JPaks DropperPak Review: Exclusive First Look

The JPaks DropperPak has been in development for well over a year, and although JPaks’ owner Joe Tonsager has teased it several times on Instagram, it’s officially available for preorder as of today. I’ve had the DropperPak in my possession for a couple months now, and it’s been on countless day rides, several overnighters, and a few multi-day bikepacking trips. Personally, if I’m riding a route with lots of singletrack and technical terrain, running a dropper post makes a lot of sense. And nine times out of ten, I’d take a dropper post and a rigid fork over a standard seatpost and front suspension. Although I’ve had varying degrees of success with the dropper post seat bags I’ve tested over the past few years, in the end they all allow for mostly normal dropper post functionality, which makes riding a loaded bike easier and more fun.

A Balancing Act

The main predicament with dropper post seat bags is related to their capacity and stability. Too heavily loaded and most dropper posts have a hard time returning back to their regular position. Too small and it becomes difficult to find enough space on the bike for all the gear needed for bikepacking, which often means incorporating a backpack or large handlebar bag setup into the mix.

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The most stable saddle bags—think Porcelain Rocket Mr. Fusion—rely on some kind of rigid seatpost support to limit sway and bounce while riding off road. Since dropper posts lengths and designs vary, bag manufacturers have developed creative ways to keep things stable without interfering with the normal up and down movement of the post. Most manufacturers were inspired by the world’s first dropper post saddle bag, the Porcelain Rocket Albert, using some variation of saddle rail supports to keep things sturdy. The one issue with these types of bags is that they have the ability to keep larger loads stable, but when packed full can overwhelm normal dropper post function. Finding the right blend of stability, size, and weight is a challenging balancing act for bag makers. Thankfully, there are plenty of great options out there depending on your preferences and needs.

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The JPaks DropperPak addresses stability with an internal double layer HDPE panel and Wolf Tooth Valais mounting system. A pack size of 2 to 5 litres is at the smaller end of the spectrum, but makes sense for a dropper-specific bag, and the entire package weighs just 360g (12.7oz). Although the DropperPak takes design cues from other dropper post seat bags available, its slender shape and clean looks make it stand out. Its thoughtful, pared down design is possibly its greatest strength. For now, the DropperPak is made from a VX-42 spine, LS-21 sides, and a Hypalon reinforced bottom. The internal spine is also stabilized with ⅛” thick HDPE panels on the top and bottom that double up to ¼” thick at the seatpost straps, with additional closed cell foam padding. Although the construction itself isn’t waterproof, it uses waterproof materials and all internal seams are finished with bias tape to create a very weather-resistant bag. I rode through some serious rain on our Powell River Sampler scout, and my sleeping bag and down jacket were dry at the end of the day.

Installing the DropperPak

As mentioned, the DropperPak requires a Wolf Tooth Valais, which is available in both a 25mm and 26mm diameter, depending on your dropper’s stanchion size. The Valais installs by simply stretching open around the dropper post’s stanchion, and then a small bolt and nut tighten it in place. For a proper setup, the Valais should be positioned in its highest position, right at the top of the dropper post. Although this means dropper travel is limited by 25mm due to the size of the Valais, it’s a huge bonus that JPaks designed it in a way so the DropperPak makes the most out of what dropper travel is available. A large and grippy lower strap cinches down around the Valais and secures back onto the bag via a large section of velcro.

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All that’s left is to weave the two side straps / buckles through the saddle rails and back down towards the bag, where they clip in and lock in place. Setup is quick and straightforward, and I appreciate how easy it is to remove the entire system if I’m switching bikes. Although I normally prefer a seat bag with a harness system and removable drybag, it was nice being able to install and remove the DropperPak so effortlessly. At first I wasn’t sure how to properly adjust the side straps, but quickly realized the velcro tabs need to be detached before making any adjustments to get a proper grip, then the webbing is folded back on itself for a clean setup. I think these straps are best left tensioned and buckles locked, rather than fiddling with the little velcro straps during a trip, unless completely necessary. There’s not much to say about the little shock-cord lattice on the top of the bag, but it’s handy to have the option to dry out some socks or to bring a baguette to camp.

On The Trail

One of the DropperPak’s best features is its minimal clearance requirement and the position in which it mounts onto the dropper post itself. It only requires 6” of clearance between the saddle rails and the top of the rear tire, which is right on par with the Revelate Designs Vole, making it a great option for those riding small bikes with big tires. As an example, my partner Emily used the DropperPak on a few occasions and was able to get full dropper movement on her small Jamis Dragonfly with 26 x 3” tires. On my large frame, I of course also had ample clearance and was never once worried about rubbing. In reality, with the Valais mounted as high as possible on the seatpost, the bag only comes down 5” from the rails, but it’s nice to have a little buffer just in case.

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Although it’s nice to have uninterrupted dropper post function while bikepacking, a benefit of using a saddle rail mounted system like the Rockgeist Gondola and the retired Porcelain Rocket Albert, with only the minimal amount of travel lost (25mm), I think JPaks’ DropperPak is the next best thing. The design doesn’t rely on any custom stabilizing wings or brackets, just the Wolf Tooth Valais, which is well suited to the rigours of bikepacking and not prone to failure. With the side straps cinched up tight, the DropperPak doesn’t swing around at all and only bounces slightly with a heavy load. The HDPE inserts in the spine of the bag do a good job at holding its shape, which tapers in towards the seatpost, and I’ve never had any leg rub while riding.

Although it’s ideal to push the Wolf Tooth Valais up tight against the saddle, those with dropper posts that have an external air valve, like the one on Emily’s PNW Coast Suspension Dropper Post, might consider leaving a little room to avoid unnecessary rubbing. On just one short ride, Emily managed to wear a little hole in the rubberized spine, which I consider user error and not a design flaw. Those with any protruding valves or bolts under the back of their saddle might want to run the Valais a little further down the post to avoid rubbing. There’s also no reason why the DropperPak wouldn’t work on a rigid post, although you’d be losing the added stability offered by the Valais, which plays a big part in the bag’s form and function—but JPaks confirms is does work quite well as long as the post strap is cinched nice and tight.

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• Capacity: 2-5L
• Material: VX-42 / LS-21 / Hypalon
• Weight: 360 grams (including Valais)
• Place of Manufacture: Colorado, USA
• Price: $170 USD (+$15 for Wolf Tooth Valais)
• Manufacturer’s Details: Jpaks.com