Identify Shimano components
 

I bought a Trek Pilot 5.0 and will be picking it up on Friday. I had to buy the bike via telephone because I am currently living in Santiago Chile. With the LBS they agreed to change out the cassette from 12-25 to 12-27. Lot of hills here and I will be using the bike to cross the Andes in March. I want to make sure that the new cassette they put in is the same quality as the specifications which are shimano 105. How do I identify the model Shimano cassette anyway?

Secondly this bike has Bontrager Race wheels and I have been all over the net trying to find what the rim width is for this wheel. Can anybody help?

Thanks, just joined the forum today..


Dennis