Mobile dérailleur...?

[IainC]

So here's a question I think I know the answer to, but the combined wisdom here will soon prove otherwise I'm sure .

I have a rather nice (IMO!) carbon framed FC3 with alu dropouts and hanger. So far so good, but the rear shifting has always been a little finickity to get just right. Yesterday's transport of bike to work for a lunchtime pootle involved removing the wheels to get the bike into my car (sorry cycle to work fans, but my work is 50 miles from home). Reassembled bike for ride only to find my rear shifting had gone to pot again with an inability to shift to the largest cog at the back, and a spare and ineffectual click of the shifter when on the smallest cog. So far so simple- a tweak of the cabling and all's back to normal.

I wondered what the issue was and started looking in more detail as to what was going on when back at home. One thing I noticed was that the rear derailleur moves significantly when tightening my QR skewer. Possibilities- normal, bent hanger, or something more serious? As the QR skewer pulls the frame together, I reckoned that it's probably expected, but I'd welcome thoughts and expertise from those here...

 

[Koga]

The tension on the skewer will have a small affect on the position of the sprocket relative to the derailleur,

Also consider that your wheel after removing and re installing may have has settled slightly different.

You can also consider, when you transport the bike you may "stretch" the cable if you "over" turn your steering wheel to get it in the car ?

When I adjust the rear derailleur I always find that there are one or two sprockets only just right (for me normally the middle ones).

 

[boydj]

If it's a removeable derailleur hanger, then the bolt holding it on may need to be tightened.