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Genesis Datum 10 review

Genesis Datum review
15 Oct 2015

The Genesis Datum is a fat-tyred carbon road bike that's as fun to ride as it is good-looking.

Cyclist Rating: 
A versatile and surprisingly fast ride
We can't wait to test the hydraulic version

Genesis’s second carbon fibre model piqued our interest as soon as we saw early pictures of it on the brand’s blog. This isn’t touted as a pure gravel bike (although first appearances suggest it would be perfectly at home away from the tarmac) but rather an old-fashioned road bike updated with all the relevant mod cons such as a lightweight carbon frame, large tyre clearance and disc brakes, making it good for any situation. So if the road does come to an abrupt halt when you’re out exploring, there’s no need to turn around – just carry on and see what happens. Chances are the Datum will swallow it all with glee.

Like the test-winning Specialized Diverge we reviewed, the Datum is built around 33mm slick tyres. This size of tyre feels like it could well be the next big thing, and with the widespread adoption of disc brakes, the old limit on tyre sizes (they needed to be thin enough to fit between brake callipers) has been thrown out the window, so there’s little reason fatter tyres couldn’t gain traction. And traction is our favourite thing about these tyres – they stick to the road like glue, making corners brilliant fun, whatever the surface.

Genesis Datum bottom bracket

To create the space for such big tyres, Genesis has used a cyclocross fork, while at the back a cutaway seat tube negates the need for super-long chainstays. Much like an aero road bike, the back of the seat tube is sculpted to create space for the wheel, only here the advantage is good tyre clearance rather than aerodynamics.

One area of geometry that differentiates pro bikes from those for everyday riders is wheelbase. Pro road racers like bikes with a short wheelbase because they let you tuck in tighter behind the guy in front, which is useful when you’re trying to eke out every bit of shelter from the wind in a paceline at 60kmh. It’s less useful, though, when you’re descending unfamiliar hills at high speed on unpredictable surfaces – a short wheelbase can feel skittish. For testing, we tend to choose bikes around size M/54 and we reckon a good wheelbase for a bike that size is 1,000mm. Some race bikes by comparison measure up at 960mm or less. The Datum hits our magic number perfectly, coming in at 1,001mm, balancing high-speed stability with low-speed manoeuvrability. 

Genesis Datum frame

Genesis has specced the Datum with all the latest tech, such as the direct mount brakes (so modern, in fact, the TRP brakes needed an adaptor – Shimano disc brakes don’t) and a bolt-thru axle on the fork to stiffen up the steering and also keep the disc brake rotor perfectly aligned in the calliper.

We’ve been excited to get our hands on the new 10-speed Shimano Tiagra groupset since its launch earlier this spring. We’re huge fans of 105 – the shape of the brake hoods and the crispness of the gear shift are excellent – and this cheaper Tiagra groupset promises similar performance at a lower cost. First impressions are positive: it feels almost identical to 105, only with one less sprocket on the rear cassette. We expect to see this groupset featured a lot across these pages in the coming year.

Genesis Datum disc brakes

Our test bike came equipped with an 11-32 cassette and a 50/34 chainset, which is enough of a spread to get you up even the steepest of climbs. Our only issue is that the spread of gears at the rear is a little on the large side – we’d probably swap to a 12-28 or similar when the time came to replace a worn chain and cassette.

As we’ve come to expect from Genesis, all the finishing kit is in-house gear and, though not especially exciting, it’s well proportioned. The bars are a good shape for riding in all three positions – tops, hoods or drops – the stem is a sensible length, the saddle is inoffensive and the seatpost does its job of damping vibration acceptably well.

Genesis Datum stays

The last word to say on the Datum regards its paintjob. The deep red paint is stunning and turned a few heads in the office when the bike was first removed from its box.

The new Genesis Datum is a bike for all occasions. It’s versatile and fun, with an obvious thirst for adventure. If that sounds like you, then you’re looking in the right place.


Genesis Datum 10
Frame Datum Carbon, BB86
Groupset Tiagra 4700 10-speed
Brakes TRp Hy/Rd-C
Wheels Fulcrum Racing Sport DB
Tyres Challenge Strada Bianca 33mm 60TPI

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