Best Seat Packs for Bikepacking

by Stan Purdum

Bikepacking is self-supported bicycle touring off-road and in the back country where traditional panniers and tag-along trailers have been replaced by packs that attach to the bike without racks and maintain a narrow profile to avoid snagging on trailside vegetation. Typically, bikepackers rely on handlebar packs, frame packs, seat packs and smaller peripheral packs.

Here is a round up of some popular seat packs, which should not be confused with the small, under-the-saddle wedge bags many of us use on daily rides to carry a patch kit, spare tube and a multi-tool.

Bikepacking seat packs are much larger bags designed to carry gear for a multi-day adventure. They attach to the saddle rails and seat post and extend back behind the saddle and usually slightly upward for several inches. Because of their size and location, they effectively also serve as rear fender.

These bags are waterproof and designed with enough internal support to hold their shape and not sag, and with sufficient strapping not to wag side-to-side while the bike is in motion. Most also have reflective features to enhance visibility.

For this roundup, I’ve selected the biggest seat packs offered by the various manufacturers. Most also offers smaller packs with similar features should you not need the large-capacity bags. These large bags, however, can be rolled down and compressed when carrying smaller loads.

NOTE: All the bags require a specified minimum space between the saddle rails and the rear tire, so if you are a short rider or run your bike without much seat post exposed, be sure to check what the minimum is for the bag you like.

Ortlieb Seat-Pack 16.5L

The 16.5L Seat-Pack from Ortlieb is one of the biggest such bags on the market, but it doesn’t have to be used at full size, so it offers a lot of flexibility. Thanks to its roll closure and adjustable straps, your load in this one-piece, waterproof bag can range from as little as 8 to as much as 16.5 liters. What’s more, the pack has a nifty air valve on the non-drive side that permits maximum compression of the contents to keep the bag tidy (This video shows how the bag mounts and how the air valve works.)

A lattice-laced shock cord on the top side of the pack enables you to stash items like jackets you may put on and take off during the day. Because the bag has a conical shape, with the narrow end being the part under the seat, the Seat-Pack reduces the likelihood of thigh rub while pedaling. The pack boasts four 3M Scotchlite reflectors to accommodate various roll volumes, and it comes with a five-year warranty.

Ortlieb is a German company founded in 1982 and has been a leader in making waterproof panniers for on-road bike touring. With the introduction of the Seat-Pack 16.5L, it’s now doing the same for off-road cyclists.

https://ortliebusa.com/product/seat-pack/

See it on Amazon.

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Revelate Terrapin System 14L Seat Pack, $155

This is a two-piece unit — hence the “system” in the Revelate Terrapin System 14L. The first piece is a harness that attaches to the seat post and seat rails to form a stable, cave-like pocket into which the second piece, the 14-liter waterproof dry bag, is inserted and cinched down tightly. The “floor” of the cave is a sturdy plastic that protects the bottom of the bag like a fender. When fully loaded, less than half of the dry bag protrudes to the rear beyond the harness. The cinch strap locations virtually eliminate side-to-side bag sway. The dry bag has a purge valve to allow compression when packing. An external webbing and loop system provide additional storage on the outside of the bag. No time limit on the warranty, but the company is very specific about what is and what isn’t covered by it.

Revelate is an Alaska-based business formed by bicycle adventurer Eric Parsons who learned through direct experience that bags and tag-along trailers made for road touring don’t work well in the back country. See Revelate’s story here. All their bags are made in the USA.

IMPORTANT NOTE: As of this writing, Revelate has a recall on versions of the Terrapin System 14L bag sold from December 2018 until April 2019. That bag is easily identified by a pair of hooks on the top rear of the bag. The problem is fixed on sales going forward, and Revelate will also fix all of the recalled ones at no cost to the purchaser. See details of the recall and how to get yours fixed if you have an affected version can be found here. (https://www.revelatedesigns.com/site/warranty-return/terrapin-recall/)

https://www.revelatedesigns.com/index.cfm/store.catalog/seat-bags/TerrapinSystem14L

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Blackburn Outpost Elite Universal Seat Pack and Dry Bag, $180

Like the Revelate Terrapin System, this Blackburn bag is a two-piece unit — harness and dry bag — but unlike the Revelate, the Blackburn will also work with both standard and dropper seat posts. The waterproof dry bag has a 10.5-liter capacity and is equipped with a scuba-style air bleed valve to assist with compression while packing it. The bag has an external lattice-laced elastic cord for quick storage of items outside of the bag. See a video about features and installation here. The bag has a two-year limited warranty.

Blackburn was founded in 1975 by Jim Blackburn to make a range of accessories to serve the then-emerging cycling culture. The company is based in California. It doesn’t make a big deal about its history, but this 2014 article in BikeRumor tells some of Blackburn’s story.

https://www.blackburndesign.com/p/outpost-elite-universal-bike-seat-pack-dry-bag

See it on Amazon. https://amzn.to/32kHs1J

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Topeak Backloader 15L Seat Pack

This 15-liter bag is a two-piece unit, but different from the other two-piecers in this list. Rather than being a harness-and-dry-bag combo, it’s a bag within a bag. The outer pack is a complete bag with hook-and-loop fasteners on the outside for external storage, but it’s water resistant rather than waterproof. The inner bag is waterproof. Some reviewers say this pack wobbles side to side a bit more than some other bags. It has a two-year limited warranty.

Based in Taiwan, Topeak designs, manufactures and retails bicycles and bicycling equipment worldwide.

https://www.topeak.com/global/en/products/bikepacking-series/969-backloader

See it on Amazon: https://amzn.to/2PPVDJi

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Rapha Rear Pack 15L, $130

The Rear Pack is a two-part unit comprised of a waterproof dry bag and a rigid harness. A downward-facing valve on the dry bag lets air out and enables you to roll the bag down small when not filled to its maximum 15-liter capacity. The bag narrows gradually for a secure fit inside the harness, which is attached to the seat post with a durable Velcro strap and to the saddle rails with two reinforced straps. An aluminum spine combines with a three-point strap system to cinch the upper and lower section of the harness together, though some users say the straps are bulky and difficult to pass through the cams locks. Bag is stable on rides, reviewers say, and has a highly reflective finish for visibility on the road. Unlike most other seat packs, this one does not include any outside webbing or bungee cord setup for exterior storage. It does not work with a dropper seat post. Rapha Classics products come with a 30 day no-quibble riding guarantee.

Rapha was founded in London in 2004. The name Rapha was taken from the 1960s cycling team Rapha, which was named after the apéritif drink company Saint Raphaël. The company has developed an international cycling club, which gives members access to exclusive club apparel and high-end bike rentals. The Rapha Cycling Club hosts rides and events at stores known as Clubhouses in 23 international locations throughout the United States, Europe, Asia and Australia.

https://www.rapha.cc/us/en_US/shop/waterproof-rear-pack/product/BSD01XX

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Arkel Seatpacker 15 Bikepacking Seat Bag, $230

This is a one-piece bag, but attaches to the bike by means of 1) an aluminum hanger that slips into a sleeve on the top of the pack and 2) a quick release strap that goes around the seat post, making the bag as easy to attach and remove as is a dry bag from a harness. The hanger itself, which virtually eliminates tag wag, attaches securely under the saddle and is also quickly removable. See a video of the whole setup here. The bag is waterproof and has a sealed liner. While there’s no outside webbing, the bag does have a zippered pocket on the top where your phone, wallet or other small items may be stored. The Seatpacker 15 works with both standard and dropper seat posts and comes with a lifetime warranty.

Arkel is a Canadian company, founded in 1988, and based in Quebec. In addition to employing talented designers and seamstresses, the company works with a social-service program for people with intellectual disabilities and pervasive development disorders who do the final assembling and put the finishing touches on several of the company’s products.

https://www.arkel-od.com/seatpacker-15-bikepacking-seat-bag/