Your best bet would be to fit a set of 17in Magteks,(expensive and getting harder to find), dont know why you would want to fit 16.5,that will probably limit you to race tyres only and you will probably have difficulty finding 16.5 rims narrow enough, you could also try and source a set of Honda RS250 NF5 17in rims, as these are magnesium and light as a feather.
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