Tailfin, known best for its aero rear racks and rack bags, has developed yet another on-frame bag, this time sitting at the rear terminus of the top tube, directly in front of the seatpost. The new Rear Top Tube Bag rounds out (or maybe triangulates?) Tailfin’s already solid menu of frame, toptube & downtube bags.
Tailfin describes the space in front of the seatpost as an often-overlooked area to add practical, easily-accessible storage, without the interference to pedaling that can happen with larger volume top tube bags. In addition, they says that their new Rear Top Tube Bag addresses common shortcomings in other rear top tube bags, such as instability, bulging, water ingress, poor zipper access, and aesthetic compromises. Tailfin suggests that this Rear Top Tube Bag spot is most useful for storing tools and spares.
Although, it could clearly be perfect for a diagonally-cut 1/2 sandwich, as well.
Great things in a small package for MTB, Gravel, or Road
The Rear Top Tube Bag’s minimal appearance hides a wealth of small intelligent designs, that Tailfin says come based on years of testing.
On the surface, Hypalon and Ripstop Nylon fabrics are 3D-welded together with a waterproof zipper to create a seamless, tapered, and fully watertight package. Tailfin’s patented Zipper Gutter maintains waterproofing despite its reversed zipper orientation. But importantly, this back-to-front zipper orientation enhances access and visibility of what’s inside, especially helpful on small frames or when dropper posts are lowered.
Inside, a lightweight structure of diagonally-aligned carbon struts offers reinforcement. And a removable insole cushions contents, also making the interior easy to clean without detaching the bag from the frame. Outside, Tailfin’s next-gen V-Mount system offers multiple frame attachment points with their TPU Cargo Straps.
Combined, this design is stable and prevents deformation, ensuring effortless one-handed zipper use.
Tailfin Rear Top Tube Bag – Pricing, options & availability
The new Tailfin Rear Top Tube Bag comes in two versions, both available now, sized and shaped either for MTB or Road/Gravel.
The 0.8L Road/Gravel version of the Rear Top Tube Bag weighs 109g and features a taller (139mm high), narrower (36-45mm wide) profile with a trailing edge angle of 100° to match nearly horizontal toptubes and common dropbar bike seat angles. The 0.9L MTB version weighs 112g and has a wider (42-50mm), shorter (124mm tall) profile with an 85° angle, better-suited for sloping MTB toptube layouts.
Both Tailfin Rear Top Tube Bag for either Road/Gravel and MTB sell for the same $80 / 70€ and include 3 stretchy Cargo Straps. In most cases, Tailfin thinks you’ll just use 2 straps around the toptube, but there are attachment points at the back to secure the bags to the seatpost if you plan to carry especially heavy gear inside.
