"  Going Fast Is Also About Slowing Down Fast  "


Innovative Kawasaki Superbike Tech


I met Jan Greven at a Scandinavian Open Superbike race in Anderstorp, Sweden, and he was kind enough to let me take some photos of his very trick 163 horsepower Kawasaki Superbike. 

The bike is loaded with externally visible speed tricks, but the most interesting thing was a feature that Jan added, which links the rear brake to the front. It was invented by a man from Switzerland. 

Unlike the simple linked braking systems used on some streetbikes, this one features 2 rear brake calipers, one above the disc and a much smaller one below it. The main purpose is to transfer force through a system of levers to provide an ingenious advantage ...

The Advantage:
The upper caliper functions as a normal rear brake, that is to stop the wheel. But, the lower caliper isn't actually used for stopping force, (although it does do that too.)  Instead, a system of linkage "torque" arms transfers the braking torque from the lower caliper to the swingarm and frame. 

When the lower caliper grips the disc it naturally "wants" to rotate towards the rear of the bike. This torque force is transferred via the linkage rods, so it actually "pulls" down on the swingarm. This makes it harder for the rear tire to lift off the ground under hard braking ("stoppies" are cool to watch, but you don't want them while racing !) The result is increased braking stability as well as allowing much harder braking ! Since the rear brake is linked to the front, it works automatically. 
Wow !!!

Jan Greven
Fast rider and also a 
really good guy !!

Give his photo a
 " hit " !!

Inserts on the outer part of the ram air openings reduce the size of the openings to ... increase ram air velocity !!

This power secret is "invisible" on the dyno ... but not on the track !

Notice the welded aluminum gas tank and the tapered exhaust design. The Suter dry clutch is a beautiful piece of work. This is one trick race bike !

Wow !! 
Jan has the exhaust gasses pointing into the bike's aerodynamic wake !! This little known power secret is also invisible on the dyno, and it's one of the subjects of my Power News horsepower newsletter. 

Note the upper caliper and the smaller lower caliper. Behind the swingarm is the 1st linkage that connects the lower caliper's pulling force to a triangulated lever. The pivot for the lever is mounted in the middle of the swingarm, where the welded in section is.

From the top right of the triangulated lever, the second torque link leads to the frame. This prevents the lever from just rotating back. Instead, it forces the lever to transfer it's torque down onto the swingarm. Study the photo, and you'll see how this unique set-up allows Jan to brake deep into the corners !

Here you can see the lever and the upper linkage that leads up to the frame. Also notice that this disc is floating, and drilled radially in addition to the usual longitudinal drilling pattern !!

In front of the top triple clamp is an adjuster valve to change the proportion of front and rear brake hydraulic force.

Jan Greven's Website -- Greven's M/C Delar: