Replacing the highly regarded RS80 wheels, the Shimano RS81s have been released to coincide with Shimano's foray into 11-speed transmissions; they still work with all existing 10-, 9- and 8-speed gearing as well.
The rims are alloy with a carbon fibre laminate overlaid to increase stiffness without adding much in the way of weight, and bring the depth up to the 35mm implied by the name. It also makes them look rather dashing.
While we are on the subject of weight the C35s measure 1700g on the road.cc scales, including rim tapes but not skewers. Not exactly lightweight but the RS range of wheels are built more for durability and day to day riding/racing rather than all out lightness. That weight though stacks up pretty well against the 1665g Zipp 30s tested recently for a similar depth rim and price bracket.
Like the Zipps the rims on the RS81s are pretty wide at 20.8mm. We've seen a lot wider rims recently for a couple of reasons, It improves the aerodynamics of the tyre and rim combination because it makes for a smoother transition between the two, and it also makes the rim laterally stiffer, and the wheel stronger.
Spoke numbers are minimal with just 16 up front and a slightly rare count of 21 at the rear laid out as 14 drive side and 7 on the non-drive. The spokes themselves are butted stainless steel straight pulls with a bladed mid-section so should be plenty strong enough for all kinds of riding over different terrain.
The hubs are cold forged with alloy axles for a bit of weight saving and the bearings are sealed and adjustable, always a pleasure to hear if you're going to be using them all year round in our rather temperate climate.
Out on the road they certainly feel solid with an underlying feeling of stiffness yet they aren't harsh, thanks to that small amount of carbon just taking the buzz out of the alloy. The machined surface gives consistent braking and there is no sign of any judder from where the rim has been welded.
The numbers on the scales don't reflect the feedback from the C35s as acceleration is brisk and once up to speed it is very easy to maintain no doubt thanks to the slight aero advantage of that 35mm rim.
Sprinting and climbing both require plenty of stiffness at the rim especially for the heavier rider and the RS81s don't disappoint here either. Really cranking the bike from side to side for that all important village sign sprint saw absolutely no brake block rub from rim flex and I tend to run my brakes close, a millimetre or so away from the rim.
The hills provide very little issues and while they don't climb like some of the superlight hoops weighing less than say 1500g they don't feel like you're dragging them up either. Coming down, the weight adds to their advantage as they roll through the rough surfaces rather than bounce over them giving a good sense of control.
Performance is impressive but that rrp of £599.99 is right on the limit. My initial thoughts over the first few test rides were how similar the RS81s are to Mavic's Ksyrium Elites with that solid secure feeling, a bit of extra weight and overbuilding for long term reliability. But the Ksyrium Elite S wheels are a 100g lighter on claimed weights and a hundred quid cheaper. Competition like that puts the RS81s on the back foot a little.
As we've gone from summer into autumn the RS81s have seen a lot of rain and grit and there has been no grumbling from the bearings at all; they still feel as smooth as day one. Braking seems to be pretty consistent in the wet too.
On the whole though I'm impressed with the RS81s. You can crash into a pothole, take them out in the rain and not worry too much about longevity. They also look smart in a non shouty kind of way with the simple graphics and glossy carbon fibre.
I found them for £475 online which moves them into a whole different ball park and at that price I'd happily pay for them.
Solid, good looking wheels from the Japanese giant but not worth the full retail price; shop around for a deal.
road.cc test report
Make and model: Shimano RS81 C35 wheels
Size tested: n/a
Tell us what the product 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?
The RS81s are designed as mid-level race wheels that are capable of being used daily for training as well. Or as Shimano put it: High performance road racing wheel meets the demands of today's professional and amateur riders.
Tell us some more about the technical aspects of the product?
-Carbon and alloy clincher rim is both light weight and rigid whilst maintaining high braking performance with standard brake pads
-20.8 mm wide carbon rim with alloy braking surface for improved aerodynamics and increased rigidity for sprinters and TT specialists
-21 rear and 16 front stainless steel butted and bladed straight pull spokes for optimal balance and rigidity (OPTBAL)
-High lateral rigidity is improved with a wide flange spacing
-Labyrinth double contact sealing - low-friction seals effectively shut out water, mud and dirt without affecting rotational smoothness
-Quick and easy to maintain digital click bearing adjustment
-Polished bearing races reduce friction and provide for smooth rotation
-Cold forged and machined aluminium hub shell and oversized 7075 alloy axle keep the wheel weight to a minimum
-8, 9, 10 and 11-speed compatible
-700C clincher compatible
-Supplied with Q/R skewer
Very well built indeed.
Good, solid all-rounders.
That durability comes at a cost.
Stiff yet comfortable.
At the top limit of what I'd consider paying but as with everything there are plenty of deals around.
Tell us how the product performed overall when used for its designed purpose
As a day to day wheel they perform very well shrugging off knocks and bad weather yet still look like a top end wheel.
Tell us what you particularly liked about the product
the looks and the ride characteristics.
Tell us what you particularly disliked about the product
The price is a touch high.
Did you enjoy using the product? Yes.
Would you consider buying the product? Possibly.
Would you recommend the product to a friend? Yes.
About the tester
Age: 35 Height: 180cm Weight: 76kg
I usually ride: Ribble Winter Trainer for commuting, Genesis Flyer My best bike is: Sarto Rovigo
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, club rides, sportives, fixed/singlespeed,
With a background in engineering dabbling as a CNC programmer/machinist, draughtsman and product development engineer how a bike is made is just as important to Stu as how it rides.
He knocked out his first road.cc review back in 2009 and has been chucking bikes around the west country ever since and the only reason he climbs is so that he can descend like a nutter down the other side. After years as a competitive time triallist Stu is on the lookout for a new form of competition after realising that the choice of a few glasses of wine in the evening versus riding up and down dual carriageways at 5am was becoming very one sided.