FVM

Hi,

I recently snapped the rear derailleur on my daily bike by a branch getting stuck. I work at a local bike shop and saw that in the used cabinet there was a ultegra 6600 rear derailleur in next to new shape so I offered my boss 40 bucks for it instead of getting a new crappier derailleur for the same price. On my rd bike I have a 105 5701 (basically is the 5700 but can take 2 xtra teeth on the sprocket). So what I did was swap out the 5701 105 for the ultegra 6600 on my rd bike and put the 105 on my daily bike. I know the 6600 is a bit older then the 5700 models and also know there is lots of trickle down tech, hence I am constantly going back and forth on it in my head if that was the right decision. hoping maybe some of you could share your opinions, could be that I am splitting hairs. Its a 10 speed ridley rd bike.

Iride01 

No idea what you are really wanting to know.

Since you bought it, install it and see if it works. You might need to make certain what cage length you might need. If your rear sprockets are too big for the SS version you might need the GS version.

datlas 

Coke vs Pepsi. Nearly the same but not quite. If it works for you, that's what matters most.