Worb5 Special Lip Crankshafts offer increased performance when used in combination with membrane motors. Aerodynamic design, coupled with finest craftmanship, balanced and polished, this baby delivers an optimal air-gas mixture flow through the crankshaft and under the pistons. Minimal loss of crankcase compression, compared to loss ocurred using a full circle crankshaft. A new standard or long stroke crankshaft is the base of this conversion. Dr. Worbel is quoted as saying "Hmm, ok....... So you want to know how much power reaches your back tires? Take a 210 Polini or a Malossi, an english exhaust, 30er carburetor, and, of course, a reed valve. What happens here with special lip crankshafts shows up in the entire speed range. Your motor simply pours out "clean" power. Two more horsepower guaranteed! Seeing is believing, as shown on the shafts got barely over 20 HP, while 2 scooters with a lip crankshaft (and no tricks!!!) got 22,5 HP and more." What more can we say!