Alloy-carbon hybrid construction

These C24s have always been a bit different in their construction and it’s difficult to pigeon-hole them as either carbon or alloy clinchers, as is the case with most wheels. You see, while the outer surface of the rim U-section is visibly a carbon laminate, the brake track is very clearly aluminium.

• Specification

• Price: £999.99
• Weight: 1,389g (claimed)
• Rim depth: 21mm front, 24mm rear
• Rim width: 20.6mm external; 15mm internal
• Website: Shimano
• UK distributor: Madison

The idea behind this is to ensure the predictable rim braking performance you get from an aluminium track (in the wet and dry), while the carbon laminate is intended to reduce weight compared to a standard alloy construction.

Underneath the skin, you’ll find a 0.7mm alloy wall on the inside of the carbon laminate, there for added strength and rigidity, according to Shimano. Combined with the carbon laminate it results in a rim wall that’s around as thick as any chosen alloy clincher.

This construction has been shaped into rim depths that measure 21mm at the front and 24mm at the rear, along with a rim bed that measures 15mm internally and 20.8mm externally – markedly narrower than is commonly seen these days. Mavic’s latest Ksyrium Pro UST wheels have an internal width of 17mm, for example, while Hunt’s Race Aero Wide wheelset ups this once again to 19mm.

Light and responsive… but a little dated

First and foremost, the low weight of the wheelset means that the C24s are definitely no slouches going uphill. They particularly excel on steeper climbs, where the combination of a lightweight rim and the high levels of stiffness afforded by the wide-angled flange design means you can really put all your effort into the pedals and get an excellent feedback from the wheels.

There is a caveat to that, however. Thanks to the Dura-Ace moniker, these wheels come with an element of expectation but when measured against really high-spec shallow carbon or alloy clinchers (let’s say, Mavic’s Ksyrium Carbon SL C hoops, or the French brand’s top-end alloy R-Sys wheels we saw on a Rose X-Lite test bike recently), you do miss an element of ride excitement – that feeling the wheels are adding something really special to your outings.

“The C24s are definitely no slouches going uphill and particularly excel on steeper climbs”

Both of those Mavic wheelsets cost upwards of £500 more than the C24s, so it’s not an entirely fair comparison, but the point is while Shimano’s C24 wheels bear the Dura-Ace name, these particular hoops still sit a rung below the very best lightweight clinchers.

Fair enough, given the C24s are pitched as a high-spec wheelset that can be used in as diverse circumstances as a mountainous race (we’re told that if you look hard enough you’ll spot them under pros during high mountain stages at Grand Tours) or as a deluxe training wheel.

Finally, thanks to the brake track being a standard alloy affair, there’s excellent performance across the board, with reliable power and modulation between my Dura-Ace R9100 calipers. One of the chief benefits of an alloy brake track is an assured level of performance in all conditions and the C24s are as close to a safe-as-houses option as it’s possible to get.

Conclusion

The reality is, if you’re after a set of alloy, sub-£1,000, high-performance wheels, Shimano’s Dura-Ace C24 hoops remain one of the most dependable options out there. You’ll likely find the C24s at a hefty discount, too, which also makes them competitive on price.

Quality, fully-serviceable hubs, lightweight rims and an alloy brake track are all points in their favour, along with the prestigious Dura-Ace name, but the narrow rim is a compromise which is starting to look a little out of date. The C24s are due an update.

However, while the C24s may not be the most advanced or outright exciting wheels in Shimano’s flagship Dura-Ace range, these are hoops which offer stiff, responsive and reliable performance, whether you want a luxury wheel for year-round riding or are on the lookout for an upgrade to breathe new life into your machine.

Pros

• Lightweight
• Responsive
• Serviceable bearings
• Reliable alloy rim braking

Cons

• Narrow rim by modern standards
• Can’t match the very best alloy wheels