Porcelain Rocket Mr. Fusion V2: 5,000 Mile Review

This seat pack has seen a lot. After 5,000 miles and some tough love, it’s time to give the Porcelain Rocket Mr. Fusion V2 the long-haul review it deserves…

To be clear, we’ve actually tested three Porcelain Rocket Mr. Fusion V2 seat packs: a pre-production sample, the gently used blue one, and the high mileage green that’s shown in most of these photos. By gross estimate, it has about 5,000 miles on it—hard miles on the Trans-Uganda, the Congo Nile Trail, the Altravesur, as well many other routes in the US including the TNGA. It’s been used on five different bikes. It’s had a wide assortment of stuff strapped to it, including shoes, papaya, firewood, jackets, a bottle of wine, and Spanish pastries. It has grease stains, and the logo is bleached white from hundreds of hours under the equatorial sun. It’s survived falls and being tossed around on a bus. It’s been grabbed and pushed by hundreds of Ugandan children. It’s been packed and unpacked countless times. To say that it’s been thoroughly tested is putting it mildly.

Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
Bikepacking Pack List and Gear

Rack the boat.

Before we dig into how well it fared, here’s a little background. The Mr. Fusion is a different kind of seat pack. Unlike others currently on the market, it is designed around a minimal rack structure. Purists might question the use of a rack for a bikepacking style ‘soft’ seat pack. Doesn’t a rack just add unnecessary weight and bulk? To answer that simply… No. The system offers benefits that far outweigh any extra heft, which is actually negligible due to the thoughtful design.

The idea behind this unique system was initially conceived in August of 2013 while Scott Felter, Porcelain Rocket’s ringleader, was fatpacking the Canning Stock Route in Australia. According to Scott,

The concept came from the frustration of packing things into a seatpack while it was strapped to a bike. A rigid strut made a lot of sense as a support for a quick-release, pack-off-the-bike system. It also made heavier, odd loads more practical on the rear of the bike.”

The mini-rack consists of a CNC machined aluminum seatpost collar bracket that slides onto the seatpost. The brackets are available in three sizes (27.2, 30.9, and 31.6mm). This clamp houses a stainless steel thru-bolt that anchors the 4130 chromoly loop support that is crafted by Hunter Cycles in Santa Cruz, CA. To carry the load, the lower harness (aka “gear saddle”) is stretched over the loop support as tight as a drum. The gear saddle acts as the lower portion of the harness with three compression straps (two on the side and one at the rear) and the male acetyl buckle ends.

Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2 Long Term Review

What’s New?

The new Mr. Fusion (V2) utilizes a similar lower rack and saddle structure as the original design. The chromoly support got a little bend in its profile, which helps cradles the load, as well as a new gray paint job. The top harness and bag itself have been completely redesigned. The upper harness on the original Mr. Fusion system was made of a single piece of fabric and two side straps that connected to the rack saddle. A rear strap held the bag in place. The stitched X-Pac roll-top bag slid into the system and had to be attached directly to the seatpost with an integrated front velcro strap.

The first pic taken of Scott’s original design of the Mr. Fusion. Below (from left): Cass Gilbert’s early prototype, somewhere in South America; Gin showing off her PR bags; The a later version of the V1 shown next to the Revelate Terrapin.
  • porcelain-rocket-mr-fusion-v2-review-42
  • porcelain-rocket-mr-fusion-v2-review-44
  • porcelain-rocket-mr-fusion-v2-review-43

Now, with the switch to a dry bag and a fully redesigned harness, it’s much easier to slide the bag in and out of the rack. The upper part of the harness has two reinforced side panels which are made up of HDPE plastic sandwiched between two layers of 500 denier Cordura. The panels taper at the front and serve to contain the load and create the streamlined shape of the pack. Each is stitched to a burly Rhinotek panel at the top and front. A webbing strap that is bartacked to the top holds the female acetyl clip ends that thread through the seat rails and buckle to the straps on the lower rack ‘gear saddle’. Two compression straps hug the sides and work with the HDPE to shape the load. Then, a single compression strap battens down the rear of the bag.

Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness
  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion compared to Revelate Terrapin

Wag Proof. Sag Resistant.

It turns out that a lot of benefits can be packed into a small rack. Not only does it make packing a lot easier, it has a few hidden perks. When it was released in 2014, Mr. F was universally received as the perfect solution to what bothers a lot of bikepackers… ‘tail wag’, or a soft seat bag’s tendency to move back and forth due to instability. Scott’s response:

Honestly, stability was not really what sparked the idea. Stability was just a happy casualty of the design.”

  • Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
Porcelain Rocket Mr. Fusion V2

No matter the intent. With a simple two-piece rack system at its heart, the Mr. Fusion combines the stability of a traditional rack with the low profile design of a modern seat pack. And, all of that comes in at an unbelievably low weight burden. With the rack, seatpost clamp, and upper/lower harness weighing only 370 grams, the weight of the entire system is comparable, and even lighter than other seat packs in the fully waterproof category. The total weight of the Mr. Fusion V2 system is right at 453 grams (16oz), while the Revelate Terrapin weighs 496 grams (17.5oz) and the new Ortlieb Seat Pack is 430 grams (15.2oz).

In contrast to fully soft bags, which tend to sag when heavier contents are added toward the rear of the bag, the Mr. Fusion can be loaded without overthinking weight distribution. The strut supports almost the entire length of the bag.

Lightweight, load stabilizing performance aside, one of my favorite things about the V2 is its unintentional capability of carrying some odd-ball items. This is especially beneficial on long trips when having a little extra space is key. While bikepacking in Africa this past winter, we strapped our spare tubes to the rack using electrical tape. You can also place flat items within the harness under the drybag, such as as a ground cloth for the tent or a tarp. Also, with its slender size and added support, it’s possible to strap things to the sides and top, such as a pair of Crocs.

Porcelain Rocket Mr. Fusion V2 Review
  • Porcelain Rocket Mr. Fusion V2
  • Porcelain Rocket Mr. Fusion V2 Long Term Review
  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness

Fully Waterproof.

The dry bag itself was a major advance in the Mr. Fusion V2 system. It’s 100% waterproof, whereas the X-Pac version on the original was only water resistant—a big difference when you are carrying clothing, a down sleeping bag, or electronics. Even when seam-sealed, most fabrics, X-Pac included, can ‘wet out’ with enough rain and wick water to the interior of the bag. According to Scott:

Building a system that was 100% waterproof was always the final objective, but due to the need to outsource RF-welding, it took until V2 to realize that. As the system progressed through prototyping, I was pleased that weight could still be kept minimal while still incorporating all of the important features I was looking for in a seat system.”

To solve this, the V2 was built around a Radio Frequency (RF) welded air-tight drybag. RF welding is a technology that uses electromagnetic energy to join waterproof fabrics and eliminate the need for stitching, which creates points where water may enter. The drybag is constructed out of 210 denier polyurethane coated nylon fabric. It doesn’t feel quite as rugged as materials used on other fully waterproof bags, but it held up fairly well over 5,000+ miles of abuse. Although it is showing only a couple pinholes from thorns and bushwhacking. While a slightly thicker fabric would be a welcome addition to the Mr. Fusion system, repairing it is easy with an off the shelf repair kit such as Tenacious Tape, easily found at REI, MEC, or any local camping supply store. Right now there aren’t too many fully waterproof seat packs on the market, the aforementioned Revelate Terrapin and Ortlieb being the other two big contenders.

In addition, at 8-13 liters, the Mr. Fusion V2 drybag is the perfect size. By packing lightly and cinching the top and bottom harness, it can take on a narrow girth, which is a nice benefit for use with full suspension bikes. It can also be packed short for lighter loads, or long for bigger trips.

Porcelain Rocket Mr. Fusion V2, bikepacking seat harness
  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness
  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness


  • It’s the most stable seat pack out there, period.
  • As mentioned, the Porcelain Rocket Mr. Fusion V2 can also be packed without mulling over how the weight is distributed, with no sag.
  • It’s a vertically slim pack, so it even works for shorter riders with limited space between the tire and seatpost; it’s really the perfect size, in my opinion.
  • Off the bike unpacking and repacking.
  • Simple harness loading and unloading.
  • The ability to carry other items such as a tent ground sheet or an innertube under the rack.
  • It’s available in an array of colors (black, red, gray, multicam, and multicam black).


  • At first I wasn’t a fan of having the velcro at the end of the drybag, but it eventually grew on me; some might still find it annoying, but ultimately I appreciate that it can be thrown around camp without being rolled, and still keep the bugs out.
  • Another grouch is that the side pull straps could be an inch longer; however, I mentioned this to Scott and it’s already been implemented on the current batch.
  • I wish there was some fuzzy velcro on the driveside harness panel; after a while the seatpost strap curls up as it’s not really anchored.
  • The dry bag doesn’t seem quite as burly as other waterproof seat packs in this class; after a lot of rough use, it developed a couple tiny holes holes (probably thorns or sticks… it’s been through some bushwhacking). It’s an easy repair with Tenacious Tape though, and ultimately, it’s held up through a lot of rugged miles.
  • Weight 16oz (454g)
  • Capacity 5–13 liters
  • Place of Manufacture USA and Canada
  • Price $185.00
  • Contact PorcelainRocket.com

Wrap Up

The obvious benefits of the Mr. Fusion V2 system are clear. It’s one of a few on the market that’s completely waterproof. It’s arguably the most easy to remove for off the bike unpacking and repacking. With the rigid rack and the well designed compression points, there is absolutely zero lateral movement in the system, even on the rough stuff. And it’s also incredibly versatile in the fact that items can be included in the harness or strapped onto the underside of the rack. Some folks might be skeptical of using a rack, as minimal as it may be, with a bikepacking setup. But the Mr. Fusion V2 is just as light as most others on the market and its functionality and minimalistic design should speak to the ultra-endurance crowd, weekend bikepackers, and expedition dirt tourers alike.

We review a lot of seat packs here, and I often get asked, point blank, “So really, which is your favorite?” That’s always a hard question as there are so many great products out there. And, it’s based on opinion. But I can honestly say that out of all the seat packs at my disposal, the Porcelain Rocket Mr. Fusion V2 is the one I reach for most.

  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness
  • Porcelain Rocket Mr. Fusion V2, bikepacking seat harness

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