Hi- I am trying to compare bikes and have two general questions. First, what effects do various subtle changes in geometry mean? For instance, in comparing two bikes, a 56cm Raleigh Cadent FT3 and the 20" Trek 7.6fx, I find one with a wheelbase of 1011mm and one with 1061. What is the effect of the longer wheelbase? Top tube lengths? What is the effect of changes in these various geometries?

Second question: how does one know what components are an upgrade over another manufacturer's bike? It is next to impossible to compare different manufacturers components let alone comparing within a manufacturer. For instance, which is better Shimano Deore or Shimano 443 or Shimano Deore or Tiagra? I looked at the Shimano website and without a pricelist in hand, it was not terribly informative.

The Raleigh is $100 or so less but I believe the components are better on the Trek. The Raleigh fits a bit better (I wish Trek had a 21" or worked in cm like the rest of the world) but last time I bought a Raleigh I really wished it better components on it.

Thanks for any wisdom imparted.