Bike Trunk Bags

The term “bicycle trunk bag” typically brings to mind a do-it-all bag with a simple design, and small stature. But trunk bags can be defined as any bag that can mount to the convenient spot atop your rear rack. Trunk bags come in various shapes and sizes and their usability spans many types of cycling. From light commuting, to traveling, to long touring expeditions, trunk bags are a quick and easy solution for increasing carrying capacity on a bike.

A commuter style trunk bag is sleek and easy to use for quick trips. Made for convenient access to cargo, trunk bags are designed to face backwards in relation to the bike for easy opening while the bag is still attached to the rack. A carrying handle or shoulder strap is usually included as well for easy mobility off the bike. Trunk bags can attach to racks in a few different ways. The most popular styles utilize Velcro® straps. Other trunk bags have a specially mated bag-to-rack compatibility system, which allows you to more quickly pop the bag on and off the rack as needed. Commuter trunk bags, can equip a Towney bike with enough capacity for comfortably commuting to work with a lunch, a spare jacket, and other small necessities.


Rack Packs may be considered the most standard or traditional style trunk bags for touring. These bags work best when used in conjunction with a pair of rear panniers. By resting over the top of the panniers, the Rack Packs can be cinched down tightly with the side straps, using the panniers on each side as an anchor. Rack Packs can hold bulky items such as a tent and sleeping bag, freeing up your pannier space while protecting your gear from the elements. The large carrying capacity and the waterproof roll-top closure make Rack Packs a favorite among enthusiasts who enjoy multiple outdoor activities. As a multipurpose bag with a convenient, boxy shape, the Rack Packs easily transform from bike bag to a shoulder bag, great for hiking and cycling areas, or for just exploring the town. Vaude expanded on this idea of extra top-loading space with their Karakorum Pannier Set, which integrates both panniers and trunk bag into one bike bag. This hybrid approach includes an innovative top section that can be zipped off and used as a backpack.


Trunk bags also come in handy when traveling with your bike, and using public transit. Rack-top cases look professional, are easily removable, and are designed in the style of a suitcase. These travel-style trunk bags make it possible to ride up to the gate, check a bike, and carry on the case as standard luggage. Small details like outer mesh pockets for putting shoes, lockable zippers, internal organization for clothes, and telescoping push handles make rack top cases ideal for the biking professional or traveling bike enthusiast.

Mountain bikers aren’t left out. Vaude has made a trunk bag that attaches directly to the seat post, so eyelet racks aren’t necessary to set up your mountain bike with cargo capacity. Available in different sizes, these seat post mounted trunk bags integrate the bag and rack together as one piece. Made for small mountain bike excursions, or traveling ultra light. Carrying the necessities on your bike instead of on your back makes skirting over those baby heads much more enjoyable.

Bike Trunk Bag Styles:

  • Rack-Top Bags: Traditional rack-top bags such as those by Lone Peak have been used by cyclists for decades and are by far the most common and recognizable bike bags, perhaps even more so than bike panniers. Great as a first cycling bag, this style of trunk bag is useful for bike commuting, errands and adding basic cargo capacity to a bicycle. Over the years, features such as drop-down panniers, locks and integrated mounting systems have added to the utility and appeal of this abundantly useful style of bicycle bag.
  • Rack-Top Cases: These cases are a newer addition to the trunk bag genera. Made to look professional off the bike, while still offering durability on the bike, Rack-top cases are the double agent of trunk bags. They usually include places to put a change of clothes, a netting pocket for shoes, and sleeves for legal sized documents.
  • Rack Packs: A roll-top, waterproof bag geared for touring. Ortlieb offers four sizes: S, M, L, XL. We find the Medium Rack Pack to be the most useful size for touring. A good in-between size for fitting bulky items like a tent and sleeping bag.
  • Seat Post Mounted Bags: This setup is an excellent solution when the benefits of a trunk bag are sought after without the requirement of mounting a bike rack. Limitations of this style include limited weight capacity and the inherent inability to increase capacity by adding bike panniers into the mix.


Methods for Mounting Trunk Bags to Your Bike:

  • Rack-top/Strap Mounted: The most common method for mounting a bike trunk bag is to the top of a rack, utilizing the variety of straps built onto the bag. Both Lone Peak and Vaude Rack-Top Bags have Velcro straps that fasten securely to the rack.
  • Rack-top/Integrated Mounting: Some rack-top bags, are designed to integrate with a specific rack and have interfaces on the bottom for attaching to these racks. Most of these mounting systems are only compatible with racks which include the integration system.
  • Rack-top/Mounting System: Some rack top bags are designed to work with a rack attachment system similar to the above mentioned rack integrated systems, however these systems offer a separated piece that can be mounted to a bike rack. This allows the system to be more universal, working with most any bike rack. The Ortlieb lineup of rack-top bags and cases utilizes this type of system with the E159 Rack-Top Bag Mounting Set. The Ortlieb Rack Top Bags can easily work with multiple bikes by installing the E159 system onto each bike rack. The mounting set also offers a convenient lower rail for hanging panniers so they will not interfere with the removal of the trunk bag.
  • Seat Post Mounted: This system allows the trunk bag to be used without a standard rear rack. The rack portion of the bag is clamped to the bicycle’s seatpost. Most seatpost mounted bags, such as those by Vaude , can be removed with a push of a button, separating off the front portion of the rack’s seatpost mounting clamp, allowing the bag to be removed for off the bike activities.
  • Pannier Mounted: Bike trunk bags that are intended to add additional capacity to rear pannier setups often utilize the panniers for mounting. The Ortlieb Medium Rack Pack is best mounted by running its end buckles through the handles of the Ortlieb Panniers. A strap or bungee, such as the Tubus/Racktime Rack Straps, is then run over the center of the bag and clipped to the front and rear of the rack.


Features to consider:

  • Side pockets and top bungees: These features are great for organization. The question is, in what kind of weather you will be riding. Zippers and pockets, and bungees are what you’ll want for a sunny forecast, but reach for an all-weather Ortlieb bag when the clouds start rolling in.
  • Drop-down Panniers: An instant solution for adding cargo space. Bags like the Vaude Silk Road Plus offer drop-down panniers which zip into the side pockets when they are not needed. A compact way to travel, when that quick trip to the grocery store turns into an unexpected shopping spree.
  • Use off of the bike: Most trunk bags include a carrying handle, shoulder strap, or both. The convenient location of rack top bags makes it a natural transition to carry your bag with a messenger style shoulder strap, or lunch-pail style with the top handle.
  • Rain Protection: All of the Ortlieb trunk bags protect against most any weather condition, but if you’re looking for something a little less burly, or you don’t need full weather protection, the Vaude, Lone Peak, or Racktime bags are good options. With outer pockets and more internal organization, these water resistant bags have rain cover options for those unexpected showers.
  • Size and Capacity: From the small Racktime TrunkIt Front bag to the Ortlieb XL Rack Pack, there are a multitude of different size trunk bag options available for everything in between. Keep in mind that rack top bags are made to carry lighter items. As the weight of the bag increases, so does the center of gravity, which can make your rig unstable. The typical rule of thumb is to pack heavy objects as low as possible, and have a fairly balanced load from left to right, and from front to back. This comes more into play with a heavy touring setup more than with a standard lightweight commuting set up.


Vaude : Vaude offers both rack-top bags and the innovative seatpost mounted bags. Vaude’s range of rack-top bag includes the basic Silk Road II, the roomier Silk Road Plus with drop-down panniers and the voluminous Karakorum integrated pannier, rack-top bag and backpack system. The Vaude Offroad seat post mounted bags are geared towards light-weight day trips on more aggressive terrain. The Offroad bags offer a quick solution to adding carrying capacity without having to deal with mounting a rack to your suspension mountain bike.

Ortlieb : Ortlieb offers fully functional, completely waterproof rack-top bags and cases with a bomb-proof design. The Ortlieb Rack Packs are best used for storing light, bulky items, and are a great choice for increasing capacity on your bike touring rig. For travel and commuting, Ortlieb brought the rack top bags and cases to their lineup. The bags have all of the tough Ortlieb outer components for weather protection, but with added features like internal organization, locking zippers, and an included mounting system.