Wike appears to confirm alloy spokes on the SD, Steel on the bigger engines bikes, extract posted below.
Construction
To manufacture the Comstar wheels, Honda used an extruded aluminium-alloy rim made by D.I.D[17]: 37  that was fastened to the spokes using aluminium rivets. The spoke pieces were bolted to the hub with steel bolt and nut fastenings in either three, five or six pointed star configuration. What metal the spokes were made from depended on the model of motorcycle. The CB400T, for example, used steel for the spokes and alloy for the rim, whilst the CBX and the Super Dream used alloy for both the spokes and rims to further reduce unsprung mass. For the NR500, the wheels were made from magnesium, with titanium used for the fasteners. This type wheel was considered "maintenance free" with no user serviceable parts, and Honda had "Do Not Disassemble" stamped on the wheel rim alongside other markings such as the fitment size. : 49  Composite wheels were also cheaper to produce than their cast alloy equivalents.[18]: 42 
