Sometimes you can tell you’re going to like a bike within the first few miles of riding it. The Genesis Datum is one of those bikes.
The Datum is Genesis Bikes second carbon frame after the Zero race bike released a year ago. However it takes more of its inspiration from the classic Equilibrium than it’s carbon sibling as the geometry is very close to that of the newly revised Equilibrium. So the Datum isn’t designed as a gravel bike then, well not from the geometry at least, unless you consider a Genesis Equlibrium a gravel bike that is.
Ok, I’m being a little flippant but when I spoke to Albert Steward, Genesis’s designer about this bike he specifically told me it’s not designed to be a gravel bike – it’s designed to be a tough road bike with big clearances. It’s designed to be fun, comfortable, versatile and great for all kinds of riding, yes including a bit of gravel/bridleway if you want to, but that’s not it’s raison d’être.
There has been a lot of focus on gravel bikes in the last year and it’s such a nebullous category that lots of bikes may touch on it at some level or another, perhaps including the Datum. As a roadie riding on the UK’s potholed and crumbling road surfaces, I want a bike that can excel in these riding conditions – wide tyres and good frame design absolutely make a difference.
Because I’m a roadie and haven’t really done much “dirt” riding, I’ve just been out road riding on it a couple of times so far with friends riding their best summer road bikes and I’ve not felt disadvantaged or like I’ve picked the wrong bike to ride.
One of the reasons that Genesis chose carbon for this new frameset is that it meant they could do more with the shaping to achieve the design goals they had in mind. Looking at the bike, the most obviously place you see this is in the shaped seattube. It features a cut-out like you see on some aero bikes but that’s not the job it’s there for. But putting the cutout in, Genesis could maintain big tyre clearances (you can run 33mm tyres with 45mm mudguards) without having to lengthen the chainstays. This is good because keeping the chainstays shorter sharpens up the handling.
Carbon also made it a little simpler to design the top half and bottom half of the frame with different objectives. The chainstays, downtube, headtube and the lower half of the seattube are all designed with stiffness and performance in mind, whereas the seatstays, top of the seattube and the top tube are designed for compliance. Also for compliance is the 27.2mm seatpost and the 30mm tyres obviously! (They’ll be 33mm tyres on the final production bikes).
In looking at the geometry, I’m not convinced that it’s even that much of an “endurance fit” in the sense of the typical shorter top tube and longer headtube – but it is comfortable and it works (for me certainly). I’ve put my NeilPryde aero bike on the geometry table below – a classic 56cm frameset – 560mm top tube, 160mm headtube and parallel 73 degrees head and seat angle. It comes out with a stack and reach of 575 and 385mm respectively. The size medium Datum has exactly the same reach at 385mm and only an 11mm higher stack. The fact that it’s got a slightly slacker (by 1 degree) head angle works particularly well for my own bike fit. It’s interesting to me as well that the headtube length on the Datum is actually lower than my aero bike (in fairness that’s offset by a number of the other frame design variables) but overall it isn’t radically different. I’ve put the GT Grade on the geometry talbe as a point of comparison and used the large size as it’s the closest to matching the reach of my NeilPryde.
So anyway to keep up with the design features, the Datum design includes the following:
- Geometry closely based around the well proven Equlibrium
- Carbon frame (24/30 ton) with Internal & Di2 compatible routing and standard quick release wheel fitting
- Full carbon fork with a tapered steerer, 15mm through axle, mudguard mounts and massive tyre clearances
- 27.2 mm seatpost for added compliance
- Flat mount disc brakes
The Datum will be sold in three different builds with this being the top of the range 30 with Ultegra Di2 for £3099.99, there’s a £2099.99 Datum in matt black with Shimano 105 mechanical and Shimano flat mount hydraulic disc brakes, there’s a new Tiagra 10 speed version with TRP brakes in a stunning ruby red colour or you can buy a frameset and build your own for £999.99.
On paper, to me, it doesn’t quite fit neatly into any particular box. Do I think that’s a bad thing? Well really that depends on how it rides.
Even though this is only a first look blog post, I’ve managed two 60km roads to date and I have to say I really liked the Datum almost immediately and I can already see why in Road.cc’s review of exactly the same bike they’re saying it’s a contender for bike of the year. Out on the road, my early impression is that the geometry performs very well indeed as does the whole bike. It feels like a road bike, it’s fun to ride, it’s lively, it handles well and descends very well. It’s comfortable thanks to the frame design and the fat tyres (that I’m running at 80psi and could go less).
In this Di2 hydraulic spec it’s a fantastic all-rounder – the groupset and brakes are fantastic and the flat mount brake calipers look a lot more well packaged and discreet than post mount ones. The Datum looks great in the flesh too, the cable routing (including internal fork routing) is very clean, the frame looks modern and well designed – it’s got a lovely paint job too, although I don’t think a white bike is ever particularly easy to keep looking fresh over the long term.
I’m also really enjoying the wide 30mm Challenge tyres. I’ve long since moved on from 23mm unless I simply don’t have room for bigger. I’ve spent the last few years riding 25mm and have just recently been won over to 28mm. The Challenges are perhaps a touch sluggish to initially accelerate but after that they ride really well. Good grip, good comfort, decent road feel – well as much as you can tell in 120km so far.
The finishing kit is also solid stuff too. When I test rode the Genesis Equilibrium a couple of years back, it had the best own brand bars and stem I’d ever used. The production Datum will feature a new “RandoX Flared” flared bars with the same short 70mm reach and a 125mm drop dimensions as the Equilibrium but with an additional flare at the sides and a flatter section for riding on the tops. The review bike has the Equilibrium bars and stem, so the same short reach and drop dimensions and I’ve found them perfect for me.
The only “negative” is that the Datum isn’t a super light bike, weighing in at about 8.8kgs out of the box for the size medium but it doesn’t ride like a heavy bike. It’s also not a bike designed to hit a weight target – it’s about the ride and because it does ride so well, I’m not bothered about the weight. I’ve had a busy summer work and family wise this year so I’m not at all fit but I’ve already managed to get some PRs on Strava on this bike – so like I said earlier, I’ve not found it wanting for speed.
The stock Fulcrum Racing Sport DB wheels (centrelock rotor fit) are not light at just under 1900 gms a pair but they roll wheel and feel tough enough to handle the tough road riding this bike is designed for. I’m probably going to swap in some lighter wheels to see how they change the ride and will report back in due course.
As I’ve already mentioned, I can tell from a couple of early rides this is a bike that I’m not going to want to give back. Early impressions are that it’s a perfect compliment to my aero bike with aero wheels – in that it’s a bike that so far I think I could use for all of my other riding. The fact that it takes proper full mudguards too makes it a compelling winter bike too (if an expensive one in this spec) but you’d happily ride it all year round.
So far, as you’ll have gathered, I’m loving the Genesis Datum and I’ll keep riding to see how and if that changes.
If you’d like to read a little more about it, I recommend this very useful in-depth blog post on the Datum on the Genesis Bikes site that is well worth a read.
Any questions, please let me know in the comments.
Thanks for reading
Update: I’ve now finished my full review on the Datum, which you can read here: https://girodilento.com/genesis-datum-30-review/