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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.
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.
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.
Stiff, fast-reacting wheels built to a very high standard and with the reliability of an aluminium brake track
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road.cc test report
Make and model: Shimano Dura-Ace C24 Carbon Clincher wheelset
Size tested: 700C
Tell us what the wheel is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Shimano says: "WH-R9100 CL carbon clincher wheel, designed to meet pro road race criteria"
Tell us some more about the technical aspects of the wheel?
Full carbon / alloy 21 mm deep 20.8 mm wide rim
Low rim weight is achieved by reducing the alloy wall thickness from 1.3 mm down to 0.7 mm, then a patented phosphoric acid anodizing process is used to bond the carbon fibre to the alloy giving an excellent combination of low weight, strength and rigidity
Carbon reinforced spoke eyelets increase durability
Alloy clincher rim maintains high braking performance with standard brake pads in all conditions
Front: 16 stainless steel butted (2.0-1.5-2.0) and bladed straight pull spokes
Rear: 20 stainless steel butted (2.0-1.8-2.0) and bladed straight pull spokes
Elbow-less spokes make for a strong yet compliant wheel
High lateral rigidity is produced with a wide flange spacing
Labyrinth double-contact sealing effectively shuts out water and dirt
Alloy cone with integrated steel Borozon treated bearing races - super mirror finish reduces friction
Quick and easy to maintain digital click bearing adjustment
Cold forged, machined aluminium hub shell and oversized 7075 alloy axle keep the wheel weight to a minimum
700C clincher compatible
Supplied with Q/R skewer
Average weight front: 585g
Average weight rear: 804g
The price has gone up considerably over the Dura-Ace 9000 version of this wheel, but the distributor tells us that's because of currency changes as a result of Brexit.
Did the wheels stay true? Any issues with spoke tension?
They've stayed absolutely true with no need for fettling.
How easy did you find it to fit tyres?
How did the wheel extras (eg skewers and rim tape) perform?
Great. The large lever at the end of the quick release is easy to use.
Tell us how the wheel performed overall when used for its designed purpose
It's light, stiff and responsive.
Tell us what you particularly liked about the wheel
The fact that it reacts fast and efficiently.
Tell us what you particularly disliked about the wheel
The price rise is a shame, but that's not unique to Shimano.
Did you enjoy using the wheel? Yes
Would you consider buying the wheel? Yes
Would you recommend the wheel to a friend? Yes
Use this box to explain your score
These put in a strong performance across the board. Yes, the price has gone up considerably in the UK (from £849 to £999), apparently as a result of currency changes, but these are exceptionally good wheels.
About the tester
I usually ride: My best bike is:
I've been riding for: Over 20 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding
Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.