Great idea, thanks. If I don't come up with some bags to use before the trip I will def. pick up a small duffel bag from REI and use that.

 

My local army surplus store sells duffels in a variety of sizes, and their a bit cheaper than REI.

 

If there is any chance of rain, just stuff everything in a garbage bag.

 

+1 for a duffle bag and some tie straps.

 

I ride at least once a month 250mi + return following day. Duffel bag is all I use, strapped with paracord + bungees. It never even hinted about going anywhere the bag is very safe there. Being doing this over 20 times, also longer trips, never an issue apart that I takes me everytime 10mins to strap it the way I do. (I like overkill solutions though).

 

Always use bungee cords.

Do Not use ratchet straps.

Bungee cords hold the load secure. Straps allow your stuff to shift after it settles and the vibration and turns work on it. Years ago I lost a backseat my gear as I made a turn on a side street using ratchet ties on a trip.

 

+1 on a small duffel with cargo net. After you get some other luggage you can always use a duffel for some other purpose.

My road king is my first bike with mounted luggage. I did a lot of miles with an expandable duffel strapped behind me and an expandable tank bag in the front ( expanded upwards via zipper).

 

Get a trash bag and put it inside your duffel bag.
Place your items in sealed zip lock bags.
Place the sealed zip lock bags inside the trash bag then twist & stuff excess of trash bag into duffel bag and zipper.
Your stuff stays dry because of double protection, looks good on the bike and everything is tight.
Duffel bag and cord to hold.
Packing gets easier if you depart with old socks, old underwear and if possible old T-shirt.
Then you discard the old stuff.
Makes repacking for each departure easier also.

 

You could pick up a sissy bar bag. Lots of them on eBay in various sizes.

 

For something that carries a lot, take a look at http://revpack.mybigcommerce.com/seat-rack-bags/. Good quality with one large compartment.