A snug but not tight cockring around my whole junk for long periods is not about sustaining an erection. It's just about being pleasantly 'held', more easily bigged up some with the slightest arousal, and about sporting a handsome bulge especially under close fit denim or the like. So, in light of all that, cycling with a slightly soft [eg] leather ring around the tackle is just, well, pleasant. That's all.
Si.