rcd

I think I need some advice. I just removed the Shimano Ultegra rear derailleur on my wife's Cannondale T1 for boxing. On other derailleurs I've removed, I just turn the mechanism with a hex wrench until it comes off; reinstalling is simple. With this one, there seems to be a spring-loaded component. It came off NO PROBLEM. What worries me is getting it back on after the bike is shipped and she's trying to ride it! If necessary, it looks like I should be able to back off a small screw to reinstall the derailleur, then tighten the screw to get tension back on the spring. Is that correct? What will be affected if I don't get the screw EXACTLY where it was earlier today? Or is there some other way I need to re-install the derailleur without moving the screw from its original position? Kinda wish I'd not removed the derailleur now, and just tried to protect it with lots of bubble wrap..... Advice appreciated (from both me AND my wife!)

mechBgon

Rotate the whole derailleur back so the small screw is clear of the "claw" on the frame, then fasten the derailleur to the frame. That part will then swivel forward until the screw hits the claw. The screw adjusts the springyness of the spring in the upper pivot. If your upper pulley rumbles on the large cassette cog, then you boost the spring with that screw.

It's easier to swing the derailleur back clear of the claw when the chain's not on the front chainrings, since that leaves more chain slack.

rcd

Thanks very much. Good instructions and it all makes perfect sense! My wife thanks you too!

mechBgon

Kimmo

Try backing off that screw all the way - if your derailleur pulley doesn't hit the cogs you'll enjoy marginally quicker shifting.