Downshifting a Campy 53/39 Problem
 

Good morning everyone,

I followed all of the directions when setting up my 2008 Centuar group (53/39) on my Cinelli frame.

Yesterday while out riding, I down shifted going up a hill, to the small front ring. I did not relax very much when I shifted. The chain fell off the small front ring and I had to stop to put it back on.

Is there something I need to check/adjust or technique I need to learn so this does not happen again?

I shifted up and down many times afterwards, relaxing when shifting in the front, and I did not have it happen a second time.

Thanks in advance

Make sure your limit screw is set correctly. There should only be about a 1 mm gap between the chain & derailleur cage when in the 39/ big gear in the rear. Also, adding a Deda Dog fang is good insurance, check out the pics from Tour of Flanders, even pro's bikes like to have a little insurance against dropped chains.

Also be sure your cable tension isn't too high.

It's easy to adjust your limit screws. They keep the derailleur from moving too far, so the chain won't fall off. Park Tool has a detailed derailleur adjustment page. Scroll down to "Front Derailleur - Adjusting L-screw".

You'll probably want to adjust the H-screw, too.

Even when everything is adjusted correctly an occasional chain drop will occur. I've just made it a habit of easing on my pedal stroke every time I downshift to the little ring. I can't remember how long ago I dropped my chain the last time.