As I get older I build up more bikes with triples. My rule of thumb for a double to triple conversion is to add 5mm to the drive side of the BB spindle. I don't know if this supported by science or engineering, but it works for me.
Top
__________________
You know it's going to be a good day when the stem and seatpost come right out.
(looking for a picture and not seeing it? Thank the Photobucket fiasco.PM me and I'll link it up.)