The new Specialized Crux is “the world’s lightest gravel bike” | 725g for a 56cm S-Works frame

The new Specialized Crux is claimed to be the world’s lightest gravel bike, boasting a claimed weight of 725g for a 56cm frame, with top-end complete builds starting at 7.25kg.

The new bike steps away from its cyclocross roots and is now billed as an uncompromising ultra-light gravel bike that borrows much of its design and tech from the similarly feathery Specialized Aethos road bike.

Despite its light weight, the new Crux retains genuine real-world practicality, with clearance for tyres up to 2.1in wide on 650b wheels, or 47mm wide on 700c wheels. It also sticks with a threaded bottom bracket shell, and can even accommodate an internally routed dropper seatpost.

With clean lines, a simple frame and no mudguard or rack mounts, the bike stands apart from the Specialized Diverge and is – to quote Specialized – aimed at riders looking for “gravel enlightenment”.

It probably won’t surprise you to hear that all of this comes at a, to put it mildly, very high premium, with the top-end S-Works model we've been testing coming in at $12,000 / £10,750 / €12,200 / AU$18,000. For that, you get Specialized’s top-end S-Works 12r carbon frameset, a full SRAM Red eTap AXS XPLR groupset and Roval Terra CLX wheels.

For those without bottomless pockets, the Pro, Expert and Comp bikes use the slightly heavier 10r layup, which adds a claimed 100g to the frame weight, but will save you a fair chunk of cash, with the cheapest build coming in at £4,000 / $4,200 / €4,000 / AU$6,300.

Laying down the facts on the layup

Compared to a modern carbon road bike, the Crux is quite organic in form, with the tubes flowing into each other smoothly. This contrasts with the more angular frame shapes seen on most road bikes, which usually appear in the name of aero gains.

According to Specialized, on a typical frame, these angular areas require reinforcing layers of carbon. This is because carbon isn’t as strong when laid up over sharp angles.

In comparison, Specialized claims the smoother overall design of the Crux allows it to use “longer, unbroken plies” that are laid up around and over the tube junctions in the frame.

This means the frame requires fewer stiffening layers to maintain strength, reducing weight by a claimed 150g in the case of the Crux, compared to a conventionally designed frameset.

All of this adds up to a claimed 725g frame weight for a size 56cm S-Works frame in the lightest paint job without hardware.

To put that into context, it’s only 165g heavier than an equivalent Aethos frame, which is pretty remarkable when you consider the Crux is rated for off-road riding.

It also has a fairly reasonable 125kg rider weight limit (although it’s important to note that the weight limit for some of the components specced on the complete bikes is 109kg).

The cheaper 10r frame, which is used on the Pro, Expert and Comp level bikes, is claimed to weigh 825g in the same spec.

The same 12r fork is shared across all bikes, and is claimed to weigh around 400g with a steerer cut for a 56cm frame.

Elsewhere, the frame has been slimmed down as much as possible, using the same lightweight thru axles and seat clamp as the Aethos.

Cleared to send

Tyre clearance on the new Specialized Crux stands at 2.1in for 650b wheels, or 47mm for 700c wheels. This is the same as the Diverge.

A key marketing claim about the new Crux is that, for its (genuinely impressive) light weight, the bike features very large tyre clearances.

Taking both of these factors into consideration, it has produced a graph demonstrating the “clearance to weight ratio” of the Crux compared to similar bikes on the market.

While we admit to doing a fairly intense eye roll when we first saw this, we have to give credit where it’s due – in the press pack for the bike, Specialized acknowledges with a tongue firmly planted in its marketing cheek that “the industry needs another standard” for comparing bikes.

While ‘clearance to weight’ is unlikely to become a key buying decision for most riders, it's still an interesting way to illustrate where the bikes sit in the overall market.

Specialized says no to integration

The new Crux is designed to use a standard two-piece cockpit. The two top-spec bikes get the new-ish Roval Terra carbon handlebars, which boast an impressive 200g claimed weight, with cheaper models given alloy bars.

Opting for a classic cockpit means the new Crux forgoes fully internal cable routing in favour of a lighter (and easier to maintain) semi-integrated solution.

Cable routing on the frame is handled by a port that sits just behind the head tube at the top of the down tube. The bike uses full-length housing, which runs all the way around the bottom of the standard ISO-threaded bottom bracket cup.

Up front, the brake hose enters the left leg of the fork just below the crown.

You can have whatever you want so long as it's 1×

The new Crux is designed primarily to work with 1× drivetrains and all complete builds are specced with 1× SRAM drivetrains.

However, the frame also includes an integrated front derailleur mount that will work with Shimano GRX or eTap front derailleurs. The bike is not compatible with mechanical front derailleurs, nor will it work with Shimano road double cranksets (there's more info on this in the section on using the new Crux as a cyclocross bike).

The top-end S-Works Crux is specced with a Roval Alpinist carbon seatpost, with cheaper models getting the slightly heavier Roval Terra carbon post. The bike also moves away from the integrated seatbinder seen on the old bike in favour of a good ol’ fashioned external seat clamp.

For the shredders among you, the bike is also designed to work with any internally-routed 27.2mm dropper posts – though the likes of the wireless RockShox Reverb AXS will, of course, offer the easiest plug-and-play dropper solution.

The bike has three bottle cage mounts, with the third sitting on the underside of the down tube towards the bottom bracket shell. As mentioned, there are no mudguard or rack mounts on the frame, nor does it have a top tube mount seen on many new gravel bikes.

New Specialized Crux geometry

The geometry of the new Crux is broadly similar to the outgoing bike – which was notably low and slack for a cyclocross bike anyway – but Specialized has made a few small tweaks on the new bike.

To start, and in line with broader industry trends, reach has grown by roughly 10mm across the board (388mm vs 397mm for a 56cm bike compared to the old model).

Increasing reach allows riders to reduce their stem length, keeping weight distribution more biased towards the rear of the bike, which can improve handling in steep terrain.

Trail has also been increased by a small amount, presumably to calm down steering at higher speeds.

Finally, the bottom bracket drop has also been increased, though, thanks to the fatter tyres specced on the new Crux, the published effective bottom bracket height is essentially the same (the old bike was optimised to work best with 33mm tyres, which is the widest permitted by UCI rules for cyclocross racing).

Otherwise, the geometry of the new bike is broadly the same, so those looking to upgrade from an older Crux are unlikely to find their position hugely different on the new bike.

The new bike is available in six sizes compared to the old model’s seven, with shorter riders no longer able to get a size 46cm frame.

With that said, the standover height of the new 49cm frame is actually considerably smaller than the old 46cm frame, coming in at 749mm on the new Crux vs 763mm for the old model.

Is the new Specialized Crux just a cyclocross bike?

The Crux was introduced in 2010 and, though many people turned it to gravel duties, it was designed nominally as a cyclocross bike.

The new Crux makes a clean break with cyclocross specificity and Specialized will not offer the bike in a 'cross-specific build. Despite this, the new bike will be used by the brand’s sponsored athletes, such as Zdeněk Štybar and Kata Blanka Vas, in cyclocross races.

Why abandon 'cross altogether with the new bike?

Put simply, the market for dedicated cyclocross bikes is vanishingly small when compared to gravel, which by some brands’ measure is now their biggest category overall.

Specialized was also keen to point out that serious cyclocross racers will likely have very specific requirements, and any stock build is unlikely to meet their needs.

For sponsored athletes or those who are dead-set on building up a new Crux as a 'cross bike, there's still the option to build up their bike from a frameset (which is UCI-approved).

An interesting note on compatibility for 'cross racers: the new Crux frameset is designed to work primarily with 1× cranksets, but will also work with 2× Shimano GRX and SRAM 2× cranksets. It is, however, not compatible with 2× Shimano road cranksets due to clearance issues at the seatstays.

Given top cyclocross racers sponsored by Shimano often choose to run its 2× road chainsets with close-spaced chainrings (this includes the aforementioned Stybar), this could result in some interesting builds, as GRX is only available with 48/31t chainrings.

Will these riders opt for third-party chainrings for GRX cranks or will they all move to 1×? We look forward to finding out.

Specialized Crux pricing and range overview

The range-topping Specialized S-Works Crux will set you back $12,000 / £10,750 / €12,200.

For that, you get a pretty-much-best-of-everything build that includes a full SRAM Red eTap AXS XPLR groupset, carbon Roval Terra wheels and all manner of other lightweight goodness.

Out of curiosity, we had a look back at the 2018 S-Works Crux, which cost $7,500 for a Dura-Ace 9170 Di2 build – that’s a 60 per cent increase.

The changes aren’t quite so chasmic at the cheaper end of the price spectrum, with the Comp-level bike, which is specced with a SRAM Rival groupset coming in at $4,200. The previous-generation bike was $3,200 for a broadly similar spec.

It’s important to note we're sort of comparing apples to oranges here – the new Crux uses a fairly novel construction method and a higher grade of carbon, whereas the older model used more traditional techniques. Specialized is also hardly alone here, with all brands increasing the price of their bikes across the board (the new Trek Checkpoint also has a top-end $12,000 build option, for example).

2021 Specialized S-Works Crux price and specs

• Frameset: S-Works Crux 12r Carbon, 68mm threaded bottom bracket, 12x142mm thru-axle, flat-mount disc
• Handlebars: Roval Terra, carbon, 103mm drop, 70mm reach, 12-degree flare
• Stem: S-Works SL, 6-degree rise
• Handlebar tape: Supacaz Super Sticky Kush
• Saddle: Specialized S-Works Power
• Seatpost: Roval Alpinist
• Seatpost clamp: Specialized alloy, 30.0mm, titanium bolt
• Shift levers: SRAM Red eTap AXS
• Rear derailleur: SRAM Red XPLR eTap AXS
• Cassette: SRAM XPLR XG-1271, 10-44t
• Crankset: SRAM Red AXS power meter, 40t
• Chain: SRAM RED 12-speed
• Wheelset: Roval Terra CLX
• Tyres: Pathfinder Pro 2Bliss Ready, Transparent Sidewall, 700x38c
• $12,000 / £10,750 / €12,200 / AU$18,000

2021 Specialized Crux Pro price and specs

• Frameset: Crux FACT 10r Carbon, 68mm threaded bottom bracket, 12x142mm thru-axle, flat-mount disc
• Handlebars: Roval Terra, carbon, 103mm drop, 70mm reach, 12-degree flare
• Stem: Specialized Pro SL, 6-degree rise
• Handlebar tape: Supacaz Super Sticky Kush
• Saddle: Specialized Power Pro
• Seatpost: Roval Terra Carbon
• Seatpost clamp: Specialized alloy, 30.0mm
• Shift levers: SRAM Force eTap AXS
• Rear derailleur: SRAM Force XPLR eTap AXS
• Cassette: SRAM XPLR XG-1251, 10-44t
• Crankset: SRAM Force 1×
• Chain: SRAM Force 12-speed
• Wheelset: Roval Terra CL
• Tyres: Pathfinder Pro 2BR Ready, Transparent Sidewall, 700x38c
• $8,000 / £7,000 / €8,000 / AU$12,000

2021 Specialized Crux Expert price and specs

• Frameset: Crux FACT 10r Carbon, 68mm threaded bottom bracket, 12x142mm thru-axle, flat-mount disc
• Handlebars: Specialized Adventure Gear, alloy, 118.9mm drop, 70mm reach, 12-degree flare
• Stem: Specialized Pro SL, 6-degree rise
• Handlebar tape: Supacaz Super Sticky Kush
• Saddle: Specialized Power Expert
• Seatpost: Roval Terra Carbon
• Seatpost clamp: Specialized alloy, 30.0mm
• Shift levers: SRAM Rival eTap AXS
• Rear derailleur: SRAM Rival XPLR eTap AXS
• Cassette: SRAM XPLR XG-1251, 10-44t
• Crankset: SRAM Rival 1×
• Chain: SRAM Rival 12-speed
• Wheelset: Roval Terra C
• Tyres: Pathfinder Pro 2BR Ready, Transparent Sidewall, 700x38c
• $6,000 / £5,500 / €6,000 / AU$9,000

2021 Specialized Crux Comp price and specs

• Frameset: Crux FACT 10r Carbon, 68mm threaded bottom bracket, 12x142mm thru-axle, flat-mount disc
• Handlebars: Specialized Adventure Gear, alloy, 118.9mm drop, 70mm reach, 12-degree flare
• Stem: Specialized 3D forged, 6-degree rise
• Handlebar tape: Supacaz Super Sticky Kush
• Saddle: Specialized Power Sport
• Seatpost: Roval Terra Carbon
• Seatpost clamp: Specialized alloy, 30.0mm
• Shift levers: SRAM Rival 1
• Rear derailleur: SRAM Rival 1
• Cassette: SunRace 11-42t
• Crankset: SRAM Rival 1x
• Chain: KMC X11
• Wheelset: DT Swiss G540 Disc
• Tyres: Pathfinder Pro 2BR Ready, Transparent Sidewall, 700x38c
• $4,200 / £4,000 / €4,000 / AU$6,300

2021 Specialized S-Works frameset

• $5,000 / £4,4000 / €4,500 / AU$7,500

2021 Specialized Crux Pro frameset

• $3,200 / £N/A / €3,000 / AU$4,700