If you like to carry more gear than you can fit in your pockets but don't like that big sweaty hug feeling that a full pack gives you then the Osprey Seral Lumbar Bottle Pack may be just the thing you've been looking for. This pack includes a 1.5L hydration reservoir and sits on your hips, leaving your shoulders free to breathe.

Who's this item for: Riders that want to carry more gear than they can fit in their pockets but don't want to carry a big ol' sweaty pack. Lumbar packs offer free movement and a more compact solution than typical over the shoulder packs.

Strap Style: This is a lumbar pack so it sits on your hips without any shoulder straps. The bike-specific angled hip belt and compression straps keep the pack close to your body for outstanding stability and comfort. The back panel has extra thick ridged foam with a central air channel and the straps themselves use an airmesh fabric to further assist with ventilation and breathability.

Materials: Bluesign approved, PFC-free and DWR coated 900 x 600D Polyester main with a 400HD Nylon bottom.

Hydration bladder capacity / Bladder style / Valve style: The Seral includes a quality 1.5L Hydrapak reservoir with a Blaster bite valve for a strong flow of fluids with every sip. The hose magnet allows you to quickly secure the hose when it's time to drop back into the trails.

Helmet carry: There is no helmet carry feature on this pack.

Internal organiser pockets: The Seral 4 has enough storage capacity for ride essentials, such as a spare tube, CO2 and multi-tool and, of course, snacks. There is a large zippered main compartment with a reservoir sleeve with tool organisation and an internal zippered pocket

Dimensions and Weight: 4L Volume, 19.05H X 31.75.0W X 11.40D CM , 370g

Pros: A really well thought out lumbar pack with heaps of features to ensure that you can carry your gear securely and in comfort. The 1.5L bladder allows you to carry plenty of fluid with you in comfort.

Cons: There is still a bit of a stigma attached to lumbar packs, bum bags, or whatever you want to call them, so you might lose some cool points with your buddies if they haven't tried one out for themselves yet.