Cover for CB1100

[pekingduck]

I would like to get a cover for my CB to keep the dust off when sitting over winter and also for occasional nights I may leave it outside overnight.

I see a few on Amazon that are described as 87 inches or 91 inches, which I assume is the length laying "flat" (or am I thinking about this wrong?).

The bike measures about 84 inches, but our CBs have some width to them so I was considering 91 inch.

Could anyone give advice on this?  It is a small matter, but I'd rather buy the most appropriate size.

Since you have a luggage rack and, for now, a windshield.  I would recommend the larger size.  I would also recommend getting one that has markings on the outside. Nothing discourages putting on a cover than not knowing where the front is.  I use cotton covers on my bikes that are stored inside, but have marked the lower inside edges as left or right to make it easier to distinguish.