[Euro Cruiser]

Amgine, think of biminis as coming in two generic categories: one set will expand out/fold up like an accordian and typically they consist of one full width bow, anchored to the sides of the cockpit, with one or two smaller bows which hinge part way down the main bow. This is the typical 'Caribbean charter boat' bimini, they are tensioned by the use of webbing straps when expanded, easily folded up when necessary, and a bit flimsy for full-time cruising & offshore passagemaking...tho' still found on some cruising boats. The other category are intended to be left up in a rigid form (altho' it's a simple matter to remove the canvas if e.g. leaving the boat for a while), it is likely to have both vertical stanchions supporting one full bow and with horizontal braces that rigidly connect the second bow to the first. This is the kind that you'll most often see a solar panel 'rack' built on top of.

By 'stanchion', I'm referring to vertical stainless tubing - just like your lifeline stanchions - that are mounted in pairs, e.g. each side of the companionway or equally spaced along the cockpit's aft coaming. The top ends are mounted onto a full-width bow and the bottom ends attached to the cabin trunk or coaming, respectively. This means the bow is anchored at both ends and along its port/starboard run, making it fairly rigid. With this kind of support, moving up from 1" OD tubing is not necessary in the smaller boats we sail. E.g. I can chin myself on the stanchion-supported bow of our bimini.

Jack