The now possible power and torque values of the so-called small-frame motors have increased considerably in recent years and appear to be growing steadily. Power and torque values of well over 35PS / 30Nm are becoming increasingly common. Of course, other components are also subject to much higher loads as a result.
An important and highly stressed link between the crankshaft and the gearbox is the clutch and the primary drive. The weakest link in this chain are the springs of the shock absorber.

Through them the whole torque is transferred to the rear wheel. They ensure a uniform transmission of power to the transmission and dampen the uneven running of the crank drive between the dead centres. Heavy crankshafts, increasingly lighter flywheel masses and heavy load changes, not only in racing, shorten the hard life of the original springs.

Fitting the BGM PRO primary repair kits BGM0190, BGM0192, MMW Hartz4/5 and of course the original primary repair kits, we have added reinforced springs to our program for you.

Compared to a Piaggio spring, the BGM spring offers more spring force and by the selection of the spring wire more working travel.

Due to the larger possible working travel and the increased spring rate, the gearbox and primary drive are protected from tooth breaking load peaks even under harsher operating conditions.

The advantages of the BGM PRO spring (BGM0190F) for primary Vespa Smallframe:

• increased working travel
• increased spring force
• original installation dimension
• material selection and processing for increased durability
• suitable in many primary drives

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