I guess there's Mascot Cycles on Church Street if you like Bianchis and Ray Bluchers weirdness, or 'Total Rush' on Swan Street if your world revolves around Specialized worship. Is that all? Can't think of any more, haven't lived in Richmond for a few years.
CBD, yeah, there's quite a few in walking distance - SHM has a fair amount of bling I guess, and Cecil Walker is always good fun to go in and stare at the ceiling hoping you'll spy some sort of frame of loveliness (Although unfortunately most of them will be yellow Cecil Walkers and Cannondales).
If you come to Melbourne, you'd be mad not to go and have a bite to eat down Brunswick St in Fitzroy, so you may as well pop in to Brunswick St Cycles in the North end and Fitzroy Cycles which is sort of central.