Review: Specialized Fuel Cell, Reserve Rack, Air Tool

The Specialized Fuel Cell is a Shiv specific storage system designed to mate perfectly to the frame and not add any frontal area to the bike. Specialized goes so far as to say that its design reduces drag. This would make it possibly the ideal storage system for the Shiv, and as such it has been something that I wanted to get my hands on ever since it was announced.

The product consists of 3 parts: a mount, the main hard storage compartment, and a soft rubber cap. The mount attaches to the bottle bosses on the seat tube, and allows for quick and easy removal of the Fuel Cell. The top cap has a small compartment designed to provide easy access to Gels and nutrition while riding. Tools and spare parts that aren't regularly needed can be stashed away in the main hard storage compartment, which can only be accessed after removing the rubber cap.

I found the weight of the product to be minimal and a decent tradeoff for the added storage. Crosswind handling didn't substantially change after installing the Fuel Cell. I also like the look of the Fuel Cell, but some people seem to hate it. This seems to be very subjective.


I really like the way Specialized designed the mount, as it allows one to remove the Fuel Cell to load up with parts and nutrition. This is much easier than if the main storage compartment had mounted directly to the frame.

The main storage compartment is where one will store the bulk of their spare parts. It feels a lot narrower than I was expecting, but it has to be narrow in order to not add frontal area to the bike. This won't be an issue for most people as it is wide enough to easily hold tubes and CO2 cartridges. What will be an issue, however, is how short the main storage compartment is. When I first went to load it, I actually thought it was the perfect size as all my parts fit just fine. My excitement was short lived, however, as I realized that the rubber top cap had to sit inside of the main storage compartment as well, and that meant most of my spare parts would have to be removed. I tried to force the rubber top cap into position, and was able to get it into place with a little pressure (compressing my tube in the process), but as soon as I let go, the top cap popped right off.

This brings me to my main gripe with the Fuel Cell. The top cap has no active retention mechanism. There is no lock or latch to keep it in place. It just uses a friction to sit on top of the main storage compartment. If you compress the items in the main storage compartment at all, they will eventually push the top cap off once you release your hand. The top cap also has a way of working loose as you ride and the items in the main compartment bounce and wiggle around.

This problem was so bad that I found myself checking the top cap every 5 minutes during my rides to ensure that it was still there, but still wound up losing it on a training ride. After losing the top cap, I used electrical tape to cover the top of the Fuel Cell for Ironman Boulder. I actually came to prefer this to the rubber top cap as I was able to cram more stuff into the main compartment. I contacted Specialized about replacing the top cap, and they were friendly and sent out a replacement for free, but I am still undecided about whether I will use the top cap at all, or just keep riding with the electrical tape.

A bit of searching on the internet brings up some solutions to the top cap issue. Pro triathlete Erik Linkemann uses clear plastic tape to hold the top cap in place. Kevin Taddonio uses a marker to draw a line indicating the depth of the rubber cap, and doesn't cross this line when filling the Fuel Cell. He made a video to show people struggling with the Fuel Cell how he loads it.

What it will hold

Due to the limited size of the main compartment, you have to really minimize the amount of parts you carry to make it all fit. I tend to be more of a pack rat, and carry everything I might need. My flat kit consists of the following:

  • Spare tube (Q Tubes w/ 80mm valve stem)
  • 2 CO2 Cartridges
  • Inflator head
  • 2 Tire levers
  • Smallest multi tool I could find
  • Master Link

I used to keep all of these items in the smallest saddle bag I could find. That worked, but in terms of aerodynamics wasn't the best solution. I had hoped that I could fit everything in the Fuel Cell, but there is not nearly enough room for it all.

One could put some of their spare parts in the top cap. The added weight would probably help keep it from coming off, but you would lose the ability to store gels in this location. Or you might cut a hole in the top cap to make the main cavity larger, but you would also lose the ability to easily access gels, and might still have issues with the top cap coming off. With both of these solutions, I would have some concern about parts coming out of the top cap. The top cap has an open slit at the top that was designed to keep lightweight gels in place while providing easy access while riding. I doubt it would keep heavier tools in place, but I have yet to try.

In a video that Specialized posted, Mark Cote showed how he setup his Shiv for IM New Zealand. He had a spare tube and tire lever in the Fuel Cell, and then put his CO2, inflator head, and pit stop on the reserve rack behind his saddle.

I think this is how Specialized envisions that the Fuel Cell will be used. One would keep a tube and tire lever in the Fuel Cell, along with some gels in the Fuel Cell's top cap. Then CO2, an inflator head, and extra gels would be stored elsewhere on the bike or in a jersey pocket. If you are OK with this type of setup, the Fuel Cell will work well for you. But if you are unable to store CO2 elsewhere on the bike, or are looking for one storage container to hold all your parts, the Fuel Cell will definitely not meet your needs.

I made a video showing what my Fuel Cell will hold, and comparing it to my old saddle bag:


The Fuel Cell is probably the most aerodynamic way to store spare parts and nutrition on your Shiv. If it will hold everything that you need, it is a no-brainer. But for those that wish to carry additional items, or want to store everything in one place, the Fuel Cell will not be a good choice. The rubber top is held in place by friction, and may come off if you overload the Fuel Cell or if the contents of the Fuel Cell push up on it while riding. Had there been some sort of active retention mechanism, the Fuel Cell would probably be able to hold a lot more stuff. I really wanted to like this product, but it doesn't suit my personal needs very well. I don't use any gels (liquid only), and carry a large parts kit. And while the product doesn't work well for me, it might be a good fit for you, but you will want to make sure it meets your storage needs before purchase.