Frame bags

Where the heavy gear goes

The frame triangle is the only place low and central on the bike. That’s where tools, spare parts, food and water in a soft reservoir belong — anything dense. You barely notice a well-packed frame bag when handling the bike, whereas the same weight at the saddle or handlebars has an immediate effect.

Five positions, five uses

• Front top tube, 0.75 to 2 L : just behind the stem. This is the bag you open while riding — for your phone, energy bars and power bank.
• Rear top tube, around 0.8 L : against the saddle, clear of your knees. The same capacity, but inaccessible while riding.
• Down tube, around 1.2 L : beneath the tube, for things you rarely need.
• Half-frame, 2.5 to 6 L : occupies the upper part of the triangle and leaves room for a water bottle below it. It’s the best compromise for most bikes.
• Full-frame, 6 to 9 L : fills the entire triangle. It offers the most capacity in the range, but it takes away the bottle cage mounts — you’ll then need to carry your water on the fork or handlebars, or in a soft reservoir.

Strapped or bolted on

The standard attachment uses hook-and-loop straps around the tubes and works with any frame. Several recent models bolt directly into the two or three threaded inserts found on the top tubes of modern gravel bikes and mountain bikes. It’s neater and completely secure, but you need those inserts at the correct spacing: check your frame before ordering a bolt-on version.

Measure up and protect the paintwork

For a half-frame or full-frame bag, measure your frame triangle along all three sides rather than relying on the bike’s frame size: two frames of the same size can have different triangles depending on the slope of the top tube. And watch out for rubbing : the straps rub against the paintwork with every pedal stroke, and a derailleur cable housing trapped between the bag and the tube wears quickly. Protective film at the contact points solves both problems.

To find out more: How to plan your cycling route

See also: Bikepacking bags · Saddle bags · Handlebar bags