I think the biggest handlebar bag that attaches to a bracket on a handlebar is Carradry, they claim 9 lites. At about 8 liters, look at Toppeak for that. I think the largest Ortlieb is about 7 liters. I do not know what the size on Arkel is, but that is another option.

I have a couple different handlebar bags in the 9 liter range that have been out of production for about a decade that were made by Louis Garneau, and these needed a lot of reinforcing because they sagged really badly. After a decade of use, the zippers are getting quite worn.

I need a separate waterproof cover for rain on mine, the Toppeak likely needs that too.

Anything bigger, it probably will need a rack to sit on. And those are more niche market bags.

Keep in mind that the handlebar bags that have a bracket on a handlebar that is quick release is REALLY nice to have when bike touring, you can take your bag in the restaurant or convenience store with minimal hassle. Many, including my Louis G bags take about five seconds to remove the bag from the bike. A rack mounted one, could be quick if on a decailer (spell?) type rack but might have lots of fiddly straps too.

If you get a wide one, make sure it will work if you use brifters, see below.




If you decide to get a conventional handlebar bag that attaches to the handlebar, I prefer my bag lower and a bit closer to the handlebar, I use a second stem to mount my bags. I wrote up a long post on that at this link:
Racks/Bags and Interrupter Levers

I recall a thread several months ago on this forum, someone was trying to use an old camera bag, but I have no clue how that ended. Looked like a great idea at
the time, but those bags are not very waterproof, lack structure, lack ways to attach to a rack.

Randonneuring, I like a smaller bag in the 7 liter range, it is a bit lighter and the bike handling has less flop over at low speeds, I use a small Carradice saddlebag for stuff that does not fit in the handlebar, like extra clothing layers, etc. Bike touring is where I want the 9 plus liter handlebar bag.

Good luck figuring this out.