BAe 125 Series 800
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 7000; Flight Crew Type 4000
Situational Awareness
Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Requested ATC Assistance / Clarification
Procedure; Environment - Non Weather Related
During climb to FL360 (.70M 1800 FPM); encountered a very hard 'hit' of what felt like wake turbulence.  Encountered a very brief and rapid positive loading; followed by a very brief and rapid negative loading.  It felt like we drove over a speed-bump at 410 knots; it was that rapid and hard.  Flight crew members and passengers were restrained by shoulder/lap harnesses.  We asked ATC if there were any 'heavy' aircraft proximate to us.  They advised there was a B757-200 15 NM to our NW (1:00-2:00 relative position).  FMS computed winds aloft at FL340 were from the north at 21 knots.  No injuries and no damage to aircraft.
HS-125 Captain reported encountering wake turbulence climbing through FL340; probably from a B757 15 NM to their northwest.