I have a [Blackburn Outpost Frame Bag](Blackburn Outpost Bike Frame Bag https://www.amazon.com/dp/B075RNVGMJ/ref=cm_sw_r_apan_glt_i_3CGSEJBTREJYR5X74801?_encoding=UTF8&psc=1), size small, that I really like. On my medium frame, It's short enough that I can put a bottle on the seat tube, yet tall enough when expanded that it'll fit extra layers. And I have an extra cage on the bottom of the down tube. You might be able to fit a cage on the top of the down tube when it's not expanded, but I haven't tried it. https://i.imgur.com/9zfZd2c.jpg