The only help I can offer is that there has to be a lighter rim out there than the RR1.1
I use the 32h ones on my brevet bike (465g/ea). The 28h are OK at 415g (IIRC for the single eyelet version), but there are lighter rims out there.
OTOH, depending on your application, anything lighter and you may be sacrificing strength; and the RR1.1 is a rim you can beat the snot out of.
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"I feel like my world was classier before I found cyclocross."
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