Selector Box KR AUTOMATION PX "old", CNC reinforced

A strengthened gear selector ratchet enabling a perfectly functional Vespa largeframe gearbox.

The selector ratchet ensures the cruciform is held in the correct position within the drive shaft. This means that the cruciform and gear cog selected need to be exactly aligned. If the selector ratchet does not function ideally, this can lead to potential gearbox damage through mis-selection.

• Precise operation.
• Solid gear positioning.
• Longer service life.

Regretfully there are a whole row of parts that can cause unwanted mechanical-play between the drive shaft and selector ratchet. This, of course, also includes the selector ratchet itself. Additionally its mechanism is not very stable or precisely manufactured and is often exposed to strong wear. This makes it essential that this part of the transmission be in perfect working order.

Two firms have decided to provide a viable solution to the lack of quality replacements. Both the teams at ROLLER SCHUPFEN and KR-AUTOMATION have improved selector ratchets available, where the mechanism is more stable, precise and enduring. Two products 'Made in Germany' that take a different approach to the job in hand:

'Schaltissimo', produced by ROLLER-SCHUPFEN

The Schaltissimo is a selector ratchet that has been completely disassembled, reworked, strengthened and reassembled. Amongst other modifications, a sleeve has been welded into the selector arm for reinforcement. The connection between the cruciform and the selector arm rod are thicker and also reinforced. The rod is laid within a sleeve and sealed with an ´O` ring. A stronger spring is also used.

KR-AUTOMATION

The engineers at KR-AUTOMATION chose another route. The selector rod and cruciform are CNC machined and then tempered. The arm is positively fitted to the selector rod. The selector ratchet disc has been reconceived and rewards with a more noticeable gear selection position, with out the need for a stronger spring.

Conclusion: If you ride mainly in an urban environment and change gear relatively often, you will greatly appreciate the extra user-friendliness and reliability of these selector ratchet mechanisms!

The best set up - our SIP-TIP:

• A high-end selector cruciform. The premier league is represented by the SIP-BFA version.
• The SIP Performance control cables contribute to additional precision and easy operation.
• The SIP 'Short-shifter' gear selector types provide minimal selection movement.