Biketest: Cairn E-Adventure 1.0

Ignore that huge down tube and Cairn’s E-Adventure 1.0 could pass as a regular gravel bike. It has gravel-dedicated tubeless-compatible wheels, a SRAM 1× transmission and hydraulic brakes, and the stable geometry of a machine designed for loose surfaces.

But that down tube is hard to ignore. It’s massive because it houses the e-bike’s Fazua Evation power pack. This comprises a 250Wh battery and the drive motor, which are contained in one removable cartridge. The drive pack must be removed to turn the battery on (and off) and to recharge it, so the pack’s lock and switch get plenty of usage. Those on our well-used test mule were baggy and notchy.

With the 3.3kg drive pack removed, the bike can be pedalled normally. There’s a replacement cover for the down tube available; without it the motor coupling with the bottom bracket gear box is left exposed to dirt. Most E-Adventure owners  will surely prefer to ride with assistance all the time, not least because it is very effective. Cairn quote 250W in middle ‘River’ mode, with a surge of up to 400W available in ‘Rocket’ setting. These and the lowest ‘Breeze’ assist level are selected via a pad on the down tube.

So, drive pack removed, battery turned on, pack replaced, Rocket mode selected – and away we go. Straight up a nearby 1-in-3 rocky track, which the bike handled with ease. That 400W max is entirely believable. Battery life is likely to be short at this setting and the motor was hot by the top. It whined a bit too.

The motor’s control software, which senses cadence, pedal pressure, and speed, moderates power delivery so it tails off rather than stopping abruptly. Shifting on a steep climb thus results in a gear crunch as the motor continues to drive  after pedalling ceases. There’s an app to track various parameters, and the whole thing is great fun if, perhaps, not as slick overall as the main opposition.

Verdict

Powerful and sensitive removable drive system (which needs removal prior to each time it is to be used), in a competent, well-equipped gravel bike chassis.

Other options

Orbea Gain M20 £3,999

Well-equipped, lightweight, road-orientated, ebikemotion X35-powered e-bike with clearance for wider tyres. 

Boardman ADV 8.9E £2,699

Fazua-powered all-rounder with crisp styling and impressive specification for the price.