I have an Y2K Trek 1000 that I've been riding recently. I enjoy it very much. However, I'm not in love with the thumb shift button on the Soras. So I bid $70 on a set of 105s off of fleabay - and won! (I didnt really expect that bid to win. lol!). I know that I will need to switch to a 9 sp cassette and swap chains too. My question is will the existing Sora derailleurs be OK or do those *have* to be swapped out, too? I believe my riding level would be categorized as recreational/hobbyist.
I know some will say not to sink money into an older bike like that. And, truthfully, I plan on moving to an Allez eventually. Since I figure the 105's will move over I could justify this one upgrade.