I searched for a long time for a bag that meets multiple use cases and looked good on my sliver-gray steel all-around bike, and I found it in the middle earth.

I wanted a bag that can stay on my all-around bike on the handle bar or sometimes the rear rack for a wide range of uses:
- About town: a place to pack my purse + jacket - with expansion space to pick up groceries
- Working at coffee shops: purse + iPad or 13" Macbook
- Weekend day tours: space for a camera in a bag, extra clothes, larger tool kit/medical kit, snacks

The middle earth does all that--although for a big grocery run it needs to move to the rear rack (big = 1/2 gallon milk, two big things of yoghurt, 12 eggs, two containers of berries).

This is not a bag that's easy on/off the bike (I have another one for my ebike that's much quicker)--but because it's a bit tricky to remove I don't mind leaving it on there and just taking out the contents when I go into a store.

The one challenge I still have: my handlebar mounted light won't work unless I make the bag as small as it can be. I might end up buying a braze-on mounted stub so I can move it if I really need light for night rides. (The flashy works great during the day on the front of the bag, though.)

The perfect medium sized rack-less bag. I bought this bag to complement my Velo Orange Biggish Bag (also made by Road Runner). The sizing on my Middle Earth Jammer ran large which is perfect. The expandable/collapsible volume makes it perfect for carrying a variety of items, including those bulky ones. Looking forward to many more years with this well-crafted bag!

This bag has room in depth and width to carry my computer and some goodies without adding too much weight. This bag alleviates the sweaty back effect when riding with a backpack. When I called Road Runner, the team member was knowledgeable and friendly. She was also willing to do a custom order! RAD!!! After using the bag for a week, it is clear that this bag can handle rain and salty air. For those will short bars, this is not your bag. Also, if you have longer bars, you might want to invest in a foam spacer kit. The bag takes a lot of real estate on the bar. There are some sweet little easily-accessible front pockets that are great for carry those tiny essentials, like a credit card and cash for that cool coffee shop on your route to work.
The bag quality is durable and waterproof. The straps are smart with several attachment points. The buckles and connectors are top notch. I can't wait to order more bags!!!

I was looking for a handlebar bag to use on a multi-day bike tour, and wanted something that was easily put on and off the bike (vs the widely used Ortlieb handlebar bags). I found the Jumbo Jammer during a random internet search, and decided to go with the slightly smaller Middle Earth size. The bag is awesome! It worked perfectly on my folding bike (Bike Friday) and it doubled as my smaller carry-on for the flight. I encountered a few deluge downpours and not a drop of water got in. Everything about this bag is perfect: Construction, size, function. Just get yourself one!

Love the MEJ, but it takes away my hand position on the tops of my drop bars. Maybe if RR provided foam spacers with longer straps?