Ortlieb

It's a good product, but.. The attachment process to the handlbar is a bit fiddly, dealing with the strap when using it as a bar bag is exceedingly fiddly, and the extra straps to secure it are annoying and I can't see the need so I don't even use them.

The magnetic closure is very well designed, the bag has a good amount of storage space, it's lightweight, and not ugly. All in all, despite my comments above, I do recommend it, as it appears to be the best solution for a moderately sized, lightweight bar bag (I looked at a bunch of alternatives).

I already had several non-Ortlieb top tube bags, and I wanted the convenience and added security of a quick-release system that would allow me to bring my valuables into a market with me and didn't require me to fiddle with rethreading and adjusting straps each time I got back on.

The Ortlieb Fuel bag and Top tube bag use the same mounting system. Ortlieb offers the Ortlieb Mounting-Set to support the use of the same bag across multiple bikes. But if you are handy with an awl or hot nail, you can modify the bags you already own.

This system works very well in retrofitting other top tube bags. All the hardware you need to attach the quick release to your bike is included. I converted a Timbuk2 bag to take advantage of the M5 frame bosses. The included internal bag fasteners provide enough rigidity to remove the four frame and stem straps from the bag and rely solely on the bosses.

I no longer have to worry about:

1. straps wearing down the bike frame and stem finishes

2. a top tube bag flopping from side to side

3. leaving valuables or an expensive frame bag on the bike when I head into a store or overnight accommodations

Finally, if you pick up a couple of these, you can quickly move one bag between bikes and swap bags on your bikes depending on the ride's needs.

I have both the 4.1L and the 1.6L sizes. There isn't much point to the 1.6L since the 4.1L can fold down to almost the same size.

The 4.1L can hold all the tubes and layers for a multi-day ride/brevet.

The sturdy seat rail clamp stops any swaying of the bag.

The clamp doesn't work well with some seats/seat-rails, especially if the seat is pushed all the way forward on the seatpost. It works fine on my Pro Stealth seat.

These panniers were an upgrade from a cheaper REI double sided one that I used for a while. I found my old set wasn't keeping my clothes dry (I primarily use these for commuting) on rainy days and wanted a set I could use not only for commuting but bikepacking down the road. These are everything they say they are and then some. Very simple fool proof system for attaching to all of my bikes (a commuter gravel bike and a fat tire bike). They transfer easily due to the simplicity of the latch system. Also, the latch system is super durable. The material is extremely durable; it's sustained a couple decent wipeouts with minimal damage and is completely waterproof. Not a drop of water gets in. I kayak as well and the design is similar to my kayaking dry bags. The volume of material they hold is a huge upgrade as well. I'm able to fit everything I need for daily commuting in 1 of the bags. Great purchase, simple design and looking forward to years of heavy use out of these.