I have installed a set of the paired 16 spoke Shimano 575's that I had as a spare set for my mountain bikes, on our mountain tandem.
These were offered several years ago by Shimano and are rim and disc capable.
They seem to be strong enough and we don't feel any squirm while standing with our team weight of 300 (200/100).And so far are as true as they were when new.
They look very much like the offering from Santana (Sweet 16) as to the spoke anchor design and hubs.
Has anyone had any experience with these wheels on their tandem ?
They seemed to be bomb proof on my single mountain bikes in cross country competition.