Tailfin has spent the past few years steadily refining the art of on-bike storage. Everything started with their innovative rear system, and over the last few years they have developed all types of on-frame storage solutions. With their latest release—the Rear Top Tube Bag—they’ve turned their attention to one of the most overlooked areas on a bike frame: the space in front of the seatpost.
Designed around real-world use
The bag comes in two purpose-driven designs, one for road and gravel riders, the other for mountain bikers, each tuned to the geometry and riding style of its intended use. Despite the differences in angle and width, both versions prioritise minimal interference and quick, one-handed access to essentials on the move. The road/gravel version is narrower and taller, with a volume of 0.8L for a weight of 109 grams.
While most rear top tube bags tend to compromise on stability or ergonomics, Tailfin’s version tackles those pain points in the best way. The signature V-Mount system provides a rock-solid connection to the frame, while internal carbon battens give the bag structure and prevent it from bulging outwards or rubbing against your thighs.
Details that matter
Tailfin’s focus on usability and durability is clear in every detail. A seamless construction using welded Hypalon and Ripstop Nylon ensures full waterproofing without the stiffness or bulk that can make some bags unwieldy. The zipper runs from front to back, which is unusual but functional, allowing easier access even on compact frames or with dropped saddles. It’s backed by a smart internal gutter system that protects against water ingress while keeping the silhouette clean.
Inside, a removable, shock-absorbing insole protects your gear and makes post-ride cleanups easy. The bag’s overall layout reflects its main purpose: to carry tools, spares, or other small items in a way that’s accessible, quiet, and stable, even on rough terrain.
Expanding the system
As with all Tailfin gear, compatibility is a key strength. The Rear Top Tube Bag is designed to integrate with the rest of the brand’s frame bags, allowing riders to mix and match setups depending on the ride or terrain. It’s a small addition to the lineup, but one that makes clever use of space that’s often ignored.
For those who want their gear to work as hard as they do, this latest release is another strong argument for Tailfin’s continued place at the forefront of performance-focused bikepacking design. The product launch is complemented by a short film in which the actual product engineer shows the process behind the ideation of the Rear Top Tube Bag in British humour style.
