I used to live in Cambridge, Mass. and I was born just outside Harvard Square. There used to be a bike-shop on the outskirts of Harvard Square called the Bi-Ex - short for Bicycle Exchange. And a few on Mass. Ave. towards North Cambridge. I did my business at Harris in Newton, or Laughing Alley in Allston. I remember the one by MIT - but never checked it out. Too busy living in MIT's research libraries.