A specialized impact dummy for research into the feasibility of motorcycle mounted devices which are intended for protection of riders has been developed and is specified in ISO 13232. The ISO motorcyclist dummy specification is based on a Hybrid III dummy with modified capabilities and characteristics for comparative tests involving motorcycle/car impacts and considering the tendency for three dimensional dummy motions and forces. Special characteristics include: 32 channel internal data recording system; instrumented frangible upper and lower leg bones; three degrees of freedom frangible knees; helmet compatible head form; a neck torsional module; and other modifications to provide for motorcycle compatibility. Technical requirements and the research basis for the key components are presented and discussed, along with suggestions for possible future refinements.