A1 and A2 is the different versions using silver adjusters (A1), and black adjusters (A2)…I think
Silver adjuster – More common with the earlier externally routed Reverbs which also had the silver coloured post collar. The remotes with Silver speed adjusters will not work as a replacement for a remote with a black coloured speed adjuster, as they both move different amount of fluid and therefore are not compatible. So if you replace one, make sure it has the same colour speed adjuster.
The silver and black collar on the post are universal and will fit each other, the only thing to ensure is that the remotes are compatible, so remove a remote with a black coloured adjuster, then replace with the same.
MMX – Just the Matchmaker for the SRAM shifter mount, which can be removed if you’re not using it.
Think that’s it, hope it helps
Exactly this.
The colour of the collar does not make the post A1/A2. The internals (and subsequently the lever assembly) however, DOES.
As an additional note, simply changing the silver/black adjuster barrel on the lever cannot convert the lever from A1 to A2 or vice versa.