I've figured out how to tell if a bike store is interested in service as part of their business or just wanting to sell new bikes. If they sell 27 inch tires, they are with you for the long haul. Otherwise, their bottom line figures exclusively on the number of new bikes rolling out the door.
We have a new bike store in town. They have a glitzy showroom. Not much in the way of tools, parts, or panniers. Just a big room full of shiny new bikes. Oh, and no 27 inch tires.