I think there are many fixed gear bicycle store near LA thou,
mine is road bike, so it is hard to find information about good bike store in LA area.
I want to purchase new stem, handle bar, and break lever thou,
would you please recommend some nice stores in LA?

thanks!

Ted Ernst in Manhattan Beach is an active retro guy I'm aware of, I'm sure there are others...

Does Ted have a shop?

Yes, I think its called Ernst! Odd hours though.

This shop is a must see:
https://velopasadena.com/