My chain and shifting was having some issues. I replaced the chain which was stretched beyond the 1% mark on the chain tool. Shifting improved significantly. However, with the chain so stretched and about 2,000 miles on the cassette, I figure I should swap that out as well. I honestly can't tell if cassette is worn out or not. I will tell you this, I was in the granny gear (or thought I was) going up a steep hill, standing up, and the chain made a crunching sound and I assume popped into the granny geat at that point. Sign of bad cassette? Or just a derailer needing adjusment?

If I had to guess, the cassette, which was new prior to 2K miles being put on it, probably had that stretched chain running through it for at least 1K miles...maybe more.

Here's my question - I plan on bringing bike in for a tuneup to LBS. I just ordered the cassette (Sorry, LBS - $50 instead of 80-90). Should I wait until I get and install the cassette THEN get the tuneup? Or is it immaterial? That is, will whatever derailer adjustments made will not change when I put in new cassette. the new cassette has same teeth, just going from a 105 to an Ultegra.

I kinda of thing the unamimous answer will be that I should wait, but just want to confirm. Rain is in the forecast, so I figured good time to drop off the bike.