Lygon Cycles - a bike shop quite close to CERES. They are on Lygon St near Brunswick Rd.
Ivanhoe Cycles - a good sort-of local bike shop, particularly if you are after womens bikes.
St Kilda Cycles - considered by many to be one of thes best bikeshops in Melbourne. These guys are renouned for customer service, have a very wide selection of bikes including speciliast bikes, and a very impressive range of lights and lighting accessories.