The most reasonably priced component used on the Gl1500c Valkyrie 1999 (x) Japan Sc34-101 E-17 is the Bolt,flange,6x16.
Parts such as the E-17: Bolt,flange,6x20, B/brg Rad N/com, Holder Comp,trns, Shaft Comp,counte are included in the Gl1500c Valkyrie 1999 (x) Japan Sc34-101 E-17 parts fiche.
On this parts fiche the Bolt,flange,6x20 is the most specified component.