105 FD Moving
Of course it is moving, but what I what to know is why the physical position is changing.
I have a 2009 Allez Compact Double with 105 and the FD has twice more out toward the big ring while riding to the point where it will not shift to the small ring.
Today on a Century at mile 88 (I was tired and moving slower than normal) I tried to shift to the 34 ring. The brifter worked correctly, but after the second "pop" that normally shifts the FD there was a loud bang from the FD and nothing happened. The crank stopped moving for a second, but since I as soft pedaling that didn't do much, and then the cranked turned normally and I had DR rub, but was still on the 50. Trimming took care of the rub. When I got back to the barn I check the FD. It moves its normal stroke, only it is out away from the bike about half the width of the cage more than it should be. If I try to shift down the cage rubs the outside of the chain, if I try to shift back the cage rubs the inside of the chain. But the chain stays on the 50.
I looks like the FD has physically moved out, but I don't see how that could happen. I checked if it could be pushed back in and it is solidly attached to the seat tube. It does not look bent.
This is the second time it has happened on this bike, but the first time it was under load, so I assumed that I had goofed. This time there is no question that I shifted correctly. The bike is still under warranty, so it is going back tomorrow.
My question is what is going on with this bike? My Tarmac has never done this. I have always thought that 105 was just a little heavier and a little less smooth, but just as reliable. The last time the shop fixed it they said it "just needed adjusting." I know how to adjust the FD so it will work, but why would an FD get that far out of adjustment in one normal shift? Has anyone seen this before?
Thanks in advance.