The bgm EVOLUTION crankshafts are very cleanly made and impress with their well-thought-out details:

• performance-optimized full cheek design
• well balanced (special balancing that is only available with BGM PRO waves)
• stable connecting rod
• available with 52mm (std.) and 55mm stroke

The long-stroke version with 55mm stroke has a longer connecting rod (110mm instead of the 105mm series). This ensures smoother running, less piston load and more leeway to adjust the cylinder control angles.

CONCLUSION
Very nice sturdy and well-balanced crankshaft, which should be the basis for a very healthy structure in every engine.

SPECIAL FEATURES LONG STROKE
The 55mm long stroke shaft makes it possible to obtain more engine capacity and longer cylinder control angles in an elegant way. As a result, performance can be significantly increased once again.

Please note that the additional stroke of 3 mm must be compensated with a corresponding compensation seal of 1.5 mm on the cylinder head or cylinder base. The necessary 5 mm spacer (not included) only compensates for the longer connecting rod. The additional stroke of 3 mm must therefore be additionally compensated by a 1.5 mm seal or a correspondingly extended cylinder head.

A foot seal increases the control angle of the cylinder and thus provides the basis for sporty and speed-oriented performance. However, for full power, the outlet angle often has to be increased in order to compensate for the disproportionately increased overcurrent angle compared to the outlet angle. For everyday engines, it is usually recommended to adjust the stroke with a 1.5 mm head gasket (or a corresponding cylinder head).

NOTE
The necessary lifting of the cylinder at the base of long-stroke crankshafts also shifts the screw-on point of the exhaust. This may have to be modified accordingly so that it can be reassembled on the engine/cylinder without bracing.

About the manufacturer BGM

BGM is a leading brand for high-quality spare parts and accessories for scooters, motorcycles and classic Vespa models that stands for quality, precision and innovation. With an uncompromising “Made in Germany” philosophy, BGM develops durable products in collaboration with leading engineers and under strict quality controls. Whether restoring vintage cars or tuning modern scooters — BGM is the first choice for discerning drivers. Thanks to first-class workmanship and a wide range of products, BGM offers ideal solutions for performance, everyday use and individuality.