We're in a larger market (San Francisco) and we've got commercials for bike shops -- not typically individual brands (like Trek, Giant, etc).

Television advertising is pretty cost prohibitive. Most bike shops have yellow page ads, a website, and possible some flyers or direct mailing during the year. That's it.

Also, the audience for cycling advertising is pretty darn small.

As mentioned, a more effective marketing tool is sponsorship -- in many forms. Offering in-store clinics and events brings your potential market into the shop. Sponsoring a club, team, or charity training program brings lots of exposure. Hosting a ride from the shop brings folks to your door on a regular basis. Email list marketing is pretty darn effective, especially in newsletter, value-added format.