Does anyone make pannier-style instrument cases? I generally get annoyed when I am lashing my banjo to my bike and would like to be able to toss it on like my ortlieb's.
Actually...do any of the pannier makers sell the clip-on hardware separately?
Don't know of any off the top of my head. Colorado Cases...I think they have a website. Maybe use a HSC and rig some sort of bolt-on/bungee combo? Mount it at a 45 degree angle w/t neck part towards the rear and the resonator part down low around the axle. You may have a problem w/heel-strike, but maybe not. I wouldn't recommend a gig-bag in case of a fall.
I toured Ireland w/a mandolin and had a gig-bag wrapped w/a plastic trash bag. Worked out pretty well, but it was a cheap mando. It laid flat on the rack between the panniers and I had a sleeping bag bungeed over top of it to hold it in place.
When teaching guitar a few years ago I used a Reunion Blues gig-bag as it had double straps. Had a very small guitar...a Gurian S2-M, so there wasn't the weight of a banjo. Have thought of this many times as my wife and I plan on doing some cycle-touring and would like to bring a Mini-Martin, mandolin and flute. 'Instrument specific' panniers might be a nice 'niche' market as yet unexplored. PM me if you come up w/anything and I'll do the same.