Advantage | Description |
---|---|
Universally applicable | For standard, tuning and long-stroke engines from 80-190 cc |
Extra long: 167 mm | 27 mm longer than standard - ideal for cylinder lifts |
Secure hold | Rolled thread like Piaggio original - but more robust thanks to CrMo steel |
Perfect fit | 6.9 mm shaft diameter - backlash-free for tuning cylinders |
Made in Germany | CrMo steel, hardened, high tensile strength |
The more stable, longer and better solution for all engine concepts from original to tuning.
Anyone who has ever fitted a tuning cylinder with a fat spacer plate will know the problem: the original 140 mm stud bolts are simply too short. The BGM PRO stud bolts in an extended version with 167 mm solve this problem cleanly - without compromise.
Whether PX125 with BGM177 and 60 mm long-stroke shaft or a smallframe with 105 mm connecting rod - these studs always fit. And the best thing is: Even if you don't want to tune (yet), you can install the bolts directly during an engine overhaul and are thus perfectly prepared for future conversions.
Made in Germany from high-strength CrMo steel - these stud bolts reliably hold their position even in thermally stressed setups with a long stroke, large control angles and thick spacer plates.
The screw-in side is provided with a Piaggio-typical oversize thread, which anchors itself particularly firmly in the engine housing and reliably transmits high peak forces.
Extra detail: A small shoulder is incorporated at the upper end of the thread - a practical threading aid for the nut when things get tight between the cooling fins.
The stud bolt has a laser-marked installation direction (TOP) - the arrow must point towards the cylinder head after installation.
This ensures that the side with the oversize thread sits in the engine block - for maximum stability even with highly loaded setups.
✔️ Aluminum cylinder: 13-15 Nm
✔️ Cast iron cylinder: 14-18 Nm
The 167 mm length allows the use of:
✅ Long-stroke crankshafts with spacer plates
✅ Cylinder lifts for control angle correction
✅ Tall tuning kits such as the Pinasco 206
✅ Also for series engines without spacers - thanks to sophisticated thread distribution
The shaft diameter is 6.9 mm - ideal for many racing cylinders where the cylinder stud bore has a deliberately narrow tolerance.
The lower thread is manufactured as a heavy-duty rolled (not cut!) thread with a slight oversize. Just as Piaggio did with its original stud bolts - but here with CrMo steel in BGM PRO quality.
Whether PX80, PX125, PK50 or ETS - with these studs you cover practically the entire spectrum from Smallframe 80-150 ccm to Largeframe 80-190 ccm. Also perfectly suitable for Vespa V50/PK50 conversions to long-stroke =>133cc (here the very short stud bolts, which only hold the cylinder at the base, are replaced by the long bolts of the 80-125cc engines). The new standard for all engines that can be built up today with a clear conscience.
Largeframe:
VNA1-2T, VNB1-6T
VBA1T, VBB1-2T
VGLA1T, VGLB1T, VLA1T
VNC1T, VLB1T, VBC1T
VNL2T (GT & GTR), VNL3T
VNX1T, VBX1T, VLX1T
V8X1T, VNX2T, VIX1T
PX80/125/150 E Lusso (EFL, Iris, Arcobaleno)
PX80/125/150 E Elestart
Smallframe:
VMA1T, VMA2T, VMB1T
V9B1T, VMX1T, VMX5T
VMS1T, VMX6T, VMX7T
Question | Answer |
---|---|
Does the stud also fit without spacer plates? | Yes - the thread distribution is selected so that standard cylinders can also be fitted without spacers without any problems. |
For which engine housings is the fixed seat thread intended? | The lower thread corresponds to the original Piaggio type - so it fits all Vespa smallframe and largeframe housings ex works. |
Why 6.9 mm shaft diameter? | Many modern tuning cylinders have close-tolerance bores for the stud bolts. 6.9 mm fits without play - even on CNC cylinders with precise guidance. |
Will the original M7 nuts fit? | Yes, of course. However, we recommend the M7 nut set from Naraku based on our own excellent experience. Thanks to their collar, washers are no longer required and the torque can be released in a much more defined manner. |