On Sat, 9 Aug 2003 17:06:15 -0500, Grenouil
wrote:
Rick - read the 'oracle' - Sheldon Brown's site at
http://www.sheldonbrown.com/harris/index.html

Of course...I never thought to look there for
routine info, just the wacky stuff!

You can use a double RDR with a triple crank, but depending
on how you size the chain you could have some slack when
using the smallest ring and some of the smaller rear
sprockets, or a nasty experience when you inadvertently try
to use the largest ring and the largest sprocket if the
chain is too short. Probably better to get a triple RDR.

I think I can shift carefully. Do I dare find out?

An alternative to a triple is to use a 'wider' cassette
and/or smaller chainrings. The largest rear sprocket for
most 'road' dérailleurs according to the Shimano spec is
27T, but lots of people report using 30 or even 32 - the
disadvantage is bigger gaps between adjacent sprockets.

I can handle the wide ratios. I don't need 9 gears all
a single tooth (or two) apart from eachother.

The smallest chainring you can use on a 130mm BCD crank like
the Shimano 105 is 38T, so to go smaller you'll need a new
double crank with a smaller BCD.

Hmm...I could put a wider cassette and a new double
crankset with a smaller small ring...that may be an
option.

--
Rick Onanian