Sector's GCi wheelset is its new gravel and adventure offering, with a rim that's been created using a recipe of various materials and fibres to produce the characteristics required for riding on rough surfaces. How much of a difference it makes is hard to define out on the tracks, but one thing's for sure: this wheelset performs very well, with a comfortable ride.
Sector has used some interesting carbon fibre technology to create a wheel that it says is 50 per cent more vertically compliant than a standard carbon rim while exceeding the UCI's impact resistance standard by a whopping 75 per cent. Bold claims, though not half as bold as the way they look.
Most manufacturers use one grade of carbon fibre fabric, layered to create the rim and produce the characteristics that the finished wheel and rider will require. Sector does that too, but for the final layer it's used TeXtreme, a spread tow fabric created from a mixture of Toray T700 carbon fibre and Innegra S.
Spread tow carbon fibre is where the individual tows (like a yarn) of carbon fibre are made very flat by being spread, so you get more of a chequerboard effect, and that is what gives the Sector wheels their distinctive finish. That's the natural look of the carbon fibre hybrid, and not a decal like I thought at first glance.
The benefits are that spread tow fibres can be made into thinner laminates, with the straighter fibres reducing crimp (the 'waviness' of the fibres as the strands are woven over each other) which strengthens the composite layer.
Adding Innegra to cycling products is something I've seen before, on the recently reviewed Orro Terra C gravel bike, where it's integrated with the carbon fibre in strategic places around the frame to protect it from being hit by stones and the like flung up from the wheels.
Innegra is a tough, durable olefin fibre (a synthetic fibre made from polypropylene, in this instance) that is one of the lightest on the market, so the theory is that you can add strength without adding weight.
In the lab, the GCi rim was able to handle impacts of almost double the standard required for mountain bike wheels by the sport's governing body, the UCI: it withstood an impact of 140J compared with the UCI stipulated requirement of an 80J impact, making it 75% stronger.
Sector also says that in testing, the GCi rim was 50 per cent more vertically compliant than a unidirectional T700 carbon rim of the same profile when loaded with a 100kg weight.
So, how does all this feel out on a ride?
Well, this is a very nice set of wheels. Sector says the addition of the Innegra takes away the harshness that you find on many carbon rims, and it is true that these offer a beautiful ride, though I have ridden other carbon wheels that feel very similar, from Hunt and Scribe to name just a couple.
Even with various tyres inflated to the upper level of what is really comfortable on gravel, the GCi wheels take out a lot of the vibration and buzz, allowing you to concentrate on the feedback from the tyres.
With a 38mm-deep rim they are quite a bit deeper than many gravel wheels, and while there isn't much of an aero advantage they do seem to roll very well, especially on the stretches of road linking sections of gravel.
Our set of wheels weighed in at 1,730g, which includes the tubeless rim tape fitted: not superlight but not heavy either, and in use they actually feel quite svelte. On the climbs they are responsive – not once did it feel like the Sectors were slowing me down on the steep sections.
Durability looks to be pretty impressive too. A lot of the gravel tracks I ride are military byways that are used for moving huge vehicles around the vast training area, like tanks and lorries carrying cargo and troops. The tracks are mostly wide and flowing so you can get some good speed up on the steep descents, but because of the colour of the stone a lot of the potholes can be difficult to see unless they are full up with water.
It becomes a bit of a bunny-hopping challenge, but at 45mph you aren't going to miss every one and I clouted a few over the test period, mostly with the rear wheel. I'm happy to report that it has stood up to the job, as has the front, with no issues in trueness.
For a tough gravel wheelset, a build of 24 spokes front and rear might seem quite minimal, but everything seems to be up to the job.
Again, how much tougher they are than a standard carbon rim is hard to say over a test period of a couple of months, but Sector is certainly confident. It offers a free rim replacement if you damage it in the first two years, and the rims are guaranteed against manufacturing defects for the lifetime of the product.
The hubs have seen one hell of a lot of rain, floodwater and grit, and taking them apart for a clean and general poke about sees that the seals haven't let in any of the elements, and the RevoCream bearings are still spinning just as smoothly as they were at the start of the test period.
The freehub has 6 pawls with a total of 72 teeth to engage with, which means that you are going to get less than 5 degrees of float before drive is locked in. Ideal when you are on a technical trail flipping between freewheeling over rocks and roots and then needing instant drive to get the power down for a sharp incline.
Freehub options are either Shimano HG or SRAM XDR like we have here.
Tyre fitment was no problem either. With an internal rim width of 24mm (31mm external), fitting a selection of 40mm gravel tyres tubeless was a doddle. In the pack you get tubeless sealant and valves plus the tape, so you are all set up ready to go.
Using a standard track pump, the tyres popped under the bead securely and I got a good seal all the way round right from the start.
Although not cheap, the £1,100 price tag doesn't seem too bad when you take into account the performance and build quality.
As always, you can go cheaper.
Mike absolutely loved the Hunt 35 Carbon Gravel Disc X-Wide wheelset, which has similar dimensions to the Sector. The Hunts are about 140g lighter, though, and a couple of hundred quid cheaper.
The GCi wheels do stand up well against something like the Bontrager Aeolus Pro 3V TLR wheels, though. Again, the Bontragers are lighter by over 100g, but they are an extra £99.98.
If the durability claims made by Sector turn out to be true, their longevity over other rims could increase their value per mile ridden. It would be interesting to see how they perform from a long-term point of view.
I'm a big fan of how the Sector GCi wheels perform, whether on the gravel or road. The ride quality is great, they aren't slowed by their weight, and what I've put them through shows that they are well built.
I wasn't a fan of the way they looked, originally, but when you've got a tyre fitted and they are on the bike it all seems to work. It's a good conversation starter, too.
Tough, interesting looking gravel wheelset that performs well, with a comfortable ride, and will take plenty of abuse
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road.cc test report
Make and model: Sector GCI Wheelset 700C XD
Size tested: Rim: 38mm deep, 24mm internal, 34mm external
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?
Sector says, "The Lightweight Adventure and Gravel Wheelset with a Suit of Armour.
"Whether you're spending long days in the gravel, loading your bike up on an adventure or racing cross in the mud, the GCi wheel-set has your back. Designed to excel in high impact environments, our Innegra equipped carbon rims can shrug off the hardest of hits. The GCi gravel bike wheelset is tough enough for rim strikes on challenging terrain yet light enough for 'cross racing all winter long."
The GCi wheels are a pleasure to ride on the gravel and seem to offer plenty of durability.
Tell us some more about the technical aspects of the wheel?
Redefining Carbon Wheels.
Ride without fear - thanks to the addition of TeXtreme® Innegra into the layup of our rims, we've developed a rim that has 75% higher impact resistance than standard carbon rims of the same profile*. The GCi carbon wheels are significantly more resistant to wear and tear and less prone to catastrophic failure.
Our Innegra™ equipped GCi rims also have 50% more vertical compliance than standard carbon rim**. As a result they exhibit high energy absorption and superior vibration damping, with none of harsh stiffness associated with carbon. These are lightweight carbon wheels, that have the sought-after ride characteristic of an premium alloy wheelset.
Durable Doesn't Have to Mean Heavy.
At just 1690g, GCi is a lightweight, reactive and durable 700c wheelset that can handle a beating. Now you can forget about protecting your wheels and concentrate on finding your flow in challenging trail conditions.
*When compared with same rim shape manufactured with 100% T700 Unidirectional carbon fibre. The GCi rim exceeds the UCI load test of 100J – and passes a load test of 120 J three times with no fracture.
**In rim only vertical deflection tests compared to the same rim shape manufactured with 100% T700 Unidirectional carbon fibre, the GCi rim deflected 50% more, without failure.
Wheel Size: 700c.
Rim Material: T-700 Unidirectional Carbon Fibre | Outer layer: TeXtreme Plain Weave Spread Tow Carbon Fibre and Innegra S Hybrid.
Spokes / Type: Pillar 1422 Bladed / Straight Pull.
Nipples: Pillar Black Brass DSN.
Hub Rotor Fitment: Centrelock.
Freehub: 6 Pawl | 72t Engagement | Shimano HG, SRAM XDR.
Rim Width: (Internal) 24mm | (External) 31mm.
Rim Depth: 38mm.
End Caps: (Front) 100x12mm / (Rear) 142x12mm.
Extras: Tubeless Sealant, Tape and Valves. 15mm End Caps.
They perform well across the board. Stiffness was impressive, especially under hard efforts, though they don't give any feeling of harshness on poor surfaces.
They've stood up to a lot of abuse over the test period.
Did the wheels stay true? Any issues with spoke tension?
The wheels stayed true throughout testing.
How easy did you find it to fit tyres?
Fitting tyres was simple, and tubeless tyres popped securely onto the rim.
How did the wheel extras (eg skewers and rim tape) perform?
A good quality selection of bits and pieces.
Tell us how the wheel performed overall when used for its designed purpose
They seem to be tough enough to take the abuse of gravel tracks, time and time again.
Tell us what you particularly liked about the wheel
Very nice ride quality.
Tell us what you particularly disliked about the wheel
Not everyone will be fan of the finished look of the outer layer of carbon.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
Hunt has similar wheels like the ones mentioned in the review for a couple of hundred quid less, while others, like the Bontragers I also mention, are a little more pricey for a similar package. Longer term, the added durability of the Innegra could come into play, if it really is as reliable as Sector claims.
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 overall score
A very good all-round gravel/adventure wheelset that has shown itself to be durable over the test period while also delivering on performance.
About the tester
I usually ride: This month's test bike My best bike is: B'Twin Ultra CF draped in the latest bling test components
I've been riding for: Over 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 20 years of road cycling and over 150,000 miles in his legs it's safe to say Stu is happiest when on the bike whatever the weather. Since writing his first review for road.cc back in 2009 he has also had a career in engineering including 3D-CAD design and product development, so has a real passion for all of the latest technology coming through in the industry but is also a sucker for a classic steel frame, skinny tyres, rim brakes and a damn good paintjob.
His fascination with gravel bikes is getting out of control too!