I have a size XL cover on a DL 650 with Jesse luggage (large square panniers), Givi V46 topcase (big one), and a tall windscreen (V-Stream). It is a tight fit, but covers everything. The foot peg straps just barely reach at max stretch. It fits more comfortably with just the top case; or with side bags but no topcase. Since I normally take the top case into the motel or tent and leave the Jesse pannier mounted, this works out well. WIth no luggage, it simply covers more of the back of the motorcycle. In all cases, the seat, tank bag, and electronics stay dry in wind and rain. I wouldn't want to try a smaller size with any topcase or side bags.
1 year, 9 months ago