Challenge Criterium RS review

The Challenge Criterium RS is a handmade tubeless-ready road tyre designed for, as the name suggests, road racing.

Built around a supple, 350 TPI (Threads Per Inch) cotton casing, Challenge claims this tyre brings improved speed, grip and puncture protection versus its previous road bike tyres.

In testing, the Challenge Criterium RS impressed highly both in the lab and out on the road.

However, its classic, open tubular construction makes installation tricky, and a limited range of relatively narrow sizes means it lacks the versatility some of its competitors offer.

Challenge Criterium RS details and specifications

The Challenge Criterium RS continues the brand’s philosophy of handmade, unvulcanised tyres.

While Vittoria (a stalwart of handmade tyres) has moved over to high-end vulcanised tyres in recent years, with the launch of the Corsa N.EXT TLR and Corsa Pro TLR, Challenge is sticking to its guns.

The Criterium RS, as already mentioned, is made using a 350 TPI (Threads Per Inch) cotton casing – one of, if not the, highest thread count casings available in its class.

All else being equal, a tyre casing with a higher TPI count – meaning it has more strands of cotton or nylon thread per square inch of casing – should provide a more supple ride quality, because each strand will be thinner and therefore more flexible.

These smaller, more flexible strands are usually less durable and puncture resistant, however. As with everything, then, there’s a trade-off.

For the Criterium RS, Challenge has added a rubber seal to the casing, which it says helps improve air retention and durability without impacting performance.

This makes the sidewalls white rather than classic tan, but, as Luigi from Cars says, “White wall tyres, they say look at me, here I am, love me…”

The Criterium RS is also available with black side walls, but I’m with Luigi – black tyres are boring.

There’s also a new tread compound called SmartPrime, which Challenge claims reduces rolling resistance significantly. Happily, as we’ll come to later, our lab test results appear to confirm this.

The Criterium RS also impresses on the scales. At an average weight of 263g per tyre, they’re among the lightest in their class.

Of course, given they’re a smaller 700x27c size, as opposed to the more common 700x28c, that’s unsurprising.

However, if tyre weight is a concern for you, this is a great option.

At £69.59/$94.99/€83.51, the Challenge Criterium RS is priced towards the cheaper end of the scale in the UK, but pricing varies depending on what territory you’re in.

Here in the UK, for example, it’s around £10 cheaper than the Continental GP5000 S TR (£79.99/$97.99/€79.90), and around the same price as the Michelin Power Cup TLR (£69.99/$99.99/€69.59).

There are just the two sizes available, though – 700x25c and 700x27c – which may feel limiting for some, given the direction of travel for the industry (Tadej Pogačar’s Colnago V4Rs had tyres measuring over 31mm wide at the 2023 Tour de France Grand Depart).

The Challenge Criterium RS is compatible with hookless rims up to 72.5psi/5 BAR, but the lack of larger sizes will likely pose issues for riders heavier than myself (I weigh around 64kg).

This is because tyre pressures of 72.5psi/5 BAR are likely to be sub-optimal for both 25 and 27c tyres on an ETRTO standard, 19mm internal-width rim.

Both Zipp’s and Silca’s tyre pressure calculators, for example, recommend a 75kg rider with an 8kg bike use tyre pressures exceeding 72.5psi/5 BAR with both sizes.

In this scenario, Zipp’s calculator (which is designed to support its range of road bike wheels) recommends choosing a larger tyre size, which unfortunately isn’t an option here.

Challenge Criterium RS installation and tubeless setup

As with previous Challenge tyres we’ve tested, such as the Paris-Roubaix TLR, the Criterium RS tyres proved difficult to install.

All else being equal, fitting tubeless tyres is generally harder than installing clinchers (because tubeless tyres use stretch-resistant beads for an airtight seal on the rim), but these were particularly challenging.

In this case, it appeared to be for two reasons.

For a start, they were simply an extremely tight fit on the Hunt 54 Aerodynamicist Carbon Disc rims I used for testing.

Secondly, the Criterium RS is constructed in a classic ‘open tubular’ style. This means it isn’t pre-shaped and instead arrives completely flat.

After installing them by hand proved impossible, I resorted to pulling the final section of bead over the rims using a Kool Stop Tyre Jack (a very handy tool for stubborn tyres, which helps to pull the tyre bead over and into the rim bed).

However, because the tyre lacked shape, other sections of the bead would pop off if I didn’t brace them against the rim.

Once I eventually got both tyres on to the rim, I then found I wasn’t able to seat them with a standard track pump.

I tried soapy water and removing the valve core, but in the end I had to resort to a dedicated tubeless inflator. Thankfully, a blast from a Schwalbe Tire Booster proved enough to seat the beads.

Once installed, my set of 700x27c tyres measured 27.5mm wide at 65psi/4.5 BAR.

All things considered, this was one of the most difficult tubeless installations I’ve carried out in recent years.

It’s fair to say some tyre and rim combinations just don’t get on, but I’ve fitted many of the latest tubeless road tyres to these rims and none have been so tricky.

Given this, I wouldn’t want to be attempting to install an inner tube in these tyres by the side of the road (in the event of a puncture), so would recommend carrying a tubeless repair kit while riding.

Challenge Criterium RS rolling resistance

The Challenge Criterium RS put in a superb performance at the Silverstone Sports Engineering Hub rolling resistance lab.

For a single tyre, the Criterium RS produced just 12.18 watts of rolling resistance at 30km/h.

Of the eight tyres tested, this put it third fastest – just 0.32 watts behind the fastest tyre, the Pirelli P Zero TLR, and 0.97 watts ahead of the fourth fastest tyre, the Michelin Power Cup TLR.

Challenge Criterium RS ride impressions

Out on the road, the Criterium RS impresses with immediate sensations of speed and grip.

Despite its relatively narrow size, ride comfort was also excellent.

Coming off testing the Specialized S-Works Turbo 2BR (a vulcanised tubeless tyre designed for racing cobbled classics), the difference was palpable – even when noting the Specialized tyre already offers excellent ride feel for its class.

Of course, it’s worth remembering there's a trade-off for this, too.

Even Challenge acknowledges that what you gain in speed, ride feel and low weight, you are giving up in toughness (to a degree).

Nevertheless, for the type of riding the Challenge Criterium RS targets – namely, road racing – its performance is exceptional.

Similar to the Vittoria Corsa Pro TLR, the Challenge Criterium RS has relatively poor air retention, however.

Adding more sealant than usual (60 instead of 40ml) helped, but they nevertheless needed to be topped up with air before every ride to maintain optimum tyre pressures.

For those experienced with latex inner tubes, this likely won’t be a dealbreaker, but it underlines the fact that the Criterium RS is – by design – very much a ‘race day’ tyre.

Challenge Criterium RS bottom line

The Challenge Criterium RS offers exceptionally low rolling resistance and fantastic ride feel, offset by the fact it is very difficult to install.

The question remains, then, is the juice worth the squeeze?

If you love the look and ride feel of a handmade tyre with an ultra-high thread count, the Challenge Criterium RS delivers performance in spades (provided your tubeless tyre installation technique is up to scratch).

On the other hand, there are other tyres in its class that are similarly fast, comfortable and grippy, aren’t such a pain to set up, and are available in sizes more suitable for heavier riders with hookless rims.

Given this, the Challenge Criterium RS feels more of a qualified recommendation.