Note that in this thread Jim and Jan use the common term "cable stretch" for the phenomena that really should be more accurately identified as "cable housing compression." You can read the full thread here but I've quoted Jan Heine as he makes the case thusly:
From: Jan Heine
From: "Jim Bronson"The problem you describe is not inherent with cables, but inherent with indexing in the shift levers. Moving the indexing to the derailleurs would solve the problem. The cables could stretch all they want, but the indexing adjustment would not change. However, indexing in the derailleur also would mean that you could use any shift lever. And Shimano invented indexed shifting specifically to make you buy a group, including their shift levers (and freewheel). Then they combined freewheel and hub into a cassette hub, so you had to buy their hub, too. Then they combined their brake and shift levers, so you had to buy their brakes, too. Then they combined their cranks and BB, so you had to buy the set as well.
What you fail to mention is that the electronic system has the capability to eliminate the need for mecanical cables, which would be an increase in reliability from my standpoint. If it wasn't for cable stretch, we'd never have to fiddle with our derailleurs.
The obvious solution is to forego indexed shifting altogether and use friction shifting. I employ it on my bikes, and I don't ever worry about cable stretch, nor do I fiddle with my derailleurs. And I can combine any components I want (Maxi-Car hubs with Shimano freewheel, Huret derailleur, Simplex shift levers, Mafac brakes - no problem at all on my PBP bike).
In addition, downtube shift levers give you a warning when the cable frays at the shift lever (where it usually frays) - the sharp ends poke your hands. (In case you ignore the warning, or the cable fails elsewhere, replacing a shifter cable in the field is easy with downtube shifters, too.)
Finally, downtube shifters let you move your hands around every time you shift, thus preventing hand pain and numbness on long rides.
Maybe, once all the problems with electronic shifting have been worked out, and the system works off my generator hub (I think Shimano is working on that, their latest generator hubs provide more power at low speeds to make this possible), I will consider it. Then I'd want voice activation, too. Just like I say on a tandem to warn my stoker: "Shift" and the new gear comes in. Based on my cadence, the system will know whether I want an upshift or downshift.
In the mean time, the old Alex Singer will have to do.
140 Lakeside Ave #C
Seattle WA 98122
From: Russ Loomis
To: email@example.com, Jan Heine
Bravo!!! Jan Heine! I could not have said it better myself. I also use down tube friction shifters on all my bikes ( after having tried STI for over 5 years ) and thus eliminated all the shifting problems of index shifting. They are cheap, reliable, and last a lifetime but the best feature is that I can use any cassette or freewheel combination from 5 spd - 10 spd. It also puts the riding experience back into riding. Like driving a stick instead of an automatic. Fun.
I have become so put off with the bike industry pushing "newer and better" down our throats when they are the only benefactors. Put friction back on your bike; you could even save almost a pound in weight ( for all you weight weenies ) and ride worry free of having a bike fail during an event.