Originally Posted by
Doohickie
I know- old thread- but... okay, I recently got a 1987 Schwinn Prelude with the Shimano Light Action derailleur. It had aftermarket friction stem shifters on it. I just came across a set of S424 shifters. I notice the specs for the Prelude in the catalog say "SLL-434 S.I.S." levers. Will the 424s work? Also, they came in a zip lock bag with all the parts loose. Can anyone point to an exploded drawing or provide directions about how to get these puppies put together?
SLL-434 SIS is a bicycle oxymoron, as SL = shift levers and the second L = Light Action (friction version). An S immediately preceding the numbers indicates Light Action (SIS version). The correct designation for the SIS levers would have bee SL-S434. I suspect someone at Schwinn was just being sloppy, as even the hyphen is misplaced. Both the SL-S424 and SL-S434 were 6 speed SIS shifters, so there is no reason they should not work in your application.
Originally Posted by
Sixty-Fiver
I think that if Suntour had been first out of the gate with a successful design they would have offered indexed systems at all levels instead of using Shimano's trickle down approach to marketing which has served Shimano quite well.
With all due respect, that is exactly what you do not want to do. Implementing a technological change across the board is a major financial undertaking. If it works, you're a genius, but if it fails, the company could be ruined. And that is almost what happened with SunTour. In 1987, they introduced AccuShift on 5 road groups and 4 ATB groups. First generation AccuShift was an underdeveloped product that was rushed to market, in response to SIS. Performance was poor and, coming immediately on the heels of the failed Tech series of derailleurs, the bicycle manufacturers lost faith in SunTour and market share plummeted from 60% to 30%. Of course, SunTour had to take that gamble. If they had waited, Shimano would have been steadily gaining market share. Unfortunately, the gambled failed and a huge chunk of market share was handed to Shimano on a silver platter.
Shimano had the luxury of being first and therefore could mitigate risk by introducing indexing on a single group. If it worked well and was accepted by the public they could accelerate the introduction the following year. If not, the majority of the groups were still conventional and they would not lose much market share. It was unlikely that other manufacturers would follow on a lackluster introduction and Shimano could take the time to analyze the results, redesign and introduce an improved version. This is the approach they used to indexing. It had gone through a constant refinement process since 1975, in the forms of Positron, Centeron and New Positive Mechanism. The course Shimano was taking was readily apparent, but Campagnolo, SunTour and others were either blind or conceited.