WTB Horizon TCS Road Tyre

WTB's Horizon TCS is a fast-rolling, super-grippy and super-comfortable tyre that excels on the road and is capable of tackling dry off-road trails to inject some adventure into your routes.

Tyres have been getting wider over the years, and this trend for chunkier tyres and a growing interest in gravel and dirt riding on road bikes has given rise to the return of 650B, an old standard once favoured by French touring cyclists because it allowed bigger volume tyres for more cushioning on rough and badly surfaced roads. (By shrinking the rim size you can use the bigger volume tyre.)

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A handful of bike brands big (Cannondale) and small (Hallett Cycles) have been dabbling with 650B and we're seeing a lot more interest from manufacturers of bikes in the gravel and adventure category, where bigger tyres reign supreme. It's all very well having a bike with adequate clearance, but tyre choice is critical.

US tyre and wheel manufacturer WTB is a quick adopter of new trends (it has embraced wide 27.5 Plus tyres in the mountain bike world) and pushed out the Horizon last year. Measuring 47mm wide, they positively dwarf a 28mm tyre – previously considered a pretty wide choice for an endurance bike.

It's a slick tyre, designed primarily for road use, for those cyclists who want to maximise comfort on very rough and potholed roads. The outside diameter is roughly the same as a 700x30, so there's a good chance they'll fit many bikes already on the market (with a change to 650B wheels, obviously), and it also means there's very little impact on the geometry. WTB has a handy compatibility guide here.

The tyre is constructed with an Aramid bead and employs the company's Tubeless Compatible System (TCS), and a dual compound tread with a softer rubber on the shoulders for more grip through the corners. There are four grooves along the tyre tread and a very low profile herringbone file tread pattern.

I installed the tyres on a new 3T Discus Plus aluminium wheelset (review on that soon) with tubeless valves and sealant at the first time of trying, and after some experimenting settled on about 30-35psi as the ideal pressure. That seems crazy low if you're used to inflating tyres into triple figures, but trust me, with extra tyre volume comes the need for less air pressure.

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On the road they feel exceptionally smooth. They iron out bumps and holes in the road in a way that no other conventional road tyre I've ever tested does. Almost nothing fazes them, even clattering into potholes doesn't upset the silky smooth ride, and the tyre carcass still feels supple when dealing with sharper impacts.

Away from the relative smoothness of the road, it's surprising just what you can get away with when you point them off-road. Provided it's dry, I was able to tackle all sorts of bridleways, farm tracks, byways, gravel paths – even some tame mountain bike trails in the local woods where I normally take my mountain bike to play on the downhill tracks.

Durability of the tyre has proven to be very good, and even off-road excursions haven't resulted in any punctures or visible damage to the tyre tread. They have a bombproof feeling that positively encourages you to not hesitate in the face of holes and rocks – they can handle it all.

At 522g they're a fair bit heavier than many narrow tyres, but weight isn't everything. At first, especially if coming from a bike shod with 28mm tyres, the weight is noticeable. There's a bit more effort required to build up speed and the weight can be felt through the handlebar – more force is required to initiate turns and they simply aren't as lithe in response as a narrow tyre. But that's to be expected given how chunky the tyres are, and you soon get used to the riding characteristic.

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Are they slower than a conventional road tyre? To a degree, yes. On the occasional 60km commute into the road.cc office, I was only a couple of minutes slower on the Kinesis Tripster AT shod with the Horizon tyres compared to my time on a Specialized Roubaix with 26mm tyres, on a route with plenty of different road surfaces and a few hills.

But an important distinction must be made in the effort required to shove the wider tyres through the air. The wider tyres do present an obvious aerodynamic handicap. Simply put, more effort is required to propel them along the road at high speeds, anything up to fast road bike speeds above 35kph and the power requirement noticeably rises. Drop the pace down a bit and you find the sweet spot of speed and effort level.

For taming rough roads and injecting some dryish off-road trails into your route, with better rolling speed than most 40mm gravel tyres, there's a lot to love about the Horizon. It's a great alternative to a wide gravel tyre if you're not intending to tackle very loose and rough tracks, but want a tyre that is faster over a wider range of surfaces, including on the road, and can provide a bit more comfort.

Verdict

Super-comfortable big-volume tyres with off-road capability