Originally Posted by
Yin_Yang
Ya I'm not a fan of the rear either...if and when he mails the 8 spd cassette, is it as simple as sliding it on, or does it get more complicated?
run the shifter in friction mode? you lost me lol.
In indexed shifting, one "click" of the shifter pulls (or releases) exactly enough cable to move the chain up or down one cog. Indexed shifters come in groups with derailleurs so that the length of cable moved with one click produces enough travel in the derailleur to move the chain exactly the spacing between two given cogs. Change any one of these elements (shifter, derailleur, cluster), and you MIGHT find that one click does not in fact shift one cog (all sorts of undesirable things could happen). Thus, if you change # of cogs in the rear, you may have problems shifting.
Friction mode is an option on most better quality rear shifters. Instead of moving the cable discrete distances between clicks, as in indexed shifting, in friction mode the lever moves continuously across its range, and it's up to you, the rider, to find the sweet spot for the derailleur so that you get your gear without any grinding of the chain against the derailleur or other cogs.
While this takes some practice, it instantly solves the problem of incompatibility between elements in the transmission, since you, not the shifter, decide where the chain will end up. The only issue might the the total cable that the shifter can pull, but if you're going from an 8 to a 7, that should not be a problem.
If you look closely at the shifter, you may see a little lever or a screw you can turn to change from indexed to friction (and back).