For a first attempt at a gravel/e-bike Cairn has done a great job. The E-Adventure manages to retain the feel and ride experience of a 'normal' machine yet will give you a much needed boost when you most require it. It also offers great value in terms of its standard equipment and with the latest update the Fazua motor system promises to be even better.
Reasons to buy
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Geometry and handling inspire confidence
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Fazua motor system provides just enough assistance
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Ability to ride without motor
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Price
Reasons to avoid
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Will you ever ride without the motor/battery?
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The Cairn Cycles E-Adventure 1.0 was selected for an Editor's Choice award in 2020. This year's list contains 78 items which scored a 9 or 10/10 with our tech team - this gear is the best of the best, and has received the Cycling Weekly stamp of approval.
E-road bikes might not be a totally new concept but when Cairn Cycles launched the E-Adventure 1.0 a few months ago its gravel and off-road focus showed an area where electric power could have a real benefit.
Cairn Cycles is an offshoot brand from The Rider Firm and is sibling to, amongst others, Hunt Wheels. With the already established knowledge and understanding for UK riding and rider requirements gathered through its association with these other brands Cairn was able to design a bike able to tackle the terrain most of us are likely to come across. The target was a gravel bike capable of taking on pretty rough terrain but with the versatility that if you want to use it as your daily commuter then it will do that job with aplomb.
The E-Adventure 1.0 has a 6061 aluminium alloy frame designed specifically for this model, and the use of a Faze Evation drive system. Sticking to aluminium has allowed Cairn to keep the E-Adventure 1.0 at a really keen price point and also helps its durability, given how most riders will end up using it.
Cairn has given it some very off-road friendly geometry figures with similar angles, reach and wheelbase measurements to my favoured Cannondale Topstone gravel bike. The E-Adventure 1.0 does have a lower bottom bracket drop for added stability and a shorter fork rake so the steering is going to be bit more responsive. One other feature that Cairn has adopted from mountain bikes is a dropped top tube junction to provide a little more off-road confidence whilst still enabling it to carry a full frame bag.
Cairn has plugged a full carbon fork into the front of the E-Adventure 1.0 to take a bit of the sting out of hitting roots and rocks on a 14 kilogram e-bike. It also features full mounting points for fitting cages/racks to each fork leg and also has internal dynamo routing for long-distance riding.
As to be expected from a bike of this ilk there is a cavernous tyre clearances front and rear. Opt for 65ob wheels and you can fit a 2.25" (57mm) width tyre - proper MTB style. Our test model came with 700c wheels and 42mm width tyres but Cairn claim it will fit up to a 45c on this diameter wheel.
In addition to these features the frame of course has a full complement of bottle cage mounts including dual position down tube eyelets and even one on the top tube. There are also eyelets for a rack and full mudguards.
Motor system
Cairn has opted to design the E-Adventure around the Fazua Evation 1.0. The Evation 1.0 is a very good match for the E-Adventure owing to its lightweight and versatile nature. The entire system (bottom bracket unit, drive pack and battery) weighs 4.6kg - compared to 5.8kg for a Bosch Active Line motor and equivalent battery. What makes the Evation 1.0 more interesting is the ability to drop out the drive pack, battery or both and still ride the bike with zero lost efficiency. The fact this then drops the weight of the bike by up to 3.3kg is also a bonus. Whilst this is a definite plus I'm not sure there are many of us who will truly do this on more than a couple of occasions - why would you not want to have the benefit of the added assistance on tap at all times?
In use the Evation 1.0 is a little different in ride feel to many of its competitors. It still delivers a range of up to 80km, up to a potential 400 watts of assistance and will provide that up to 25km/h. But it delivers the power in a far more subtle way than other systems. It's so subtle that in most settings you don't really feel the system's input until you try riding with it turned off. Even in the maximum 400 watt 'Rocket Mode' it still feels like you are in charge of producing the power, just with an added push. If you're looking at a bike to get you to the top of the steepest hills as fast as possible, you'll need to look elsewhere; this isn't a Strava KOM killer.
It's not perfect either as the power delivery. The model we had on test relies on a pretty narrow cadence range to turn it on - something that has frustrated myself and others. This translates to a pretty jerky power delivery, or distinct drop-off in power, if your pedalling or gear choice suddenly falls outside of optimum.
In this current guise the Evation 1.0 really does bridge the gap between a standard bike and the now expected super-charged e-bike experience. This is a system that puts the onus on you to produce the effort. However, this will change slightly on almost all new Cairn bikes - and other Fazua powered bikes - as Fazua has released it's new Black Pepper firmware update.
The new update - which is available for free via a software update for all existing owners - addresses the seeming lack of power throughout the modes and really gives it a kick without compromising on range in many ways. It also addresses the narrow cadence range and promises to deliver the power in a smoother and more consistent way.
Components
For a bike that has been specced to stay under a price point, Cairn has done a really good job of choosing its finishing kit. SRAM's Rival 11 speed drivetrain is quite clunky in operation compared to Shimano GRX but has solid gear shifts and a very comfortable lever shape for grabbing on rough trails. The gearing is always going to be less important on an e-bike but the 10-42 tooth cassette meshes well with the 42 tooth Praxis chainring; providing a really usable spread of gears.
There is a set of Hunt wheels specced, naturally. Cairn has sensibly opted for the 4 Season Gravel Disc owing to the almost bombproof build. The 28 spokes are laced two-cross front and rear to tubeless ready 25mm wide alloy rims which are perfect for the tyre diameter specced. Our test bike has seen some action from quite a few riders and the wheels are still straight, free of damage and the bearings are still super smooth. Cairn has set up the wheels tubeless and included the excellent WTB Resolute tyre. This tyre offers superb grip in all offroad conditions thanks to its even, square-knobbed tread pattern. It's not the fastest tyre on the road but with an e-bike it doesn't need to be.
Ritchey aluminium handlebar and stem provide a solid if uninspiring looking cockpit setup. The 44cm bar has twelve degrees of flare at the drops so is still pretty subtle and suitable for commuting albeit at the expense of off-road downhill control. Fabric's Scoopsaddle is comfy and well suited to this style of bike. Kalloy's carbon shafted seatpost adds a little extra flex but you can always run a dropper if you fancy something different.
Performance
The E-Adventure 1.0 is an incredibly likeable bike to ride. I can be pretty on the fence when it comes to e-bikes, preferring like many for my legs to be the main performance delivery system for my riding. But after the first ride I came away with the same sense of rewarded effort as if I had ridden a 'normal' gravel bike - but one that I managed to ride farther than my legs felt like they had ridden.
My standard testing area for gravel bikes includes plenty of pretty technical off-road trails as well as wide-open fire roads and of course the occasional tarmac and the E-Adventure 1.0 soon became a favourite for really hammering the twisty stuff. The handling is superb and compared to many gravel bikes that leave you feeling like you're sat teetering precariously above the frame, Cairn's design has you feeling more like you're inside the E-Adventure 1.0. The geometry is confidence inspriring and makes you feel more confident about tackling those tight corners or steeper descents. The additional weight of the bike actually increases handling and grip as well, enabling the WTB tyres to really bite and guarantee your ability to follow a trail and grip on the climbs.
The choice of the Fazua motor system works well with the E-Adventure 1.0 to turn what would be a very competent gravel bike into potentially one of the best mile-munching, all-rounders I have tested. I could see this being equally popular with riders needing a little assistance to keep up with their riding buddies as it would be with riders wanting to be able to extend their bike-packing weekend adventures. In this guise it would certainly transform quite challenging experiences into something a little more enjoyable and achievable, especially when fully-laden.
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James Bracey's career has seen him move from geography teacher, to MBR writer, to Cycling Weekly's senior tech writer and video presenter. He possesses an in-depth knowledge of bicycle mechanics, as well as bike fit and coaching qualifications. Bracey enjoys all manner of cycling, from road to gravel and mountain biking.
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