Fast Tires 2013 - Part 2

This is part two of our 2013 update on the wild world of tires. If you missed part one, it is located HERE.

Our previous segment covered what I consider to be the ‘Big Three’ of road and triathlon tires – Continental, Michelin, and Vittoria. These three brands sell a LOT of tires to our market, and generally set the standard for performance and aftermarket sales volume in mid-to-high-end tires. As an indication of this, our 2012 Slowtwitch Tire Poll showed that the majority of our readers ride one of those three brands.

There are certainly other important brands out there that you should know about. Some of them may focus on the low-end, super-high-end, mountain bike, cyclocross, or OEM spec tires that sit on dealers’ showroom floors. Some are focused on road, and taking a bigger slice of the market share away from the Big Three. In this article, we’ll cover what I consider to be the next tier in market perception and awareness. Keep in mind that none of this assumes or implies anything about a tire’s quality or speed – it’s quite possible that the smaller or lesser-known brands make the best stuff. We’re looking at it from a perspective of ‘How likely is it that the average triathlete knows each of these brands by memory?’


Over the past several years, Bontrager has become a well-established player in road and triathlon tires. When I first started riding, Bontrager was – to me – one of those brands that made me think, ‘Oh yeah – they make tires, right?’ They were what came on your Trek, because Bontrager is owned by Trek. Aftermarket sales seemed to struggle.

That all changed with the introduction of the now well-known Race X Lite Aero TT tire. Along with the Zipp Tangente and Mavic CXR, it is one of the few tires in the world that has been marketed specifically on its aerodynamic merits. Your tire weighs 200 grams and comes in four colors? Well – mine makes mincemeat out of the wind.

The newer version of this aero tire is called the R4 Aero. It stands, in my opinion, as the triathlete’s number one choice from the Bontrager line. Independent testing has shown that it is fast rolling tire (it is tied for 8th place on Al Morrison’s giant spreadsheet, and tied for 4th in the data set of Tom Anhalt, a Slowtwitch contributor). I think Bontrager has chosen conservatively in offering a single 700x22 width – a decision that was likely driven by anticipated sales volume. We would love to see a 650c version of this, and perhaps a wider 25mm option in 700c.

In the realm of ‘standard’ road cycling tires, Bontrager has a plethora of options. You have the 220 tpi R4 road, the heavier-but-cheaper R3, a tubeless-specific R3, the R2, and many more. What does this all mean? To make a long story short, higher numbers mean higher price and lighter weight, but reduced puncture resistance. My favorite tires among these are the R3 standard and R3 tubeless. I think these tires are a clear cut above previous Bontrager tires in terms of general quality. I used a pair of R3 tubeless tires along with a test pair of Bontrager TLR wheels, and was impressed with their ease-of-setup and ability to hold air. The initial installation was tight, but after that, they pumped up easily with a floor pump.

When I spoke with Bontrager representatives about this article, their focus was on an entirely new line, called AW, or ‘All Weather’. It is a replacement for the older RXL line.

What do these tires do well? Who is the customer? That depends on what you want. My take is that they’re primarily training tires, yet all of Bontrager’s marketing materials talk about their speed. These tires have the ‘aero wings’ of the R4 aero. They boast lower rolling resistance than all of their competitors. Interestingly, however, all of the competitors listed are not racing tires, but training tires. It appears that Bontrager is breaking new ground in selling the notion of ‘free speed’ via low Crr to the masses. This is not a puncture-prone race-only tire – it is for the real world. Given that reliability constraint, they want to have the fastest tire out there. I don’t know about you, but I wouldn’t mind a couple free watts against my training partners for our next 100-mile ride.

I was happy to learn that Bontrager put money into 3rd-party testing and, more importantly, are sharing the data. If someone wants to poo-poo this data because it’s being distributed by the manufacturer, go ahead. Maybe it’s false – I don’t know. I just appreciate having something to look at and discuss.

Testing was done by Wheel Energy in Finland. They are a dedicated tire testing facility for bicycles, motorcycles, and ATVs.

The Y-axis is a simple wattage requirement to spin the tire.

Note that the Bontrager tire listed is their lightest and thinnest option among the AW line (the AW3 Hard-Case Lite. This tire replaces the older RXL All Weather, and weighs 240 grams in 700x23 size. It’s certainly heavier than sub-200 gram race-only clinchers, but much less than the standard AW3’s 295 grams. For comparison, a 700x23mm Continental Grand Prix 4-Season weighs 230 grams, and the Gatorskin weighs 280 grams.

This image compares the casings of the AW3 Hard-Case Lite (left) and the standard AW3 Hard-Case (right):

What about tubular tires? Bontrager did not inform us of any changes in the line, so we have nothing new to report for this year.


Challenge continues to break their way into triathlon. Indeed, a new addition to their US staff is Chris Clinton, formerly of Bontrager. For those who may not be aware of Challenge, he offered a quick backstory for me:

“As insinuated on page three of the Fast Tires 2012 article, Challengetech does own their factory in Thailand. The Brauns family purchased the company that was producing Clement tires, refurbished the machinery and restarted existing production lines. The new firm, called Challengetech, was producing Clement tires and private label tires for other brands. In 2003, Challengetech ended a licensing agreement for Clement and began producing tires under their own tire brand: Challenge. [We] continue to produce our own brand, as well as private label tires for other brands. Challengetech also supplies treads and tubes to smaller brands seeking our expertise and production capabilities.”

This begins to answer some questions, at least for me. When I see ‘270’ or ‘300tpi cotton casing’ on a different brand of tire, I always used to assume it was made by Vittoria. But – what if it’s made by Challenge? Clinton tells me that they have the capability to make a variety of thread counts, treads, and with polycotton, corespun cotton, and silk casings. Yes, these tires are the Real McCoy.

For timed individual race events, Challenge tells us that they have two main models – the Triathlon and the tubular-only Crono S.C. The Triathlon model includes the Challenge PPS (Puncture Protection Strip), and is intended for longer-distance events. It is available in clincher (300tpi, 23mm width, 700c only) and tubular (300tpi, 22mm width, 700c only). The Crono tire still includes the PPS, is lighter weight, intended for shorter events, and is available in tubular only (300tpi, 22mm width, 700c only).

Beyond that, I’d call the Criterium model their bread-and-butter race tire, somewhat similar to the Vittoria Corsa CX. It has a 320tpi casing, seamless latex inner tube, and can be had in clincher ($75) or tubular ($110). You can also upgrade to a luxury-only silk casing for the tubular model, bringing the price to an eye-popping $164 per tire. The cotton Criterium has done well on both Al and Tom’s rolling charts, definitely ranking towards the pointy end of the tire field.

For those that prefer a wider tire option, Challenge offers the Strada model in clincher and tubular – both 25mm.

The only Challenge tire I’ve personally used is their 23mm Forte clincher. This tire features a pronounced file tread and is intended for wet conditions. I plan to talk about these tires in detail with an upcoming wheel review, but I’ll say this – they’re nice. I’ve become very suspicious of similar-type high-end tires over the years due to numerous punctures. The Forte has been – knock on wood – flawless so far. I have to wonder if this is due to its 'SuperPoly' casing; most of my flats have been on traditional cotton casings.

Just for a real-world example, my first ride on the Fortes started with decent weather and temperatures just below 50 degrees Fahrenheit… and quickly dropped ten degrees and started pouring rain. I was riding repeats up and down Gold Camp road in Colorado Springs, a steady 3-4% climb that takes about ten to fifteen minutes to ascend. The road was strewn with small rocks and absolutely covered in water, but my tires suffered no apparent ill effects.

As a bonus, this tire tested only 1 watt slower than the super-high-end Criterium, according to Tom Anhalt’s data. In my opinion, that’s a small penalty to pay for what seems to be a big hike in durability.

If I could see Challenge improve upon anything, it would be to embrace triathlon and start offering a few models and sizes in 650c. A 23 and 25mm training tire, along with a 23mm race tire (such as the Forte) would really broaden their appeal. Even if they only did clinchers, it would be a great start.


In 2013, Schwalbe became the official tire of Ironman. Clearly, your sport has piqued their interest.

The above photo is the upcoming Ironman tire model, set to be available in September. The tire is similar to their high-end Ultremo ZX, but comes in 700x22 width. According to Schwalbe engineers, this width offers the best of both aerodynamic and rolling performance with today’s wide rims, which is further boosted by their aerodynamic tread design. It also includes their new RaceStar Triple Compound, said to offer their lowest rolling resistance ever. The Ironman is available in the following options:

Clincher: $85
Tubeless: $100
Tubular: $150

The aforementioned Ultremo ZX is what I consider to be the top ‘normal’ tire in Schwalbe’s line. I’ve ridden it in 700x23mm clincher, 650x23mm clincher, and also its predecessor, the Ultremo R in 700x23. Overall, I’ve found the tires to be outstanding. I’ve never punctured on them, the ride quality is great, and they seem to fit very easily on difficult rims (that last one is perhaps the biggest bonus). The tire even comes in 700x25 and 700x28mm sizes, pulling the trump card that neither Continental or Michelin can in their core race tires.

The ZX is available in standard clincher and tubeless clincher. There is no tubular version of this tire; the rough equivalent is their Ultremo HT (short for Handmade Tubular).

The biggest news for Schwalbe this year is the introduction of their new ONE tire. This tire will be available to consumers in September, and debuted just a couple weeks ago during the 2013 Tour on Schwalbe sponsored teams.

The story here, according to Schwalbe, is that this tire is both more durable and faster than the Ultremo ZX. Due to advances in compounding, the tire boasts a 20% improvement in cut resistance and reduced rolling resistance.

You may find it interesting to hear that Schwalbe claims that their fastest tires are the tubeless models. They were able to quote the ‘watts-to-spin’ metric for a few of their models, but do not publish data for competitors, nor detailed testing protocol. They say that the new clincher ONE tire requires 2.5 fewer watts to spin than the Ultremo ZX – and the tubeless ONE drops another two watts beyond that. If that’s true, a 4.5 watt drop over their standard ‘fast’ tire is significant, especially if the durability claims also hold up.

The final interesting note from Schwalbe is about latex inner tubes. In an email exchange with Schwalbe Media Liason, Sean Cochran, he noted the following:

“We talked a while back about Schwalbe's process of making latex tubes for our tubular tires, and if we would ever [offer] latex tubes for aftermarket sale. At this point, we will not come to market with individual latex tubes because they are easily contaminated – and the contamination can cause premature failures. Something as simple as the oils on your hand can begin to degrade the latex and cause weak spots in the tube. We will continue to use them in our tubular tires because of the rolling resistance and puncture benefits, but don't expect an aftermarket tube any time soon.”

That is eerily reminiscent of why Michelin got out of the latex tube game – they are delicate flowers indeed.


Specialized came out swinging this year – making some big claims. Put simply, they say they have the fastest rolling clincher, tubular, and tubeless tires on the market. While it may seem odd to expect fast tires from a bike company, we don’t have to look too far in the past to see that they have indeed made some fast tires. The now-discontinued Mondo Open Tubular was barely in second place on Al Morrison’s data sheet – by a measly 0.0003 Crr. Specialized has also been hiring some very smart German tire guys who have decades of experience in the tire industry – Wolf VormWalde and Wolfgang Arenz.

The new super-fast tire in the Specialized line is called the S-Works Turbo. For now it is available in 700x24mm width, and they say a 26mm version is coming soon. Why are the tires this wide? Specialized echos what we’re seeing from just about every other manufacturer: wider tires have lower rolling resistance. Specialized provided this graph showing four different widths of the same Turbo Pro tire (28, 25, 23, and 19mm):

How does the new 24mm clincher model stack up against the competition? This bar graph is from the Wheel Energy lab in Finland:

The other interesting note is that – like Schwalbe – Specialized says that their fastest-rolling tires are the tubeless models. This data set comes from Specialized internal testing:

Of course, rolling resistance is subject to the application of tubular glue, inner tube choice, and other details. We have a pair of new S-Works Turbo 24mm clinchers for test and review, and look forward to riding them. It will be interesting to see if independent tests can verify the claims of ‘fastest tire’.

Beyond the top-end tires, Specialized has quite a few options. The Turbo Pro and Turbo Elite follow the usual scheme of lower price, higher weight, and higher rolling resistance. I have a pair of 700x25mm Turbo Pro tires that I’m currently testing with a pair of Reynolds wheels, and they seem to work very well. They measure exactly 25.0mm, and ride nicely at about 90psi.

Outside of that, I like what Specialized is doing in what they call ‘Endurance Road Tires’. Similar to the Vittoria Pave CG tire (24mm or 27mm width) and the Challenge Paris-Roubaix (27mm), Specialized offers the Roubaix Pro. They’ve taken an interesting line and offered two sizes – one called ‘700x23/25’ and another called ‘700x25/28’. It’s an interesting marketing tactic, which I’m guessing others will copy. Whether or not most of us actually do epic rides on cobbled roads is irrelevant – we love the idea of it.

Also, from a practical standpoint, the width of a tire is entirely dependent on the width of the rim. A 700x23mm tire cannot measure exactly 23.0mm on a skinny rim and a fat rim. Maybe Specialized is just taking this into account and measures their tires on a variety of rim widths – and listing the range of resulting widths. Industry: take note!

Similar to my gripe with other companies, the limit with Specialized is 650c. I suppose it should come as no surprise, as their triathlon bikes – even the smallest sizes – feature 700c wheels.


In the next segment, we’ll continue to cover more brands.