Our pal and world bike wanderer and writer Cass Gilbert borrowed an Extrawheel Voyager from us for a bit. If anyone knows touring gear, it is Cass. 
Check his great photography and writing about his adventures and favorite gear at his blog While Out Riding. So without further ado here is Cass…
Extrawheel Voyager
A rear rack and pannier setup, supplemented with a bar bag up front, is probably the ideal setup for most tours. But there are times when a trailer comes in handy too, particularly for off-road exploration, where conditions are more demanding on your bicycle and its wheels.
As someone who enjoys the challenges of finding remote, dirt road routes across the world, the Extrawheel appeals in two ways.
Like all trailers, it shifts weight "“ and thus wear and tear – away from your bike. This opens up the opportunity off running a lighter setup than a traditional touring bike, without fretting over all important tyres and wheels. If you enjoy mountain biking side trips as part of a longer tour, this works particularly well.
Unlike other brands, its 26in or 700c wheel also serves perfectly as a spare, in far flung parts of the planet where a replacement would be hard to find. Granted a failed rim is an unlikely, worst case scenario. But the longer and more remote the tour, the more opportunity there is for a mechanical failure. This is particularly beneficial if you tour on 700c rims, which are all but impossible to find outside of the US, Europe and Australasia.
The Ride
Overall, the Extrawheel handles well. There's little side to side tug when riding out of the saddle, it tracks neatly behind the bike, and its big wheel skips confidently over rocks and roots. Panniers make access to cargo straightforward, though it's worth packing weight low and evenly, as this impacts the way the trailer handles. Similarly, I found a small amount of weight on the handlebars, like a bar bag, helps to stabilize steering. Without this, I experienced some low-frequency wobbles when pedaling.
On steep, loose climb, it pays to concentrate on keeping the back of the bike weighted, to stop the rear wheel slipping out. As with most trailers, the Voyager suits sitting and spinning, rather than honking dramatically from side to side.
The sprung fork hitch system is simple to use – no fiddly retention pins are necessary. Despite appearances, I never had it disconnect even over even the roughest of terrain.
The Extrawheel also benefits from being considerably more compact than many single wheel trailers, making it easier to weave around town "“ and deal with off the bike.
The trailer is rated to a massive 30kg in payload. For day to day touring I wouldn't burden it with anything like that amount, especially if heading off road. But it's good to know the capability is there if you really need it "“ for hauling extra water, for instance.
I should add that like most trailers, the Extrawheel takes some time getting used to. After a couple of outings, it's starts to feel more comfortable and predictable "“ as you react and adapt to its quirks.
Pros:
The Extrawheel moves weight away from your bike, decreasing wear and tear on your wheels and tyres. Similarly, running three wheels allows you to rotate tyres more often (it's the back tyre on your bike that takes the brunt of the action), so you can eek more life out of them.
At 3.6kg as tested with a 29er wheel, it's light "“ and you can offset the need to carry a spare tyre and a rear rack, bringing it down to around 2.3kg. It's simple too "“ there's not a lot to go wrong.
The big wheel rolls well over obstacles and doesn't hook up on on curbs as smaller wheels are prone to do.
It will fit any bicycle, without the need to make any modifications for loaded touring.
It's compact enough that the turning circle is tight and it won't get in the way too much. The Extrawheel’s easy to load on a train or bus, or store in a guesthouse.
The trailer can be broken down in size and stashed in a bag. With a big enough bike box, there should be room for a third wheel in there too.
Carrying a spare wheel could get you out of a fix when you most need it"¦
Cons:
Despite all the extra hardware, the Voyager only actually provides two large panniers worth of space "“ 40-50L "“ compared to other more capacious trailers, which typically offer 80L. If this isn't enough, you'll still need to run a rack on your bike too.
The load's positioned relatively low, which is worth taking into account if you're planning a rocky, rutted tours. This may affect pannier choice too, as some are shaped deeper than others.
Tents with longer poles don't always fit in panniers. Unlike a traditional rear rack and panniers, there's no platform to strap a tent to, so you may need Extrawheel’s ‘top rack‘ too.
If loaded to its full rated capacity "“ 30kg "“ it can adversely affect steering. I wouldn't recommend it with that kind of payload if you're riding challenging off road terrain.
Unlike many other single wheel trailers, the Extrawheel doesn't double up well for utility uses back home "“ after all, it's effectively the same as carrying two of panniers on a rear rack. Trailers with a larger loading bay are more versatile, and easier to pack too.
Spec:
Typically, the Extrawheel weighs under 4kg, depending on the wheel/tyre combo you run. You can offset the need to carry a spare tyre against this "“ knocking off an extra 500-800g, and potentially a rear rack on your bike "“ another 700g. This puts it at about 2.3kg heavier than the equivalent rack and pannier setup.
There are 3 fork mounts to choose from, accommodating 26in, 29er or "˜snow' tyres. The 29er fork has room for "˜standard' 700c tyres and mudguards.
The Extrawheel uses a 130mm space hub, the same as your front wheel.
There's all kinds of fork/wheel/mudguard/pannier combinations you can choose from, so you only need buy what works for you. For longer tours, I'd recommend sourcing your own wheel, with the same hub/rim/spoke combo as your bike for versatility.
Final Thoughts:
For a trailer, the Voyager’s load capacity is limited "“ in many cases, it makes more sense to simply fit a rear rack and panniers, especially for more road-orientated touring, or for those who pack light. As compact as it is compared to other trailers, it's still an extra piece of hardware to deal with, for a relatively small amount of added capacity.
This said, the Extrawheel moves valuable weight away from the rear wheel, without the weight penalty incurred by many other trailers. If you enjoy mountain biking as much as touring, it offers the opportunity of travelling with a light bike that's fun to ride "“ which is particularly welcome on singletrack side trips. For anyone touring with 700c wheels, there's also the warm, peace-of-mind feeling of knowing you're self sufficient, wherever you are in the world.
For real expedition types, the Extrawheel also adds capacity on those remote, long distance tours "“ again, spreading heavy cargo over a third wheel "“ and giving you the option of running a suspension fork without needing to load it with weight. Seeing as you're going to the trouble of pulling a trailer, it makes great sense that you can cannibalize parts of it too.
Lastly, I can see the Extrawheel's compact length working particularly well for tandem tours, where space can be a real premium. I bumped into a couple touring with one in Ecuador, who'd chosen it for that very reason.
