Occasionally, when I shift from the 50T ring to the 34, the chain will
not drop to the 34 but ride on top of the space between ring. Skate.
I need to rerail the chain to the large ring and downshift again to
fix the problem when riding.
Rings are FSA. Confirmed 10sp by reading the codes stamped on reverse
side of large chainring. Shimano compatible
Campy Ergo Shifters with 2006 Chorus front derailleur. Derailleur
cage is parallel to chainring and ~2 mm above 50t ring. When tail of
rear derailleur is angled out slightly and the nose therefore angled
in, problem still occurs. In the small ring/large cog combination,
the inner cage of front derailleur is ~2mm from hitting the chain.
Chain doesn't drop off 34t ring. Even though Jump Stop is installled,
it has not been needed.
Chain is IRC DX10S and has not been a problem on other bikes. It is
almost new and has been checked carefully for 20 links and 12". I
used the Park tool as well. Lube is Prolink applied until wet about
every 2-300 miles and wiped next morning. Chain wiped after every
ride between major lubes. Chain length is proper. Big-big can be
engaged. Small/small, the chain does not drag the bottom of rear
derailleur.
The skating can occur occur across the range of cogs.
The 50t chainring may be worn but the chain drops cleanly off when I
shift in stand. I have not been able to get the chain to skate in
stand.
Would bending the nose of the front derailleur help?
Should I rotate the big ring on the crankarm?
Should I change the big ring? What ring is recommended?
Which order would you do the above?