Micron and Micron QS were differentiated by the fact that:
RH lever had a composite, not a metal index spring mount ring, and an alloy fixing bolt that secured all of the internal components together from the rear, Torx T20 head (rather than the steel variation used in Chorus, 3mm AK head). The cable ratchet bushing was heavily drilled out and coated to give better cable relesae and a smoother action over the index springs.
LH lever was redesigned internally so that on a double system, from small ring to large, provided a QS FD was used with a Campagnolo 10s chainset with original rings (not copies) and a compatible cassette range (as this affects the compound angle that the chain comes away from the chainring at) and cable tension is correct, only one full sweep of the inner lever is needed to go from the FD as far left as it ever needs to be (adequate inner clearance on small ring / big sprocket) to as far right as it ever needs to be (correct clearances when on big ring and small sprocket). The full range of 10 sprockets at the rear was available on the big ring with no requirement to trim, the two intermediate clicks were used to trim on the inner ring only. This signalled a change from previous iterations.
If used with a triple, the QS left hand shifter utilised the first sweep to move the chain from small to middle ring and the next full sweep of the finger lever to take the FD from middle to outer ring where the ability to engage all 10 sprockets at the rear with no chain rub and no trim required was repeated, a differentator against the Shimano 3 x 10 road bike systems of the time. Intermediate clicks were used to trim on the small and middle rings.
The QS design philosophy was repeated on the Escape lever (albeit with a different, gated ratchet or escapement type mechanism), so it could be set up the same way, with no trim needed on the big ring provided all the specified preconditions were met.
The action on both levers was essentially the same as current UltraShift but to make the sweeping statement as above that they are "the same" is incorrect, as the internal components don't bear much relationship to each other. The physical mthod that is used to drive the internals in each direction is the same (sprung levers bearing a drive pawl that engages a drive ring) but the Micron (and all Gen 1 and Gen 2 levers that are not Escape mechanism) use two springs directly engaging an ungated ratchet, wheras UltraShift uses two clutch plates tensioned against each other with two (or in the case of a LH lever, 3) compression or thrust washers.
UltraShift LH levers are not suitable for triple systems, a specific Triple PowerShift lever was provided for Veloce, Centaur 10 and Athena 11 triple.
HTH?
Last edited by gfk_velo; 08-13-19 at 01:26 AM.
Reason: grammar, spelling, clarity