You've GOTTA
check out SBR, on Punt Rd (on your way back from perving down Chapel St.), near the Nepean Hwy, Princes Hwy (St Kilda) junction. They usually get my vote for sexiest shop -- they even have a coffe machine and trendy Euro-trash employees
Fitzroy Cycles is definitely worth a look, and their shop in Carnegie (Princes Hwy) ain't bad either
Cecil Walker is a small shop, but the last time I was there they had a gazillion frames haging up
Richmond Cyclery (Bridge Rd) is ok, I guess, but not really worth hiking to specifically