Ideal for gravel riders, commuters and bikepackers who need 15 litres of weather-resistant storage without fitting a rear rack.
The PRO Gravel Bag Seatpost 15L is a spacious bikepacking seatpost bag for gravel riding, commuting and longer self-supported adventures. With 15 litres of storage in one large compartment, it gives you room for spare layers, food, tools and other ride essentials while keeping your setup simple and rack-free.
Its waterproof construction helps protect your packed gear when the weather turns, while the anti-swing design helps keep the bag stable over rougher surfaces. The seatpost mounting format is easy to integrate with a gravel or adventure bike, provided you have sufficient clearance between the loaded bag and rear tyre.
For items you need to reach quickly, the external bungee cord storage provides a handy place to secure an extra layer or other lightweight equipment. Reflective trim improves visibility in low light, and dedicated mounting points let you add a rear light or other accessory. Choose it when you want substantial carrying capacity in a straightforward, weather-resistant seatpost bag.
15-litre capacity
Carries clothing, food, tools and bikepacking essentials for longer gravel rides, commutes and overnight trips.
Waterproof construction
Helps protect the contents from wet weather during changing conditions.
Large single compartment
Provides one straightforward packing space for bulky or irregularly shaped items.
Anti-swing design
Helps limit side-to-side movement so the bag stays more settled on rough gravel surfaces.
Seatpost mounting
Adds substantial storage without requiring a pannier rack.
External bungee cord
Keeps additional lightweight items accessible outside the main compartment.
Reflective trim
Adds visibility when riding in low-light conditions.
Accessory mounting points
Allows lights or other accessories to be fitted to the bag.
General
Materials & construction
Compatibility
Features
Pro is a cycling component and accessory brand focused on contact points, tools and finishing kit for road, gravel, mountain bike and triathlon riders. Its range covers handlebars, stems, saddles, seatposts, bar tape, workshop tools and on-bike accessories, with product development centred on fit, function and rider feedback.
The brand is closely linked with high-performance cycling and develops products through collaboration with riders, designers and Shimano Dynamics Lab. Pro supports elite athletes across multiple disciplines, but its catalogue is aimed broadly at riders who want practical, performance-led equipment for everyday riding and racing.
