[QUOTE=Futurecat;21942392]
Originally Posted by
genejockey
It's the cage length that matters.
I was running a 2006 Centaur short cage rear on my Battaglin, but wanted to go beyond the 12-28 I was running (not as young as i used to be!), so I bought a new Veloce 10 sp medium cage derailleur that allows me to run 12-30. SO, if you were running a triple, I'd bet the derailleur is already at least medium cage. Measure the distance between the jockey wheel axle centers. If it's 55mm, you've got a short cage. 72.5mm, and it's medium, and longer than that and it's long. Since you've got a triple, it's really unlikely yours is short cage - you need the longer cage to handle the 20 tooth difference between small and large chainrings.[/QUOTE @
genejockey. I have to say .. you are the man! Great knowledge. I have checked and my derailleur, it is 90mm between the two jockey wheel axels, so must be Long.
Q1) Can I just unbolt the inner ring (30) from my current triple (52/42/30) and use the remaining two rings as a double (52/42)? I would use a 111mm Centaur Bottom Bracket instead of the current 115 Centaur Bottom Bracket to account for the removal of one ring.
Q2) If the above is not possible, I have see on ebay a true Veloce double 53/39. Can I use my 53 chain ring from my current triple on the new double? I have read somewhere that the BCD (Bolt Chain Distance) may be different? Any ideas?
The reason I ask is because the Campag Derailleur documentation states that there should be a max difference between Front and Rear teeth of 22 teeth.
If none of the above are possible, then I guess I need find some after market outer chain rings.
@akjphil Good to hear! Please keep me posted on progress.
no problem simply using the two largest chainrings on your triple. Before you remove the small ring, however, make sure that the low limit screw on your triple FD has enough adjustment to fully “lock out” the small ring, otherwise you might inadvertently shift to the non-existent small ring, with all the fun consequences that will ensue.
Not sure what is meant by “Max difference between front and rear teeth”. The main parameter you need to consider when setting up drivetrain components is Maximum chain wrap, the “tooth difference” between your big/big- and small/ small ring/sprocket combination. Calculated as (big sprocket minus small sprocket) + (big ring minus small ring). This number will determine the RD you need (ie short- vs medium- vs long cage). IIRC Campag short cage RDs are specced for a max chain wrap of 27 (eg, a 39/53 crankset + 13/26 cassette) but will likely handle a little higher. However, I don’t know that the RD cares about the relative sizes of the front and rear gears that contribute to that chain wrap number.