The BGM EVOLUTION crankshafts are very cleanly processed and convince with well thought-out details:

  • performance-optimized solid beam design
  • well balanced (special balancing only available on BGM PRO shafts)
  • 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 105mm as series). This provides a smoother running, less piston load and more leeway for adjusting the cylinder control angle.

FAZIT
Very nice stable and well balanced crankshaft which should be the basis for a healthy engine in every engine.

SPECIAL FEATURES LONG TRAVEL
The 55mm long stroke shaft makes it possible to get more displacement and longer cylinder control angles in an elegant way. The performance can be increased significantly again.

Please note that the additional stroke of 3mm has to be compensated with a corresponding compensation seal of 1.5mm at the cylinder head or cylinder base. The supplied spacer with 5mm only provides for the compensation of the longer connecting rod. The additional stroke of 3mm must therefore be additionally compensated by a 1.5mm gasket or a correspondingly machined cylinder head.

A foot gasket increases the control angle of the cylinder and thus provides the prerequisite for a sporty and speed-oriented power delivery. For full power, however, the exhaust angle must often be increased to compensate for the disproportionately increased overflow angle compared to the exhaust angle. For everyday engines it is usually recommended to compensate the stroke with a 1.5mm head gasket (or a corresponding cylinder head).

NOTE

The lifting of the cylinder at the cylinder base, which is necessary with long-stroke crankshafts, also shifts the mounting point of the exhaust. This may have to be modified accordingly in order to be able to mount it on the engine/cylinder again without tension.


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Anonym  12/11/2015

Hammer !!!! GoBabyGo !!!

Marc H. from Frechen 07/27/2025
Ball bearing
Dimensions
16x20x20mm
 
Piston pin
Diameter
16 mm
 
Crankshafts
Stroke
55 mm
Thread on alternator side
M12x1,25 Rechtsgewinde
Thread on drive side
M12x1,25 Rechtsgewinde
Crank web diameter
90 mm
Crankcase must be spindled
nein
Motor housing must be modified
ja
Rotary vane crankshaft
nein
Full cheek crankshaft
ja
Filling material for full cheek
Stahl
Material balancing weights
Aluminium
Diameter of variator stub
17 mm
Variomatic stub design
verzahnt
can be used with original variator
ja
Wide crank webs
46.4 mm
Bearing seat diameter on alternator side
25 mm
Bearing seat diameter on drive side
25 mm
Diameter of sealing ring seat on alternator side
25 mm
Diameter of sealing ring seat on drive side
25 mm
 
Connecting rod
Connecting rod length
110 mm
Connecting rod strength
5.5 mm
Connecting rod eye top diameter
20 mm
Lifting pin diameter
20 mm
Upper connecting rod eye lubrication hole
ja
Lower connecting rod eye lubrication hole
Schlitz
Connecting rod thrust washers
ja
 
General
EAN
4250366600659
 
OEM numbers (for comparison purposes only)
Scooter Center:
BGM038025
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