Shimano Dura-Ace C24 Carbon Clincher wheelset

Shimano's Dura-Ace C24 carbon laminated wheels are light, stiff and responsive, putting in an excellent all-round performance.

I've been running the C24s with 25mm Continental Grand Prix 4000 tyres (Shimano advises that you use tyres ranging from 23mm to 28mm with these wheels) and they've been very quick, accelerating fast, and the ride quality is hard to fault.

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The C24s, which have just been given a graphics/aesthetics update to match Shimano's new R9100 components, have the shallowest rim heights of any wheels in the Dura-Ace range: the front is 21mm and the rear is 24mm. They're not particularly wide either: 15mm internal, 20.8mm external, whereas the new C40 and C60 clinchers are both 17mm internal and 24mm external, following the trend towards more width.

The rims are aluminium alloy with a CFRP (carbon fibre reinforced polymer) laminate on the hub-facing surfaces. The aluminium wall thickness is just 0.7mm and Shimano uses 'a patented phosphoric acid anodising process to bond the carbon fibre rim to the alloy [to ensure] an excellent combination of strength, rigidity and a low weight'.

Our review wheels came in at 601g (front) and 820g (rear), a total of 1,421g (without rim tape or skewers). That's a little higher than Shimano's claimed 1,389g but it's still impressively light, particularly as Shimano hasn't compromised quality or durability here.

The hub shells are aluminium too, with a titanium freehub body at the rear. The wheels spin on cup and cone bearings, as is the Shimano way. The sealed cartridge bearings that most other brands use these days might be fit and forget but Shimano's design allows you to adjust the preload or give the bearings a complete service to ensure optimum performance and maximum longevity... as long as you know what you're doing (if not, you can take them to your local bike shop, of course). The labyrinth double-contact seals have managed to keep the stainless ball bearings running free of water and gunk during a particularly wet and mucky review period.

You get 16 straight-pull butted and bladed spokes in the front wheel and 20, laced two-cross, at the rear. Attached to very widely spaced hub flanges, they provide excellent levels of stiffness that you notice particularly while cornering hard or riding out of the saddle. I only managed to get brake rub when I set the pads stupidly close to the rims and rode uphill in a ridiculously hard gear; in all realistic circumstances there was none at all. The wheels feel taut and efficient.

Braking is up to the standards you'd expect on an aluminium brake track – which means it's better than you get with any carbon fibre rims out there. A few brands, notably Mavic, have improved the quality of carbon fibre braking lately, but none has the bite or consistency that you get with something like the C24 wheelset.

Shimano doesn't make any aerodynamic claims for the C24s. If you're looking to reduce drag you need to step up to the C40s or the C60s. What you do get here is that lightness and responsiveness that I've mentioned and, as you'd expect, a shedload of stability no matter what the wind is doing.

The other point that's worth mentioning here is the ride quality. I'm not a big one for talking about smoothness when it comes to wheels but these do take an appreciable amount of road buzz out of your ride, and that makes a big difference to the way you feel.

> Buyer's Guide: Road bike wheels

These wheels have required no truing during the two-month test period and the titanium freehub is virtually unmarked so it looks like it'll go the distance.

All in all, these are very impressive wheels. They don't have the width of many modern designs, nor the aerodynamics, but they are light and fast reacting, and the alloy brake track adds to their all-weather versatility.

Verdict

Stiff, fast-reacting wheels built to a very high standard and with the reliability of an aluminium brake track