At least I think it is... I hope you can help me, girls. I have a tripple chain ring in front. I ride a 50cm Bianchi Eros Donna - I hear it has a really short wheel base and I don't know if that contributes to my problem. Here's the problem. Apparently, on some tripple chain rings, if you are on the middle chain ring in front, and the smallest in back, it sort of acts like it's cross chained. I was doing a really big hill ride a couple of months ago and when I was in the middle chain ring and the smallest on in back, my front derailleur decided to shift me in to the smallest chaing ring in the front. It was such a hard hill that I proceeded to FALL OFF MY BIKE! I was all irritated, and got back on, shifted to a slightly harder gear behind and left it in the smallest chain ring in front. Then, as the hill got even steeper, the stupid chain randomly shifted all the way off the front chain rings! I FELL OFF MY BIKE AGAIN!!! I was SO mad! So, I took the bike the my friend who is a bike mechanic and he told me about the effective cross chain thing. I haven't had the bike in the middle chain ring in front and the smallest behind since then. Last night, I went for a hard hill ride thinking this problem was solved with some tinkering by my friend, and it happened again! I wasn't 'cross chained', and I didn't fall off, but I did have to stop on a big hill! So, I left it in the smallest chain ring in front and shifted to a slightly harder gear behind and kept riding. Now my chain would sort of 'clink' occasionally - like if it was hitting something - but it wasn't. Can anyone diagnose this? I have had the chain measured and it isn't too stretched out (was about 25% stretched at the beginning of summer). Maybe I should have it remeasured? Is this a major front derailleur problem? Is this a 'cog' problem? Do you think I will need a new front casette? Or rear casette? Sorry for the long post!