Top Tube Bags
These bags fit on the top tube of a bicycle, just behind the stem. Some models fit under the saddle, also on the top tube. The most popular size is Large Century Bag, unless you need to stow a “monster-sized” smartphone, in which case you may want to step up to the x-large model. They are called “Century Bags” because of the many roadies and now, gravel riders, participating in iconic 100-mile rides all across the U.S.
We now have a special model for mountain bikes since they have steeply sloped top tubes.
Order of size (photo below): Small, Medium, Large, X-Large and Brevet (click on photo for larger image). The MTB bag is similar in size to the Large, but angled differently in front.