I have a hardware store and am looking for an outlet for bike parts for all brands from cheap bikes on up.
I get most of my parts through Amazon, usually either Amazon or Niagara Cycle.
Nigel
One of the regional sports stores with a great bike section gets their parts from Wilson Bicycle Sales. Can't speak for the service, but the prices are pretty good and competitive at the store.
You probably need to find some store owners and ask them where they get their parts. Perfect to do if you go on vacation to another part of the country.
AndrewB
I'll agree with Nigel about Niagra Cycle's Amazon Storefront. They are a little high on a few things BUT worth it in shipping speed and accuracy!
Good maintenance to your Bike, can make it like the wheels are, true and smooth!