WHY
Shoulder rings are used to balance the axial play between the gangrels. Distancing the gear wheels is essential for a cleanly working gearshift. The tighter the game is selected, the less the gears can slip sideways. The gear change is more precise as the shift cross now engages right in the middle of the gear and does not push it away first. It is therefore worthwhile to precisely measure the transmission.

HOW MUCH
The game specified by Piaggio is 0.15-0.40mm. It is determined between the gait and the shoulder ring using a feeler gauge.

DIFFERENCES
The shoulder rings are originally available in two versions:

• Thick (2.0-2.5 mm original with only one nose) suitable for Vespa Largeframe from 1952-1984
• Thin (0.9-1.4 mm with four noses) suitable for Vespa Smallframe and Vespa Largeframe from 1984 (main shaft with two shoulder rings/sea rings)

OLDIES
The thick version of the shoulder rings for Largeframe Vespas before 1984 has not been available from Piaggio for some time now. Thanks to bgm PRO, the right shoulder rings in the range of 2 mm to 2.50 mm are now finally available again for these transmissions.
As a departure from the original, they have 4 lugs for locking, as with the more stable Vespa PX Lusso variant. It is therefore no longer possible to cut off the individual nose in the new design.

Tip: The exact play between the gear wheels is only possible with a feeler gauge (see accessories). Don't forget a new BGM Pro switch and transmission oil.

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 demanding drivers. Thanks to first-class workmanship and a wide range of products, BGM offers ideal solutions for performance, everyday use and individuality.