The NXS Quantum is/was a tiny, wireless, electronically controlled actuator that operates a conventional mechanical derailleur.

What makes it particularly unique is that it can mount directly onto the (usually rear) derailleur.

On the one hand this is a cunning move, eliminating most of the inner cable and all of the outer cable used by systems like the XShifter ELink, Archer D1x Trail and LTWOO Ae.

But on the other hand it seems, to my ill-informed eye, to leave the actuator in a precariously exposed position.

But NXS hedged their bets. They offered an option whereby the actuator could be attached to the frame and then to operate the rear derailleur using a short length of outer cable etc. etc.. This is similar to the earlier XShifter ELink. Based on no evidence, I suspect that this may be the option that most buyers ended up using.

The NXS Quantum was the brainchild of Paul Gallagher, who had previously created the XShifter. In an echo of the XShifter's slightly chaotic product pipeline, the NXS system may or may not have two generations:

• The first generation system was, possibly, launched in 2022. It was black, and possibly made of polycarbonate.
• By 2024 this initial system was comprehensibly 'out of stock' on the NXS web site.
• In early 2025 NXS launched a Kickstarter project to develop a second generation NXS system. This appeared to have CNC aluminium parts that could be anodised in fancy colours.
• At the time of writing (late 2025) the Kickstarter project has long ended, but it is unclear exactly when the new product will appear.

This particular, first generation, NXS Quantum was supplied as part of a 1X ATB kit. The kit includes a single pair of ‘Shifty’ control buttons suitable for straight bars, a ‘BlakBullet’ unit, to mount inside your handlebars, to send the commands from the buttons to the rear actuator, a, rather minimalist, battery charger and a, rather maximalist, bracket for mounting the Quantum to the bicycle frame.

• Derailleur brands: NXS
• Themes: Electric Avenue
• Country: Designed in the USA or possibly Thailand, manufactured in Thailand
• Date of introduction: 2022?
• Date of this example: unknown
• Model no.: Quantum: 90001, Shifty: 90005, BlakBullet: 90003, Quantum charger: 90004, Quantum Tube Adapter:10110
• Weight: Quantum: 64g, Shifty: 22g, BlakBullet: 12g, Quantum Tube Adapter:21g, giving a total of 119g
• Maximum cog: not applicable
• Total capacity: not applicable
• Pulley centre to centre: not applicable
• Index compatibility: everything
• Chain width: 3/32”
• Logic: top normal
• B pivot: not applicable
• P pivot: not applicable
• Materials: mainly plastics of various types

Ref. 2194