Saddle Bags and Frame Bags

A saddle bag and a frame bag are two compact bike bags that each have a different function and mounting position. A saddle bag hangs under the saddle on the seatpost and is intended for repair material: a spare inner tube, tyre levers, a CO2 cartridge or mini pump and possibly a small tool set. It is the standard emergency kit that virtually every road cyclist and triathlete takes along on every ride, because you cannot fix a flat tyre on the spot without material. A frame bag mounts on the top tube of the frame, directly within reach while you ride, and is intended for nutrition: energy gels, energy bars or salt tablets that you want to grab on the way without stopping.

In this range you will find saddle bags in compact and XL format, from basic models for an inner tube and two tyre levers to roomier versions that also hold a mini pump and tool set, and aero saddle bags in a teardrop shape that limit air resistance. The frame bags are available in volumes from 100 to 500 ml, in nylon versions for daily use and carbon look versions for a sleeker appearance, and as an aero bento box for directly accessible nutrition on or beside the handlebar. The choice depends on how much you want to take along, whether you want to carry purely repair material or also nutrition, and whether aerodynamics and weight play a role in the choice.

Which saddle bag or frame bag suits you?

The right choice depends on what you want to take along, how long you ride and in which position you can reach the bag most easily.

You want to take repair material along for training sessions and races: choose a compact saddle bag. A basic model offers room for a spare inner tube of 700c or 26 inch, two tyre levers and a CO2 cartridge. That is the minimum emergency kit for an outdoor ride. A compact saddle bag mounts via a click system or velcro to the seatpost and the back of the saddle and is mounted or removed in a minute. For shorter rides and races where you want to keep the weight as low as possible, a mini format is the most practical.

You also want to take a mini pump or more tools along: choose a medium or XL saddle bag. A larger saddle bag has room for a mini pump alongside a spare tube, tyre levers and CO2, and possibly a small Allen key set or repair kit. On longer training rides or multi-day rides on which you want to be able to fix mechanical trouble independently, a larger saddle bag is the right choice. Before purchasing, check whether the bag fits the height of your saddle and the width of your seatpost: some XL models are too large for saddles with little free space underneath.

You ride a triathlon bike or road bike and want as little air resistance as possible: choose an aero saddle bag. Aero saddle bags have a teardrop-shaped or streamlined exterior instead of the round or rectangular shape of a standard saddle bag. They hang tightly under the saddle and reduce the turbulence that an ordinary saddle bag creates at the rear. Aero saddle bags are somewhat more expensive than basic models but are the choice for triathletes and time triallists who want to be aerodynamic in the small details too.

You want to take nutrition along that you can easily grab on the way: choose a frame bag on the top tube. A frame bag mounts via velcro or zip on the top tube of the frame, directly in front of you within reach of your hands. You grab an energy gel or a bar from the bag while you ride, without taking your hands off the handlebar for long. A frame bag of 100 to 200 ml holds two to four gels; a model of 400 to 500 ml also holds a bar or two alongside the gels. Choose a volume that suits the duration of your ride and how much nutrition you consume on the way.

You want to have gels ready directly in front of you on or beside the handlebar: choose a bento box. A bento box is a soft, compact nutrition holder that mounts on the top tube just behind the handlebar or on the stem and has a wide opening with which you quickly grab something with one hand. Bento boxes are popular among triathletes and road cyclists who take a lot of nutrition along over shorter distances and who want to have everything directly accessible without searching in a more tightly closed bag. They typically hold two to four gels or a snack bar.

What to look for when purchasing?

Saddle bag or frame bag: which function are you looking for?

First determine whether you want to store repair material or carry nutrition. Repair material goes in a saddle bag: you rarely use that material and it does not need to be quickly accessible. Nutrition goes in a frame bag or bento box: you grab those items several times per hour and they must be directly accessible while you ride. Most road cyclists and triathletes use a combination: a saddle bag with repair material at the rear and a frame bag or bento box for nutrition. This way you never have to stop while riding for something that is in your pockets or out of reach.

Volume: how much has to fit in?

For repair, the required volume is predictable: a 700c inner tube, two tyre levers and a CO2 cartridge fit in most compact saddle bags. If you also want to take a mini pump along, you need a medium model; if you also want a tool set or a second inner tube, you choose an XL model. For frame bags, the volume depends on how long you ride: count on a gel per twenty to thirty minutes during intensive effort and choose the volume that suits your training length. A frame bag of 200 ml is sufficient for a ride of an hour; for longer rides or for extra bars, 400 to 500 ml is more practical.

Aero vs. standard for saddle bags

Standard saddle bags are cylindrical or rectangular in shape and sufficient for training sessions and recreational rides. Aero saddle bags have a streamlined teardrop shape that reduces the air resistance behind the saddle. The aerodynamic advantage is measurable at high speeds but is less relevant on training rides than during time trials or triathlon races. Aero saddle bags are also often tighter at the opening, which makes it take a little more effort to put material in: that is a small price for the streamlined shape. Choose an aero model if you do triathlon or time trials seriously; choose a standard model if you purely want to ride and do not make a priority of the aerodynamics of the bag.

Closure and access

Saddle bags usually close with a zip, sometimes combined with a roll closure or a clip mechanism. A zip gives quick access but can come open with vibrations if it is not properly closed. Roll closures are more waterproof and safer but require more handling to open. For a frame bag or bento box, a wide opening or a zip that you operate with one hand is the most practical, because you reach the bag while you ride. Check whether the opening is large enough for the material you want to put in: a narrow opening is awkward if you want to store a wider mini pump.

Mounting and compatibility

Saddle bags are attached to the seatpost and the underside of the saddle via a click system, velcro or buckles. Check the maximum seatpost diameter that the bag accepts: thicker seatposts of 25 to 31 mm occur on modern carbon bikes and do not fit in holders that are designed for standard diameters. Frame bags are attached to the top tube via velcro: check whether the width and length of the bag fit the top tube of your frame. Some frame bags are also available with attachment via the water bottle screw points if the frame has them on the top tube.

Our advice: start with a compact saddle bag for repair material and a small frame bag of 200 ml for nutrition. That is the most versatile combination for both training sessions and races. Supplement the saddle bag with a mini pump or CO2 pump and a repair kit, and put two to three gels in the frame bag for a ride of an hour and a half. This way you are prepared for mechanical trouble and always have energy at hand without the combination being heavy or bulky.

Need help with your choice?

Would you like to buy a saddle bag or frame bag but are you not quite sure which model best suits your wishes and needs? Then we are happy to help you further with all your questions. You can reach our triathlon specialists by phone on +31 (0)413-256800, send an email or visit our triathlon shop in Volkel, the Netherlands.

Frequently asked questions about saddle bags and frame bags

What is the difference between a saddle bag and a frame bag?

A saddle bag hangs under the saddle on the seatpost and is intended for repair material that you rarely need but always want to have with you: a spare inner tube, tyre levers and a CO2 cartridge or mini pump. A frame bag mounts on the top tube of the frame and is intended for nutrition that you want to grab while riding: gels, bars or salt tablets. The core difference is accessibility: the frame bag is directly accessible while you ride, the saddle bag you generally use while standing or after getting off. Most road cyclists and triathletes use both bags at the same time: saddle bag for repair, frame bag for nutrition.

What do I keep in a saddle bag?

The basic contents of a saddle bag consist of a spare inner tube matching your tyre size, two tyre levers and a CO2 cartridge with adapter or a foldable mini pump. With that you fix a flat tyre without help from outside. Optionally you add a small Allen key set or a multitool for small adjustments on the way, a master link in case your chain breaks, and extra patches or a repair kit for a second flat tyre. Some athletes also keep an energy gel or cash in the saddle bag as an emergency reserve. Also take a look at bike maintenance for repair kits and accessories that you take along in your saddle bag.

Which frame bag fits my bike?

Frame bags are attached via velcro to the top tube and fit most road bikes and triathlon bikes with a standard round top tube. Before purchasing, check the width and length of the top tube of your frame: a frame bag that is too wide slides on a narrow tube and a bag that is too long does not fit in front of the stem. Some modern frames have an oval or integrated top tube on which not every frame bag fits well. Frame bags of the XLAB Stealth Pocket series are designed for a compact mounting on triathlon bikes with limited space on the top tube. For nutrition on the bike, frame bags are ideal in combination with sports nutrition that you consume on the way.

What is a bento box and is it different from a frame bag?

A bento box is a soft, compact nutrition holder that is attached to the top tube directly behind the handlebar or on the stem, with a wide opening with which you quickly grab one item while you ride. It is smaller than a frame bag and offers less volume, but the opening is often larger and more accessible. A frame bag has more volume and is suitable for several gels, bars and loose items. A bento box is the choice if you want the nutrition to literally lie in front of your nose and you can grab one gel with a quick movement without reaching into a larger bag. For longer rides where you need more nutrition, a frame bag is handier; for shorter rides or races where you want everything exactly in front of you, a bento box is ideal.

How do I attach an aero saddle bag and who is it suitable for?

An aero saddle bag is attached in the same way as a standard saddle bag: to the seatpost via a clamp ring or click system and to the saddle via velcro or buckles. The difference is in the shape: the aero saddle bag has a streamlined exterior that reduces the air resistance behind the saddle compared with a round or rectangular bag. Aero saddle bags are suitable for triathletes and time triallists who also pay attention to small aerodynamic details, and for athletes who want to give their bike a neat, integrated appearance. They are less suitable for athletes who open and close the bag frequently, because the opening of an aero bag is sometimes narrower than that of a standard model. For recreational training, a standard saddle bag that is simpler and cheaper is sufficient.