Clutch incl. primary gear -SC, Wideframe, type Cosa2/FL- primary gear BGM Pro 63 tooth (straight)- Vespa 125, VN1T (60001-), VN2T, Vespa 150 VL1T, VL2T, VL3T, VB1T, ACMA 150 GL (1956-1958) – 25/63 tooth (2.52)

Complete sport clutch incl. primary wheel and reinforced repair kit for Vespa Wideframe models from 1954 onwards (VN1T (60001-), VN2T, VL1T, VL2T, VL3T, VB1T, ACMA (56-58)

The SC coupling is based on the mature and proven BGM Superstrong coupling for the PX models. It offers a modern and stable clutch technology for the 125-150cc Vespa Wideframe engines from 1954 onwards.

These already have a clutch cover, whose three fixing screws are outside the outer radius of the cover. This corresponds to the modern standard of the Vespa PX models. The older models before 1954 (e.g. VM1T/VM2T) still have internal bolts. These do not fit large clutch types like the one shown here with Øa=115mm. We offer here our own coupling type.

The big advantages of converting to the SC coupling are

• Very easy to pull
• Separates very cleanly
• Fast and precise gear changes
• Very stable and perfect for tuned engines
• Including spacer, gasket, washer, coupling nut, crescent and O-ring

The SC coupling replaces the conventional type of coupling, the Vespa from about 1954, and can
therefore be used in Vespa 125, VN1T (60001-), VN2T, Vespa 150 VL1T, VL2T, VL3T, VB1T, ACMA 150 GL (1956-1958).

MODIFICATIONS
Since the clutch has a larger diameter, minor modifications to the engine housing and clutch cover are necessary for assembly. This is done by removing material from the drip nose (for the transmission oil) in the engine housing and clutch cover positioned at 12 o’clock. On the flat surface at the 9 o’clock position, also ensure sufficient clearance, if necessary remove some material here as well. A spacer with seal is included in the set. These provide a larger distance between the clutch cover and the clutch to compensate for the greater overall height of the clutch.

TRANSMISSION
S Stronger motors require longer reduction ratios for the optimal use of their potential, otherwise the motor literally turns into nothing. The Vespa wideframe models all have a primary reduction of 22/67 (clutch primary gear).

The easiest way to get a better clutch and at the same time a longer transmission ratio is to use our clutch SC6723L. This uses a clutch pinion with one tooth more (23Z instead of 22Z) and can be used with the original primary gear (67Z). This alone increases the top speed by about 5km/h. Ideal for light tuning or production engines that are driven with a high-torque exhaust system.

Engine halves must be changed to variant’
Engines that have been significantly increased in performance (e.g. tuning cylinders, exhaust and carburettor) require a longer than the plug&play possible 23/67Z transmission ratio. Therefore not only the clutch pinion but also the large primary wheel in the engine is changed. For this it is necessary to disassemble the engine completely. A work which is worthwhile however and does not make more work in the course of a revision.

The Wideframe engines from about 1954 on have the more modern design of the primary drive, easily recognizable by the cover plates, which are fixed by 6 rivets. These primary drives can be equipped with primary wheels from bgm Pro as well as Bollag Motos and reinforced bgm primary repair sets.

Oblique or straight?
The bgm Pro primary wheels for the Wideframe are always straight toothed. They offer the advantage that they do not exert any axial (lateral) forces on the crankshaft and the auxiliary shaft. This effectively eliminates the risk of premature wear of the crankshaft bearing seats due to moving bearings. The straight toothed bgm Pro gear parts are manufactured with such high precision that they run just as quietly as the original helical gears.

In general, the bgm Pro primary gears (62Z/63Z) can be used to achieve longer ratios than the helical gears from Bollag Motos (64Z /65Z). As long as one type of gearing is kept (helical or straight), all offered pinion/primary gear combinations are compatible with each other (a 23Z clutch can be used on the 62Z or 63Z primary gear, or a clutch can be converted from 22Z to 24Z without changing the primary gear).

Unlike most PX and Smallframe models, the Wideframe engines do not simply use the same secondary transmission, but depending on the engine type, there are different 3-speed and 4-speed transmissions which always consist of the same primary reduction of 22 teeth on the clutch pinion and 67 teeth on the primary wheel.

With many engine types a conversion from a 3-speed gearbox to a 4-speed gearbox is possible. Therefore it is necessary to select the new primary drive to match the transmission used. We have based our selection on empirical values from everyday life. A Rally 200 serves as a reference, which produces approx. 9-10hp on the road and runs approx. 100km/h at 6,000 rpm.
The following primary reduction ratios are based on these driving performances, because the engines of the Wideframe put similar power and torque values to the rear wheel due to the power increase.

With the original tyre size (3.50 x 8″) of the respective models, the following gradations result for performance enhanced vehicles:

VL, VB (3-speed, 14-56, 20-49, 27-42)

• Clutch pinion 22 teeth(straight toothed)
• Primary gear 64 teeth(straight toothed)

(optionally also 23 / 65 helical gears)

GS 150 VS1-5 At present, no changes to the primary are possible here due to the clutch design.

4-speed ACMA GL and replica (Pinasco) (13-57, 18-52, 23-47, 27.43)

• Clutch pinion 23 teeth (straight toothed)
• Primary gear 63 teeth(straight toothed)

(optionally also 24 / 65 helical toothing)

4-speed BGM Sport on 3.50-8″ (12-57, 13-42, 16-38, 19-35)

• Clutch pinion 25 teeth (straight toothed)
• Primary gear 62 teeth (straight toothed)

FITS :

• Vespa (A.C.M.A.) Vespa GL 150 (1958)
• Vespa (Douglas) Model 102L2 (VB1)
• Vespa (Messerschmitt) Vespa 150 T/1 (type 42, VL2T)
• Vespa (Piaggio) Vespa 150 (VB1T)
• Vespa (Piaggio) Vespa 150 (VL1T)
• Vespa (Piaggio) Vespa 150 (VL2T)
• Vespa (Piaggio) Vespa 125 (VN1T)
• Vespa (Piaggio) Vespa 125 (VN2T)