Just found out something interesting: I checked the 2007 Specialized catalogue. In it, the Tricross Sport, Tricross Comp, and Tricross Expert are said to have the same geometry.

Sometimes catalogues are not as reliable as firsthand measurements.

I checked a shop, and compared the chainstay lengths on the sport and the expert. The sport has longer chainstays. No question.

It might be interesting to take a tape measure with you, or borrow one (or some kind of measuring device) at the shop, and take the measurements firsthand. You can't always go by published data.