# Info on Shimano Light Action group



## Gimpie7 (Oct 25, 2007)

Hey y'all. I just bought a late 80's Centurion Le Mans RS with a shimano light action group on it. Its a 6 speed with indexed shifting on the downtube. I have done some searching and haven't been able to come up with any info on it. I was wondering if anyone on here has any expierence with them and what they think. Thanks.


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## FatTireFred (Jan 31, 2005)

Gimpie7 said:


> Hey y'all. I just bought a late 80's Centurion Le Mans RS with a shimano light action group on it. Its a 6 speed with indexed shifting on the downtube. I have done some searching and haven't been able to come up with any info on it. I was wondering if anyone on here has any expierence with them and what they think. Thanks.




"light action" is just a descriptor of the shifter, no?


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## wim (Feb 28, 2005)

*You asked for it.*

Found this in a newsgroup some time ago. Dry reading, my italics.  

_Light Action: Shimano's moniker for their improved rear derailleurs with
lighter parts, and a weaker non-adjustable coil return spring 
replacing the older design's adjustable torsion spring_. All
Shimano off-road derailleurs from Acera-X to Deore XT went to
this light-action design in 1994, XTR followed in 1995. While 
improving the quality and ease of shifts, when combined with RF+
shifters, it produced dismal results when matched to gripshift
or Shimano's own thumbshifters. Also the shifting was only smooth
and easy when the bike was showroom fresh and clean, add some mud
to the drivetrain and performance went right out the window. In 1996
shimano introduced stiffer return springs (although still non-
adjustable) back into the upper level rear derailleurs. _Although some
of the road derailleurs also went to light action, the top-3 models
(105SC, Ultegra 600, and DuraAce) did not._


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## Gimpie7 (Oct 25, 2007)

yeah i kinda figured it had its problems. Just an excuse to upgrade


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