BarryG wrote:
> Would appreciate comments from anyone who has set up a Chorus 10sp
> triple FD to work with a Ritchey WCS triple crank (Ultegra 118 bb).
> Does the FD shift well? Enough outward throw to accomodate the wider
> bottom bracket, etc?
I've set up Chorus Ergo systems with Chorus triple front
changers on many and various triple cranks although not that
crank specifically.
If I might, I think your comment about the 118 spindle bears
a brief overview-
In square taper, spindles match crank. A crank designer can
put the chainrings at any given chainline with just about
any spindle length because he is free to change the
relationship between the crank's taper area and the seats of
the chainrings. Moreover a crank designer can increase or
decrease overall tread ("Q") if he's so inclined at a given
chainline with just about any spindle length. There's no
rule that the outside face of a crank has to be flat.
(There's nothing inherent about modern cranks sticking out
so darned far either)
In listening to customers, I find common misperceptions
about this. If you removed a Centaur and its ACH 111 and
replaced it with a classic TA on a symmetric 132mm spindle
you'd hardly change the front derailleur adjustment.
OTOH, if you put a Centaur triple crank on a TA spindle you
could walk your dog between chainring and chainstay. If you
put a TA triple crank on an ACH BB the inner ring would hit
the frame before you tightened it.
To your specific question, Ritchey specifies ISIS for the
WCS mountain and OCTA for the other 4 WCS designs.
Both systems are standardized for singles on 108, doubles
113 and triples 118.
So, yes, your Ritchey crank is designed for a 118 OCTA and,
yes, your Chorus triple front will span that or any triple
crank with a reasonable chainline.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
