Sector GCI Wheelset 700C XD

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.

> Find your nearest dealer here

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.

Value

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.

> Buyer’s Guide: 25 of the best gravel and adventure tyres

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.

Conclusion

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.

Verdict

Tough, interesting looking gravel wheelset that performs well, with a comfortable ride, and will take plenty of abuse