Okay, Iíve done my homework (Lennard Zinn & Sheldon Brown) and searched the forum, and I still have a question. If itís in the wrong place or Iíve missed a relevant post, feel free to point me there, please.
I need to know if I need to replace my cassette, but itís a bit more complicated than that.
Iím recently back into biking after many, many years away. I bought a Giant OCR 3 (no giggles, please), with an 8-spd, 11-25 cassette. I thought I took decent care of my chain this winter (according to the instructions from my highly respected local LBS), but after 1200 miles, much of it rainy and post-snow roads (plus way more hours on my rollers, too) I recently noticed some skipping and a slight grinding or crunching feeling/sound when I pedal. Waited a couple weeks (b/c didnít know what it was), then last night, looked it up in Zinn, and then measured the chain three times: Almost 1/16Ē too long (just a tiny hair under). Thus, tretched, should be replaced, according to Zinn and Brown.
I looked at the cogs Ė they donít look too bad to me. No dramatic hooking/shark finning, very little deep scratching, etc. But I am no expert. So, LBS this morning confirmed the chain should be replaced Ė AND the mechanic told me ďYou have to replace the cassette, too.Ē It just seemed like a knee-jerk thing, maybe what they tell everyone. I donít think he looked at the cassette first. I asked a few qís Ė ďDo you mean chain is stretched too far and so itís a sure thing cassette should also be replaced?Ē Answer, yes.
Zinn says you should replace cassette if chain is 1/8Ē too long Ė not 1/16Ē. Itís possible I mis-measured last night. Iím definitely not an expert, just getting back into the sport. LBS has a good rep, but their svce. Depít has been known to be shoddy at times. So, my radar is up: Am I getting an ďup-sell?Ē What do you think?