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, like the Racktime and Ortlieb Bags, can equip a Towney bike with enough capacity for comfortably commuting to work with a lunch, a spare jacket, and other small necessities. Racktime even brought a new design to their lineup in 2010 with the TrunkIt Front bag option. Same idea, different location.
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.