Bike frame bags: top tube, half and full frame

Which frame bag format should you choose?

• Top tube bag: less than a litre, sitting on the tube behind the stem, it keeps bars, gels, your phone or a power bank within reach without stopping.
• Half-frame bag: around 3 to 6 litres, hung under the top tube, it leaves the lower part of the triangle free for one or two bottle cages. The most versatile format for gravel riding and light touring.
• Full-frame bag: it fills the whole inside of the frame and offers the largest volume, but your bottles then have to go on the fork, under the down tube or in a backpack.
• Seat tube or down tube bags: small cases for tools, sometimes bottle-shaped so they fit in a bottle cage.

How do you choose the size to suit your frame?

Measure the inside of the triangle: the length under the top tube, the height available along the seat tube and the space down to the down tube. Half-frame and full-frame bags come in several sizes, from small to large, to follow frame geometries. A small frame, a frame with a steeply sloping top tube or a full-suspension mountain bike, whose shock occupies the triangle, leaves little volume: go for a top tube model or a compact half-frame bag. Finally, check that the bag lets the bottle come out of its cage.

Mounting, rubbing and width

Most bags attach with hook-and-loop straps around the tubes; an extra strap around the stem or head tube stabilises top tube bags. Over the miles, the straps rub on the paint: a protective film applied at the contact points prevents marks. A bag that is too wide touches your knees with every pedal stroke; choose a slim profile, especially on a road bike.

Waterproofing and packing

Water-resistant models use a coated fabric and a zip protected by a flap; waterproof models have welded seams and a waterproof zip. Put heavy, dense items in the frame bag, such as tools, food or a power bank: low and central, they weigh less on the bike's handling than in a saddle bag or handlebar bag. Keep your phone and snacks in the top tube bag, within reach while riding.

Other bikepacking and touring bags

A frame bag combines with a saddle bag for light items and a handlebar bag for extra volume. For heavier loads, pannier bags attach to a pannier rack.

Which frame bag brands should you choose?

Blackburn offers its Outpost Elite frame bag in three sizes, small, medium and large, as well as a top tube bag.

Osprey offers the Escapist range: small, medium and large frame bags, and a Wedge version for the angle between the tubes.

Zefal, an accessories maker from the Loiret in France, covers the top tube with the Console Pack T2 and T3 and the Z Adventure T3 with a waterproof closure, and the triangle with the Z Adventure C4.

Agu gathers its bags in the Venture range, with medium and large frame bags, tube and top tube bags, and a Venture Extreme version.

Zipp, an American brand in the SRAM group, designs its Speed Box 1.0, 2.0 and 3.0 for triathlon and time trials: a streamlined box sitting on the top tube.

Topeak offers the MidLoader in 3, 4.5 and 6 litres for the half frame and, for the top tube, the 0.75-litre TopLoader, the Fuel Tank and the FastFuel.

Bike frame bags on sale

Find end-of-line models in bags and luggage clearance and the latest products in new arrivals. Before setting off on a trip, the summer sales are a chance to complete your kit.

Frequently asked questions

What size frame bag for my bike?

Measure the triangle of your frame and compare it with the bag's dimensions, leaving a few centimetres of margin around the bottle cages. If you are torn between two sizes, the smaller one is less likely to rub and leaves your bottles accessible.

Can you keep your bottles with a frame bag?

Yes, with a half-frame or top tube bag. A full-frame bag means moving your bottles to the fork, under the down tube or into a hydration pack.

Does a frame bag damage the paint?

The straps, and the dust that gets under them, eventually mark the frame. Protective tape at the contact points and tightly fastened straps that do not move limit the wear.

Is a frame bag suitable for a road bike?

Yes, in a slim version: a top tube bag or a narrow half-frame bag is enough for a long ride or an audax, without getting in the way of your knees or weighing the bike down.

Which frame bag for an e-bike?

On an e-bike with the battery in the down tube, the triangle often remains free for a half-frame bag. Avoid covering the display or the controls and keep access to the battery if it is removed from the top.