Upgrade questions-index shifting

Typically, index shifting systems are designed to work together as a group: the shifters are designed to work with the derailleurs and the cassette spacing. You cannot really get away with mixing and matching and have a workable system. Within one manufacturer's component group you can mix and match: Ultegra shifter/brake levers with Dura Ace derailleurs with a 105 cassette. Bike manufacturers do this all the time to put higher priced components onto lower price-point bikes.

To answer your question, the answer is no, you will not end up with an indexed shifting system by just replacing the rear derailleur: you will need new shifters, derailleur, cassette, freehub, and, if you are going to do front indexed shifting, new front derailleur, and possibly a new crankset. At this point you might as well buy a new bike.

EdPed said:

I have an older bike I really like. It has the freewheel w/ friction shifters. My question is-Is the indexing in the levers or the derailleur? In other words, could
I convert to a cassett with a newer derailleur and be able to shift it with my friction system? Cost of parts is a major factor in this research. Also, I know I'll
need a new hub and spokes, but will I need a new wheel?
Thanks. EdPed

The indexing is in the levers. You can get a new derailleur as long as it is the same make as your shifters, same with other components. There are one or two exceptions to the rule though, SRAM shifters with Shimano mechs (although this applies to mtb parts).

PCC-I do not care if I have indexed shifting or not. Friction is fine if I wind up with more gears. EdPed

EdPed said:

PCC-I do not care if I have indexed shifting or not. Friction is fine if I wind up with more gears. EdPed

The indexing is in the levers, and as the others say, to get proper indexing, the derailleur, cassette, and levers need to be compatible. However, the original question was about friction shifting, right?

If the shifters are functional, they will work with the newer cassettes. I have an early 80's Trek coverted to commuter with original Suntour friction Power shifters and a campy 9s cassette and 9s chain with Veloce rear derailleur (of course with a campy rear wheel). The amount of lever throw to shift gears is smaller than with the 6s system that it replaced, thus requiring a little more finesse, but all told it works well--not as good as indexed, but better than the old freewheel set-up. If I see a nice deal on Ergo 9s shifters, I might complete the upgrade, but for now I'm putting about 50 miles/week on this set-up.

Many on this forum think old bikes aren't worth the effort or money, but you can significantly modernize a quality old ride without breaking the bank. You could rebuild the old rim with new hub/spokes, but probably be cheaper and easier to pick up a pre-built rear wheel.

Maybe I mis-read your original post. If you are using friction shifters then you can mix and match all you want, pretty much.