We want to know how the tyres ride and how fast they are, but this requires two separate methods. The first is simple – we rode them hard for hundreds of miles in all weathers. But tyre speed is about rolling resistance and it isn’t possible to test this with sufficient accuracy on the road, even with a power meter. So, in partnership with Ben Delaney at Bikeradar.com, we sent the tyres to Wheel Energy in Finland, where each tyre was mounted to a wheel, inflated to 8bar (116psi) with an identical butyl tube, and run at 40km/h with a 50kg load on a drum that simulates a real road surface. The machine accurately measures the power required to keep the tyre spinning at a constant speed.
No other tyre here enjoys such a glowing reputation as the 217g GP4000 S2. Not only is it loved by road racers and triathletes for its speed (rolling resistance is 32.0 watts), grip and confident cornering, it’s also cherished by aero wheel engineers because, uniquely, it inflates into an egg shape rather than round, making a more effective combined airfoil with a wheel. This is worth a couple of watts, depending on your wheels, which potentially makes this the fastest overall tyre, especially for your front wheel. Its egg shape benefits cornering grip but slightly alters your bike’s handling, so confident descenders stand to gain the most. It’s 330TPI (threads per inch), the highest here, but its suppleness is only middling. Continental also make the more specialist GP TT clincher, but it’s delicate and wears fast, so for race day only.
Verdict: Fast, grippy and even aero; a legend in its own lifetime thanks to its unique egg shape 94%
If you’re a sucker for a natural rubber sidewall, these 222g beauties will win regardless but you’ll be especially happy to know that they tested fast (32.6 watts). The Turbo Cotton comes in 24 and 26mm widths, so we tested both and averaged the results.
The 24 is ideal for most wider aero rims; only the very widest will integrate properly with the 26 so it’s more the comfort choice. Or you could run 24 front and 26 rear for a happy compromise; the slightly reduced frontal area over a 25 should lend a marginal aero gain, too. On the road, they certainly feel fast. They’re beautifully supple, too, thanks to the 320TPI cotton casing. Most improved over the old Turbo is the grip – now there’s much where before there was little. Wet or dry, they give you confidence. They even seem robust. Shame they’re so costly.
Verdict: Fast, supple, grippy, tough, desirable – in short, they’re great tyres but at a high price 93%
Clement tyres are less well known than the other brands here – the name dates back to 1888 but was absent from the market in Europe for a decade until six years ago and has been gradually rebuilding. The LCV launched last year as the top race tyre and it already has a following – and within a few miles it’s easy to see why. The LCV is fantastically grippy and feels really supple; Clement say they achieve this by varying the thread count through the carcass. The wear rate is good and they’re quite tough for such a light (207g) tyre. However, this was one of
the surprises from the Wheel Energy testing, placing last at 36.1 watts and over 5 watts behind the Michelins. You can’t really tell on the road – this is still a fast tyre and miles ahead of training or mid-range tyres – but for all its great ride quality it can’t offer a reason to give up those watts.
Verdict: Feels great to ride – incredibly grippy and supple – but lags behind on rolling resistance 82%
For their first line of tyres, Zipp focused on making a tyre that inflated to an ideal shape to integrate with the aero profiles of their celebrated and ubiquitous race wheels. With this second generation, launched in 2015, Zipp paid much more attention to rolling resistance, aware that the aero gains of a set of 808s can be negated by draggy tyres. The Tangente Speed is incredibly light at 192g for a 25mm tyre and the lab test showed it to be pretty quick (33.2 watt), if a couple of watts behind the best, but many sacrifices have been made to get it to this position. The wear rate is the highest we’ve ever experienced so you definitely have to save them for race days. They’re fragile as well, seeming the most puncture-prone. Dry grip is really positive but they’re no fun in the wet at all.
Verdict: Light and fairly quick but far too compromised – high wear rate and puncture-prone – to recommend 75%
Vittoria say the Corsa G+ is made significantly faster, grippier and more puncture resistant by its inclusion of graphene technology. There’s no questioning the grip and they feel especially gummy in the dry, giving really confident cornering when we raced them last summer. They’re wonderfully supple, too, and seem quick. At 35.2 watts, the lab test result looks relatively poor but owing to availability the test tyre was a 23. A 25 would have certainly been close to the Specialized and Continental. The Vittorias are the heaviest (238g) of this group – for a pair that’s 64g of rotating (therefore, more crucial) weight gain over the Michelins. Back-to-back, that’s enough
to be tangible on a steep climb if you’re tuned in enough. There’s an even faster Corsa Speed G+ model but it’s fast wearing and puncture-prone, so it’s literally race-day only. This Corsa G+ is much more usable
Verdict: Fantastic ride feel, confidence-inspiring and decent speed but a touch heavy, especially on steep climbs 85%
Michelin make big claims for the Competition version of the new Power 4 range and the tyre really delivers. It’s light (206g) and feels supple, despite a relatively low 180TPI threads per inch count, proving TPI numbers aren’t always a guide to identifying a tyre with a classy ride. Grip in both wet and dry conditions is excellent, with real feel for the adhesion available and that breeds confidence. We also used this tyre for the race wheels grouptest and had no punctures in over 1,000 miles – that’s incredible for a 206g tyre in winter. The Power 4 Competition feels fast on the road and it ‘does the numbers’ in the lab, too, posting the outright lowest rolling resistance figure of 30.9 watts. The Michelins are also the least expensive on test. This is a searing return to form for the French brand.
Verdict: Fastest, cheapest, very light, great feel, excellent grip, durable – a clear winner 97%
Our sister title Bike Radar also put some road bike race tyres through their paces - watch their video below
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