The Giant SLR 0 65mm Carbon wheels are superfast, handle well for their rim depth and are impressively light considering the amount of material in the rims. They're expensive at face value but are priced to undercut similar-spec wheels from the likes of Shimano, Roval and Enve.
With its 65mm rim depth, the SLR 0 65mm 'Wheelsystem' is designed, according to Giant, for when speed is all that matters. That might suggest that handling is not top of the agenda, but stability in crosswinds is good for this type of wheel.
The aero rim is backed up by top-quality Giant-shelled DT Swiss 240 hubs and DT Aerolite bladed spokes, making it a formidable package best suited to time trialling or fast road racing over flat or rolling terrain, although at a very reasonable 1,620g they will go up all but the very steepest hills pretty quickly.
With their mean look, they're also likely to intimidate the opposition wherever they're ridden. The unusual colouring in a couple of our pics is just the way the light catches the fibres, by the way.
This is the third set of Giant carbon wheels I've tested and I've liked all of them a lot. I sometimes wonder if Giant gets left off wishlists for upgrade wheels because it's not a specialist wheel brand. But as the world's largest bicycle company it is able to harness a huge amount of design, tech, manufacturing and purchasing power, and this shows in the performance, the quality and the competitive price of its wheels. The other thing that might deter wheel buyers is the thought that Giant wheels might not match their Specialized or Trek. Well, they're easily destickered, leaving stealth-black unbranded carbon rims.
The all-carbon rim has a 19mm internal width, which marks it out as belonging to the new generation of wider-rimmed aero wheels.
A 25mm tyre sits perfectly on the SLR 0, its sidewalls more or less flush with the 23mm external rim width, and is probably the minimum width you should use with a 19mm rim.
Spoke count benefits from these being rim rather than disc-brake wheels. The front gets just 16 radial spokes (compared to 21 in the disc version) and there are 21 at the back, in Giant's Dynamic Balanced Lacing, a clever system designed to balance spoke tension under pedalling forces for a stiffer, more efficient ride, according to Giant.
The alloy hub shells are Giant branded but contain DT Swiss internals: the Ratchet System freehub of the DT 240 hub picks up crisply and freewheels with a muted purr rather than the swarm-of-angry-bees-wielding-a-buzzsaw noise of some (Hunt, I'm looking at you). A quiet freewheel is much more sociable on a group ride.
The bladed spokes are DT Aerolite, which are lighter than the Sapim CX Sprints that Giant's website lists in the spec (this is due to be corrected).
Giant includes a tubeless valve kit and rim tape in the box, but I ran the SLR 0 65s with clinchers and tubes and they worked perfectly well.
As with the previous two Giant carbon wheels I've ridden, a standard clincher tyre bead doesn't always move up easily into Giant's tubeless rim bead hook profile, meaning you can be left with a low spot that won't right itself even when the tyre is overinflated. Dribbling a little bit of soapy water – as you would use with a tubeless setup to get a very tight tyre over the rim with a tyre lever – sorts it, but in this case dribble it into the rim after you've got the tyre over the rim (so as not to make it too slippery for thumbs) before inflating.
The good news is that getting standard clinchers over Giant's tubeless rim is achievable with thumbs, unlike with some tubeless rims. I fitted Continental Grand Prix 4 Season clinchers as it was winter when I tested them (the show must go on etc) and my palms and thumbs stayed blister-free.
For setting them up tubeless, Giant puts long tubeless valves and tubeless rim tape into the box, or will fit them with its Gavia tubeless tyres for you if you specify this.
Giant also supplies brake pads specifically for use with its carbon wheels and it is essential to use these if you want to stop safely and look after your brake tracks. You also get QRs in the box.
Giant's deepest wheels are undoubtedly fast and have, as its marketing announces, been designed for when speed is all that matters. But of course speed is not quite all that matters: there are other questions that need to be asked such as how they handle in crosswinds, whether they're stiff, whether they're comfortable and practical for riding as well as racing, and whether they stop quickly enough.
One of the reasons why aero wheels have got wider over the last 10 years is because aerodynamicists have understood that even if a wheel is very fast at zero yaw, once the wind comes in at a higher angle from the side it 'stalls' as the airflow separates, and becomes more difficult to control as well as slowing down because it's not operating as an aerofoil any more. With a fatter rim and tyre, the airflow stays attached on the 'far' side of the rim at higher yaw angles so that stability (and therefore speed) are massively improved.
The SLR 0's 19mm internal rim width makes it much wider than the older aero wheels from Zipp and Hed, and it's certainly much more stable in gusting crosswinds than those, but a gust from a gateway can still blow the front wheel off its line. It's not alarming by any means, and I was perfectly comfortable riding these wheels in a tight group ride that averaged a modest 18mph, but the fact is that with deep rims the faster you go, the more stable they are. In that sense, they really are designed for when speed is all that matters.
With a tailwind or going downhill when they are going faster and yaw angle is reduced, they absolutely fly. Likewise, riding at 25mph+ in a time trial or a road race a rim of this depth comes into its own.
Until you're going up a very steep hill and your speed drops right off, an aero wheel is still faster than a light one. I didn't notice any weight penalty at all on hills – and 1,620g is still pretty light for a wheelset in any case.
Giant's Dynamic Balanced Lacing spoking pattern, which Giant claims evens up spoke tension under pedalling forces, makes the wheels very laterally stiff with no brake rub at all – and this undoubtedly helps them climb well despite the extra weight over a set of true lightweight wheels. They also arrived perfectly in true and haven't moved a millimetre during the test period.
As for the ride quality, they ran smoothly and didn't clatter and jump on rough roads like some deep-section wheels do. In terms of comfort I found them no different from the shallow-section DT R460 PowerTap rims I had been riding previously.
However, the braking of the aluminium R460 rims was far superior to that of the carbon Giants despite Giant's claims of 'superb braking performance even in the wet': with Giant's own brake pads braking in the dry was good, but the real test for carbon rims comes in the wet and the mud, and I found myself having to grab big handfuls of brake once the muck from the lanes had worked its way into the soft-feeling grey compound.
The pads seemed to get very filthy too, and I found myself silently thanking the good puncture resistance of the GP 4 Seasons (or maybe just good luck!) for not making me get my hands dirty. Having said that, I've ridden carbon fibre rims and pads with worse braking performance.
As already noted, Giant is able to offer well-designed, high-quality products at competitive prices because of its place at the top of the bike industry pecking order. That goes for the SLR 0 wheels. However, I couldn't help noticing that Giant's own SLR 1 wheels are considerably cheaper for exactly the same rim. The hubs (DT 350) and spokes (Sapim CX Sprint) add 110g in weight but the SLR 1s cost £999.98. That looks like a good way to save £500 and keep the lion's share of the performance.
The Swiss Side Hadron Ultimate 485s we reviewed recently were more expensive at £1,950, but lighter with a slightly shallower rim depth.
The Giant SLR 0s, however, are cheaper than the (also slightly shallower and lighter) Miche Supertype 440 White Labels.
Competitor wheels of similar depth that we haven't tested at road.cc include Roval CLX 64 (£2,000), Enve SES 5.6 (£2,600), DT Swiss ARC 1400 DICUT 62mm (£1,674.98), and Mavic Comete Pro Carbon SL UST (£1,800).
Hunt's 50 Carbon Wide Aero wheelset at £849 is a popular choice and one often seen on the UK racing scene. Wiggle/Chain Reaction's own-brand Prime Black Edition 50 wheels are also well priced at £1,099.
Meanwhile, the Ican Aero 50 at £500 is one of the cheapest out there – but didn't review well with us for stiffness, crosswind stability and braking.
So for value, the Giants are pretty good considering they use high-end DT hubs and spokes and a proprietary (as opposed to open mould) rim, and bearing in mind their top-notch build and performance. There are cheaper wheelsets, but shortcuts in terms of materials and quality might have been taken to get to that price point.
Superfast, high-end, competitively priced wheels that are perfect for racing or time trialling
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road.cc test report
Make and model: Giant SLR 0 65mm Carbon Wheels
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?
Giant says: "The SLR 0 65mm carbon clinchers are designed for when speed is all that matters. The ultralight carbon fibre rims have excellent aerodynamic properties to cut through the air and make the most of every watt pushed through the pedal. The unique Dynamic Balanced Lacing (DBL) technology gives excellent stiffness and power transfer, especially under extreme force such as sprinting for the line. Designed in conjunction with SLR brake pads to give superb braking performance even in the wet."
For me that description is accurate, but I didn't quite agree with Giant's claims for the braking performance in the wet.
Tell us some more about the technical aspects of the wheel?
Here's Giant's list of 'features':
Aesthetics /Color: UD composite rim / Black hub
Wheel Size: 700C
Ultralight full carbon composite
Rim Type: Clincher
Tubeless: Tubeless Ready with supplied rim tape and valve kit
Rim Height: 65mm
I was really impressed with the construction of these wheels. They arrived (and will leave, I have no doubts) perfectly in true. The carbon is great throughout, and the hubs ran beautifully smooth from day one.
These are very laterally stiff wheels: a deep-section rim is usually stiff anyway, but the spoking pattern (Dynamic Balanced Lacing, a clever system designed to balance spoke tension under pedalling forces for a stiffer, more efficient ride, according to Giant) kept the rims away from the brake pads even when set very close. Naturally that means acceleration is quick, and climbing out of the saddle feels highly efficient despite the slight weight penalty of the deep rim.
These poor wheels have been subjected to some truly nasty conditions. I had to feel sorry for them. However, despite very dirty brake pads I can't see any wear on the brake track yet. As mentioned, they've also stayed perfectly true despite bashing through a flooded pothole or two.
1,620g is pretty good for a wheelset with a 65mm rim.
Expensive on the face of it, but cheaper than equivalent competitor wheels. Obviously not as cheap as open-mould wheels sourced from China but you're paying for Giant's own rims and high-end DT Swiss hubs and spokes.
Did the wheels stay true? Any issues with spoke tension?
They stayed completely true with spokes perfectly tensioned throughout.
How easy did you find it to fit tyres?
Continental Grand Prix 4 Seasons went on with thumbs only, but as detailed above, there was an initial low spot because of the tubeless-ready rim design.
How did the wheel extras (eg skewers and rim tape) perform?
All top-quality items included in the box. Giant's rim strips are in place for clinchers, but rim tape and valves are supplied for tubeless. QRs are good quality but not the lightest available.
Tell us how the wheel performed overall when used for its designed purpose
Giant says this wheel is for when speed is all that matters and that is accurate. They are best for being ridden fast, in road races or time trials. They can do slower riding, but even though the rim is well designed to minimise the effect of crosswinds, it is still more affected by gusting at lower speeds than shallower rims. Not a criticism but something to be aware of if you don't have experience of riding deep rims in all conditions.
Tell us what you particularly liked about the wheel
It's a superfast wheel that, as Giant says, is designed for speed. And it looks awesome too.
Tell us what you particularly disliked about the wheel
There was nothing I particularly disliked about it. Braking in the wet wasn't great, but find me a carbon brake track that does stop well in the wet. That's what disc brakes are for.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
It undercuts similar high-end wheels from Roval, Enve, DT Swiss and Mavic.
Did you enjoy using the wheel? Yes
Would you consider buying the wheel? Yes
Would you recommend the wheel to a friend? Yes, but I might recommend checking out the Giant SLR 1 65mm, which are £500 cheaper, have the same rim but are 110g heavier because of a different hub and spokes.
Use this box to explain your overall score
For racing and time trialling this is a great wheelset – aerodynamic, stiff, responsive, much more stable than wheels of this depth used to be, and running on top-quality hubs and spokes. I've had to deduct a couple of marks, firstly because even though Giant says these wheels are for when speed is all that matters, you've got to be able to stop and their braking in the wet is not quite at the same level as the rest of their performance, and secondly because clincher tyre beads don't seat in the tubeless rims as readily as they do in other brands' tubeless rims.
About the tester
I usually ride: Racer Rosa custom alu My best bike is: Colnago Master Olympic
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: time trialling, commuting, touring, club rides, sportives, school run on a tandem
Simon finished his Masters in online journalism back in 2003 when the internet wasn't very exciting or popular yet. So he got a job as a sub editor on Britain's biggest weekly cycling magazine, where as well as taking out commas and putting them back in again he got to review a lot of bikes and kit.
As a keen time triallist he has spent many hours riding up and down dual carriageways early in the morning and has a national medal, a 19-minute 10 and a few open wins in his palmarès.
He and his seven-year-old son do the school run on a tandem, beating the traffic in car-choked Reigate and getting a great workout at the same time (for one of them).