I ended up with the Topeak V beam rack on my Civante and it’s worked out great. Despite the one mounting point - the seat post - it has not given me any problems with moving or wobbling around.
They make three versions - the V drops the rack down a little lower which seems to be the best choice for the Yamaha frame, at least. I have the trunk bag shown, which while it is a great bag, annoys me because it’s so high and involves some gymnastic leg maneuvers climbing on and off... I added the frame kit that allows hanging panniers on the rack but still doesn’t add any other mounting points. I’ve got some small Giant panniers that work great, so lots of choices.
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