Specialized S-works Crux
A helping of gravel, a hint of road, a dollop of cyclocross
It took a Flower of Kent apple falling from a tree and hitting him on the head for Sir Isaac Newton to have his ‘eureka moment’ in developing the laws of motion and universal gravitation. For Specialized engineer Peter Denk, all it took was finite element analysis (FEA), a giant supercomputer and 1,000 simulations to have his own ‘eureka moment’ of reimagined tube proportions and efficient positioning of carbon fibres. The result was the 585g frame at the heart of the Aethos, the world’s lightest production disc brake road bike (see issue 109).
A year later, Denk’s epiphany has been applied to Specialized’s cyclocross model, the Crux, to arrive at the all-new Specialized S-works Crux, which at 725g (56cm) is now the lightest cyclocross/gravel frame on the market.
Shedding the pounds
The Crux has been on a serious diet. When you look back at the last iteration, released in 2018, a 56cm frame weighed 950g. Thanks to the lessons learned from the Aethos, the Crux has trimmed 225g to arrive at that 725g claimed weight, which means this top-end S-works build is just 7.25kg all-in, a full 500g lighter than its predecessor.
You may point out that 500g is only the equivalent of a loaf of sliced bread, but in the world of performance cycling, where every gram counts, a saving of half a kilo is impressive.
What’s more impressive is that this weight saving has not been achieved by speccing exotic components or making the tubes so skinny you live in fear of snapping the frame in two. Specialized has reduced weight by rearranging where the carbon fibre layers are best used in the frame. No trickery – just smart thinking.
Of course, weight isn’t everything. For an off-road bike there are other key performance areas that might normally take priority, such as comfort or handling, but it certainly helps that the Crux goes uphill with such sublime ease. Back in issue 109, deputy editor James Spender wrote that the Specialized Aethos climbed like ‘an invisible force is pulling it’ to the summit. Riding the Crux, which is arguably an Aethos with chunky tyres, I got the same feeling. It’s responsive, it’s stiff, and it does that special thing of making climbing easier.
While the Crux is traditionally the brand’s cyclocross bike, Specialized is promoting this latest version as a gravel bike first, cross bike second. The reason is almost certainly to
It’s reactive and requires more focus to negotiate a route around rocks and roots, rather than just blundering over the top
broaden its appeal, however there will be those who point out that Specialized already has gravel covered with its Diverge, so why push the Crux into the same segment? The answer is that the two bikes serve completely different purposes.
The Diverge has a longer wheelbase for stability; it has the squidgy Futureshock stem suspension and more storage solutions and mount options than a piece of Ikea furniture. The Crux has tighter geometry closer to that of Specialized’s Tarmac road bike – only a few millimetres different, in fact. There is no use of Futureshock, no mounting points, and ultimately a very different feel to the armchair ride of the Diverge.
Rather than just rumbling over rough terrain, the Crux skims over it like a flat stone skipping across the ocean, putting the emphasis back on bike-handling ability but doing so while going undoubtedly faster than the Diverge possibly could.
For me, some gravel bikes have been overengineered to a point where the majority of gravel riding that I am exposed to – muddy singletrack and byways – is now too easy, and to rediscover the fun and challenge usually associated with riding off-road I’m forced into riding more technical trails, a move that would suggest I should probably just buy myself a hardtail mountain bike. This isn’t the case with the Crux. It put an excited smile back on my face.
Taking the scenic route
This is not to say the Crux is hard to handle, it’s just more reactive and requires more focus to negotiate a route around rocks and roots, rather than just blundering over the top of them. And, equally, this is not to say the Crux isn’t capable off-road. Tyre clearance is up from 33mm to 47mm for 700c wheels, or 2.1in with 650b, a width that could get you across quicksand if need be. On this particular spec I had a set of 38mm Specialized Pathfinders, which dispatched whatever I threw at them with ease.
So maybe this isn’t the bike you want for touring around the world, but it’s certainly fast and fun for short outings, whether that’s a cross race or just a blast around your local woods.
I do have one complaint, though: £10,750 is fully £2,500 more than the 2020 Crux and far more than the vast majority of gravel or cross bikes. Lightest gravel bike in the world or not, for that price I’d want the thing to ride itself.