Originally Posted by
twocicle
Merlin nailed the discussion concerning the Pro trend of matching rim & tire widths for aerodynamics.
Also, as discussed in the "19mm rim" thread, using tires that are much wider than the outer rim width will increase the amount of tire "flop" while cornering. So, if you are looking for performance (ie: high speed) cornering, going with a wider tire on a narrow rim is not the best setup.
IMO, you would be better off first looking at the rim widths and profiles the pros are using (med-tall & wide ie: >= 21mm), then match an appropriate tire.
Well, my
ENVE 65 clinchers have a rim width of 22 mm, so I think they are probably okay. Better might be the more aerodynamic
ENVE SES 6.7, which has a rim width of 26/24 mm front/rear, and thus is more in keeping with wider rim widths that populate the Giro. Unfortunately, the SES's (molded) spoke holes are limited to 20/24 front/rear (vs. 28 on the 65), which are too few for a tandem.