The below string of questions from a reader are interspersed with answers from Shimano.
Question: I just bought a new bike, which came with Shimano 105. I’ve read several articles that discuss problems with the left shifter. Apparently, Shimano made a version that was intended for both double and triple. Many say the left shifter breaks very easily, and I’m concerned about my new kit. I also read Shimano scrapped that one and went back to a dedicated double or dedicated triple front shifter.
Shimano response : The current version of Shimano 105, designated by model numbers of 56XX format, has a dual control shifter that is both double- and triple-crank compatible. The switch to this format first occurred for the 1999 model year in an effort to simplify the line for bike manufacturers and retailers while adding versatility for cyclists. All Shimano components are actually subject to the same rigorous quality standards prior to mass production, whether they are Dura-Ace or Sora.
Q: Is there any way to tell if my shifter is one of the double/triple models? Or the later ‘corrected’ model?
Shimano response: One thing that Shimano does is consistently examine any products that are returned under warranty as well as monitor market feedback on the product. In doing so, there are often continuous improvements made in every product during its life cycle.
Regardless of when in the life cycle of the product your part the part was produced, Shimano has enough confidence in the product to offer a 2-year warranty (3 years on Dura-Ace and XTR). Non-conformances do occur occasionally, and when they do, they typically show up early in the product’s use. The shifter can be identified by model number, which is stamped on the plastic perch (under the rubber hood).
Q: Is there anything I can do proactively to prevent the shifter from breaking, other than upgrade?
Shimano response: The levers are designed to handle a variety of conditions and should function well with very little care. One of the easy things to avoid is shifting the lever in static conditions. This winds the cable without allowing the derailleur to move and puts excessive force on the internals. While this will not necessarily break the shifter, it does create a load that can impact the internals. Contamination of the lever and cables is the other issue to be aware of that can impact performance.
The shifter internals are well protected and some cleaning can be done will compressed air, but the best is to avoid getting too much debris on the internals. Cables and housing are easily replaced.
Responses from Devin Walton, Media Relations Officer, Shimano American