Specialized has unveiled what it bills as "the world's lightest gravel bike."

Specifically, the new Crux (formerly a pure cyclocross bike) is presented as a dual-purpose machine that blurs the line between "cross" and "gravel"; the top-of-the-line S-Works model is said to weigh just 7.25 kg.

But rather than simply lightening the weight and reclassifying an already gravel-ready cyclocross bike, the brand completely rebuilt the frame, adjusted the geometry, added tire clearance for 47mm rubber, and added a few more gravel-friendly features to open the Crux was opened up to new users.

To learn more, read our review of the Specialized S-Works Crux 2022.

According to Specialized, the new Crux applies technology developed in the development of the Aethos, which rethought the tube proportions and shape to reduce the amount of carbon fiber needed, to the Crux, and Specialized's Road and Gravel Product Manager Stewart Thompson claims it will "change gravel riding forever.

The technology in question was pioneered by Denk Engineering, a team of carbon bike designers led by Peter Denk, who has designed bikes for Cannondale and Scott, but has been exclusive with Specialized since 2014. [How you taper the top tube, how you taper the down tube, how you curve the head tube and bottom bracket is very important," Denk explains. If you follow these geometries, you can get rid of all the stiffening layers. Just by following these geometries, we can reduce the composite weight by 150 grams.

The result is a 56 cm S-Works frame (Fact 12R) weighing only 725 grams and a standard frame (Fact 10R) weighing 825 grams. Both are lighter than the 950g Crux.

Specialized has changed bikes from its previous "pure cyclocross" model, which ranked in the list of best cyclocross bikes, to accommodate the growing interest in gravel riding.

To this end, Specialized lengthened the bike's wheelbase and increased its reach. It also increased the bottom bracket drop (thus lowering the bottom bracket and lowering the center of gravity) and slightly lowered the stack in all but the largest sizes. The Crux's tire clearance was also widened to 700c x 47mm (650b x 2.1in) to match the brand's existing Diverge.

This move clearly opens up the bike to a wider audience and, along with the Diverge, officially grows Specialized's gravel series to two models.

In addition, there are a number of value-added features for gravel riders. Most notable is a third bottle cage mount on the underside of the downtube, and a more subtle addition is the availability of an internally routed dropper post.

Crux is available in four builds: S-Works, Expert, Pro, Comp, and a standalone S-Works (Fact 12R) frameset and Fact 10R frameset, although the 10R frameset is not available in the UK. [S-Works, Expert, and Pro will feature the eTap AXS XPLR on the Red, Force, and Rival models, respectively; Comp will feature the mechanical 1x11 Rival groupset; and the Fact 10R frameset will be available in the UK.