A CL65 ON SHORT APCH TO SFO RWY 28L SUFFERS A WAKE TURB ENCOUNTER FROM THE PRECEDING B777 AHEAD AND TO THE R ON SHORT FINAL TO RWY 28R. THE CL65 PERFORMS A GAR.

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WE WERE IN THE PROCESS OF MAKING A VISUAL APCH TO RWY 28L AT SFO. ATC WAS SETTING UP SIMULTANEOUS VISUALS TO BOTH RWYS 28L AND 28R. WE HAD PREVIOUSLY RPTED A B777 IN SIGHT ON VISUAL TO RWY 28R. ON APPROX 1/4 MI FINAL AT 400 FT AGL; WE EXPERIENCED TURB AND UNCOMMANDED ROLL. PF INITIATED A GAR. I NOTED FMS COMPUTED WINDS 035 DEGS AT 10 KTS. OUR SECOND VISUAL APCH AND LNDG WERE NORMAL. WIND CONTINUED TO BE 035 DEGS AT 10 KTS AND UP TO 17 KTS. SFO TWR DID ASK WHY THE 'GAR.' I EXPLAINED TO GND CTL THE WIND SIT; AND HOW WE UNDERSTOOD THAT THE TWR CTLR HAS NO WAY OF KNOWING ABOUT WINDS AT THAT LOCATION. I SUGGEST THAT ATC MAKE 'WINDS ALOFT' REQUESTS FROM THE NUMEROUS FMS EQUIPPED ACFT IN THE AREA. THEY SHOULD THEN PARALLEL APCHING ACFT AND MATCH SPDS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR HAD NOTHING MORE TO ADD THAN THE INFO SUPPLIED FOR THE WAKE TURB RPT. RPTR FELT THAT HAD THE ACFT BEEN ABREAST OF EACH OTHER THE INCIDENT WOULD NOT HAVE OCCURRED. INITIAL SPACING IS EVERYTHING; ALONG WITH PARALLEL SPDS FOR THE APCH.