cobra Friction Drive (CFD)
Did you ever wonder why a 50cc motocrosser has
beefier transmission gears than a typical 450F?
Why does a typical seven year-old break more
chains in a year than a seasoned pro? Do you
feel that you spend more time and money on items
such as clutch baskets and primary gears than
you think you should? Well, at Cobra we have
asked the same questions, and with our patent
pending Cobra Friction Drive (CFD), we’ve done
something about it!
The Cobra Friction Drive is one of the most
innovative pieces of technology to come around
in 50cc racing since Cobra first introduced the
modern 3-shoe clutch a decade ago. Its operating
principal is simple: The CFD adds some ‘give’ to
the driveline system. Unlike any other type of
motorcycle transmission, when a centrifugal
clutch (used on all 50cc motocrossers) is locked
up, the entire powertrain…everything from the
rear wheel to the crankshaft…is also locked. Now
imagine landing off a big jump with the throttle
pinned. The engine is spinning at close to
15,000rpm, and then SLAM, the rear wheel comes
to almost a dead stop as it hits the ground.
With very little give in the system, this
results in brutal wear and tear on many
components such as the crankshaft, clutch
basket, clutch shoes, transmission gears,
transmission bearings, chain, sprockets, and
rear wheel. It’s no coincidence that many of the
items that you replace and repair often are on
the aforementioned list.
So how does the CFD work? It’s very simple,
actually. The primary gear, instead of being one
solid part, has been replaced by a clutch that
is set to disengage at a pre-determined torque
level. This break-away torque is several times
the maximum engine torque (so it never slips
when the engine is driving it), however, when it
receives a high load in the other direction it
spins providing a cushioning effect on many
expensive engine and driveline components.
So what does this mean on and off the racetrack?
* More time riding and less time doing
maintenance!
* Durability improvements in all driveline
components.
* Longer clutch shoe life.
* Reduced weight and friction in the engine’s
final drive and more power to the ground.
* The freedom to aggressively throttle away from
heavy landings without having to worry about
things breaking.
* Overall reduced cost of ownership!
