Specialized S-Works Turbo RapidAir Tubeless Ready tyre

Specialized's range of tyres has come a long way and the company is now investing heavily in tubeless. This new S-Works Turbo RapidAir, developed for the pros, offers easy fitting and very good performance.

The Turbo RapidAir is aimed at racing cyclists who crave the best performance possible. It has been developed with the Deceuninck–Quick-Step team, first being used in anger at the Tour Down Under last year and then Fabio Jakobsen rode them to a stage victory at the Tour of California.

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The tyre has been designed to provide lower rolling resistance and better cornering than the Turbo tubular tyre that the pros commonly use. Specialized claims it's the fastest, lightest and most puncture-resistant tyre it has ever made.

Specialized has constructed the tyre with a 120tpi casing and has sought to reduce the number of overlapping casing layers, to increase the suppleness. It uses two thin plies that overlap at the sidewall, which it claims helps the tyre to "roll 10% faster and grip better than tubular". The beads are wrapped with butyl, there is a BlackBelt puncture protection layer, and familiar Gripton compound over the top.

The new tyre comes in just two sizes, 26 and 28mm, a limited range compared with rivals but likely because that's all the pros will regularly use. We'd expect Specialized to increase the range, down the line.

Actual weight for a 26mm tyre is 267g. That's very impressive for a tubeless tyre – they're typically weightier than their clincher counterparts. For comparison, a 25mm Continental GP5000 TL comes in at 302g.

The tyres feel fast – certainly as fast the current crop of very good high-end race tyres in tubeless and clincher form I've been riding recently, such as the new Michelin Power Road, Goodyear Eagle F1 and Continental GP5000 in clincher and tubeless.

Specialized provides its own testing data, which we can only take at face value, showing the new RapidAir having lower rolling resistance and better cornering than its S-Works Allround tubular. It says the new tyre requires 2.8W less at 40kph and 7 bar (101psi) with 45kg of load on the tyre. Look, here's a tasty graph:

What about independent testing? road.cc doesn't have the facility to lab test tyres (as much as I would love to be able to do that) but UK outfit AeroCoach has tested the new RapidAir. It tested the tyres on rollers, measuring power output and speed, recording atmospheric conditions and bike/rider weight, and repeated the testing over several days. The RapidAir fared worse in the power required to overcome rolling resistance at 45kph compared with two key rivals it tested, the Continental GP5000 tubeless and the Vittoria Corsa Speed tubeless, which topped the table.

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Rolling resistance is only one measure of performance, though; you also need to consider grip and puncture protection, which this testing doesn't cover.

In my experience I've found the Gripton compound, as used for the regular Specialized Turbo Cotton tyres that I hold in high regard, to offer a very confidence-inspiring level of traction in all conditions, whether it's pristine dry roads or damp and mucky lanes that are typical of this time of year.

Braking traction into corners feels good, and traction on steep climbs when you're forced out of the saddle with your nose on the front wheel is also very good. Aim for maximum lean angle in the corners and the tyres continue to impress, providing the reassurance that they aren't going to suddenly let go.

The combination of tubeless sealant and the BlackBelt puncture protection band appears to be a winner: I experience no flats during testing.

The flat-protection benefit is the key attraction of tubeless for regular riders, and while some might not feel the investment or occasional difficulty installing tubeless is worth it, personally I think it's a small price to pay for a massively decreased risk.

> How to avoid getting a puncture

No, tubeless won't prevent all flats, there's a limit to the size of hole that sealant can plug. But since most of my punctures seem to be caused by tiny shards of flint, glass or thorns, which tubeless can easily cope with, tubeless is a no-brainer. If you want to avoid changing an inner tube in the winter weather of pouring rain or freezing conditions, or you don't want a summer race or sportive ruined by a flat tyre, I'd suggest you give it major consideration.

Installation of these tyres onto a pair of Roval CLX32 and Stans Grail S1 wheels was faultless; a regular track pump was all that was required to inflate the tyre. I might have been lucky, and there are still compatibility issues until a worldwide standard is chosen and adopted, but in my experience it seems to be getting easier all the time. With a few squirts of sealant, the tyres remained inflated from week to week with no excessive air loss to speak of.

Specialized provides a compatibility chart with rims from Bontrager, Campagnolo, DT Swiss, Enve, Mavic, Fulcrum, Stans, Shimano and Zipp all listed. You can download it here, along with a handy guide to installation.

I can't comment on long-term durability – I've just not been riding them long enough to determine how they stack up after thousands of miles. Durability in terms of coping with crappy roads covered in debris is good, though – the top of the tyre still looks in great nick.

Specialized also makes its RapidAir Sealant but I wasn't sent any to test, so I used Stan's Race Sealant which I've been using in all my tubeless tyre tests for the past year.

Comfort is good as well, but the 28mm size would be the obvious choice if comfort is a big factor, and with many road bikes now accommodating such wide tyres, unless you're racing, going wider makes a lot of sense.

Rivals

Tubeless has come a long way since Shimano and Hutchinson first collaborated and there have been a few bumps in the road holding back its wider acceptance. The quality of tubeless tyres continues to get better all the time, and with the likes of Specialized ramping up its development and offering/encouraging/forcing its pro athletes to embrace its new tubeless tyres, it's only likely to be an upward trend.

Which is a long way of saying there's a lot of choice now, with most of the big brands offering a tubeless tyre. The Continental GP5000 TL is one of the best tubeless tyres I've tested, and it compares well in terms of performance, though at 302g it's a lot heavier. While the Conti is pricier at RRP, it's now down to about £40. It's also available in a 32mm width option.

Another consideration, and a tyre that showed better rolling resistance performance according to AeroCoach, is the new Vittoria Corsa Speed TLR G2.0. I've yet to test the Vittoria, but Liam reckons it's "fabulously fast and supple".

Conclusion

To sum up, this is a very good tubeless tyre that offers good performance across the board. It's easy to install, it feels fast and grip is good in all conditions, and puncture protection is top-notch. It's also one of the lightest tubeless tyres out there, and for those who place great importance on weight, this could be the tubeless tyre you've been waiting for. In my experience they live up to the Rapid name, though according to one independent test they're not the outright fastest in the market.

Verdict

Lightweight, fast, grippy and easy to install tubeless tyre