The rims on the WH-RS81-C24-CL wheels feature a proprietary, in-house construction where carbon is lamented to a thin aluminum rim. You then get the best of both worlds. The carbon portion is light and stiff does an excellent job of dampening the ride while enhancing the strength of rim at the same time. The alloy braking surface is far superior to carbon and is incredibly durable.
The WH-RS81-C24-CL is 11-speed compatible and comes with a 1.85mm spacer so it will work with 10, 9, 8-speed and SRAM too. The hubs are based on Dura-Ace design featuring angular contact bearing and labyrinth seals. The flanges are super wide increasing the distance of the spokes between the flange creating a wider footprint for a far stronger and more stable wheel. The front wheel is 16 hole with a radial lace, while the rear is 20 hole with a 2x lacing pattern.
In terms of how the wheels ride, we would have to say 2 words that comes to mind are fast and comfortable. Many factory wheels have a stiff ride quality because they use fewer spokes at a higher tension. Shimano builds the WH-RS81-C24-CL to ride like a well-conceived hand-built wheel that soothes rough roads white having plenty of rigidity when needed for hill sprints and criteriums. You also get a particular amount of built in durability and longevity with the hubs, because of the design - they will last many seasons with no required maintenance. Over the past few years this carbon-hybrid rim design has proven to be as durable as anything else currently on the market. Includes skewers, rim tape, and spoke wrenches.
I've had them for over a year now, put many thousands of miles on them, and they are still as perfect as the day I bought them. Honestly, I think they roll smoother now! They are probably the most well built wheelset I own (out of about 10 sets), laterally stiff enough for sharp climbs and sprints, yet compliant enough for all day riding. As for maintenance, I've adjusted the bearing once (they come tight from shimano). Additionally, it just so happens that shimano sponsored protour teams (HTC, sky etc) have traded down from dura ace to these wheels for training. A great set to have for any type of rider.
I'm running these wheels with Hutchinson Fusion 3 tubeless tires on my Cervelo R3. The best ride I've ever had. Let a few pounds out and they're also very good on dirt roads. Almost 1000 miles and still as true as the day I mounted them.
Pros: Pretty light, priced right, stiff but comfortable
Cons: They don't have the bling of $3,000 Zips
This is an update to my original review. After a longer ride of 30 miles in some hilly country I can confidently say that this is the best wheel set you can buy at this price point. These wheels tranfer power to the road better than any other wheels Ive used. I was able to reach the top of the steeper climbs much faster than with any of the Mavic wheels I had used and even while being stiff, these wheels ride incredibly smooth. In corners, I find myself braking much less. I almost seems as if these wheels could cut a groove in the road. Keep in mind that this is the same rim as the Dura-Ace but with Ultegra hubs. I dont think you can go wrong with this wheel set. Excel shows this wheel set to weigh in at 1560 grams but they actually weigh 1516 grams. Less than the Kysrium Elite and performs better.
Bike: Felt F4
Components: Ultegra SL
Tires: Vitorria Rubino Pro
I just bought this wheel set from Excel at an amazing price. Without a great deal of time for a test I must say these are the stiffest wheels Iv ever ridden on. In a short 10 mile ride at a high pace, I found these wheels to be very reliable in corners and accelerated very well out of corners. I was able to reach the top of a short 6 percent climb at a higher speed than ever for that climb. That said, Im assuming the steeper climbs will be much easier. The carbon overlay damps road buzz extremely well. Ive always been a fan of Mavic wheels and had always been pleased with Ksyrium Equipe and Kysryium Elite but the RS80 out performed both of those with ease.
Bike: Felt F4 Carbon
Components: Shimano Ultegra SL 10 speed
Tires: Vittoria Rubino Pro
I would highly recommend this wheel set.