The biggest spokes they sell on the normal cycle market that I can find easily online are 11 gauge (3mm or .120") but there are tools made for spokes up to 8 gauge. Good luck finding something THAT big though
lol no wonder i cant find any info on this hub. probably no one else has figured out the spoke size. i am going to ask the bike shop if they found 11 gauge.
but i may just have one more trick up my sleeve....just waiting for my cash....