IRC’s marketing for the Formula Pro RBCC would have you believe that it’s the ultimate race-ready tubeless tyre. Not only is it touted as the firm’s most tenacious tyre in wet and dry conditions, but also for its puncture resistance, ride comfort, and low rolling resistance. That sounds like the holy grail of tubeless tyres, but can it possibly live up to the hype?
As a big fan of IRC’s Formula Pro X-Guard tyres – which I reviewed last year – the RBCC are an appealing prospect. They forgo the bead-to-bead puncture-proof belt of the X-Guard, which trims a modest 20-25 grams of weight per tyre, and that omission also promises a more supple carcass which should pay dividends for both grip and rolling resistance out on the road.
Widths and weight
You can take your pick of 23mm, 25mm and 28mm versions, but in contrast to some manufacturers, IRC intends these to measure true to size on wider rims.
On our 21mm internal width Kinlin rims, the 25mm RBCC measured at 26mm, and on our 19mm internal width H Plus Son Archetypes, they measured just a whisker over 25.5mm.
Buy the IRC Formula Pro Tubeless RBCC tyres from The Cycle Clinic
This is good news for bikes with tight clearances, or for those of us that want to fit mudguards with a minimum of faff.
Weight isn’t in the class-leading territory (in fact, Hutchinson’s recent 11Storm update to its Fusion 5 tyre range narrowly edges it at the weigh-in), but the RBCC is hardly a heavyweight: the three tyre sizes weigh a claimed 255g, 275g and 320g respectively.
That might sound a tad on the weighty side compared to the lightest clinchers, and especially so once you add 30 grams or so of sealant, but it’s more than competitive once you factor in the weight of an inner tube.
Even the most feathery of featherweight clinchers such as Specialized’s 210g S-Works Turbo Cotton and a 75-gram latex tube would only end up being a handful of grams lighter – and those weight savings would be allied to a significant drop in puncture resistance.
Installation
Tyre wear front
Getting the Formula Pro RBCC set up on my pair of H Plus Son Archetype and Kinlin XR 31 RTS OCR rims was fairly routine. The only difference worth mentioning is that the RBCC fit a little less snugly on the rims than the X-Guard.
As a result, two wraps of tubeless tape were required to get them to inflate on the H Plus Son Archetype rims and I had to enlist the help of my trusty high-pressure Airshot to get the beads to snap into place.
As ever, though, the Kinlin rims only needed a single wrap of tape and a track pump – and I suspect the newer breed of tubeless-ready rims will make installation just as easy.
It’s a very minor point, but after a few months of riding, a nasty sidewall slash and subsequent internal repair revealed that the RBCC’s tyre beads are more prone to stretch than their X-Guard-branded cousins.
Where the X-Guards have retained their tight fit well beyond 4000km, the RBCC had loosened a little over the 1700km of riding I had on them, which made them much trickier to reinflate. This is unlikely to affect most people but bear in mind that this may cause you some mild headaches in the event that you decide to swap tyres.
Ride quality
Front tyre
The proof, as ever, is in the riding, and here the Formula Pro RBCC certainly doesn’t disappoint. In fact, the move from a pair of a long-suffering 28mm IRC Formula Pro X-Guards to a pair of 25mm RBCC tyres provided a strikingly different feel out on the road – much more so than I was expecting.
With my 112kg bulk to contend with, I gravitated towards the tyre’s maximum pressure of 115psi. After a few test runs, I settled on around 105psi in the front and 110psi in the rear as the best combination of comfort, grip and speed.
Although I predicted the move to narrower tyres run at higher pressures would be allied to a much harsher ride, this wasn’t the case.
Larger lumps and bumps definitely come through a little more sharply thanks to the smaller air volume of the 25mm tyres, but the Formula Pro RBCC’s more supple carcass simply does a great job of smoothing out rougher road surfaces – arguably more so than it’s more puncture-proof stablemate. Get up to speed, and these tyres glide effortlessly across imperfections and smooth tarmac alike.
Rolling resistance feels dramatically lower, too – and my Strava times certainly bore this out. After fitting the new pair of tyres, I immediately found myself snatching PBs on well-trodden local loops, and holding speeds north of 30kph just felt that little less taxing than with the tough-nut X-Guards in place.
When a puncture repair forced me to swap out the RBCC for one of my previous 28mm X-Guard tyres, the difference was, even more, stark – keeping up with the weekly chaingang was even tougher than usual, and the rear of the bike felt noticeably more wooden with the X-Guard in place.
It’s the grip which comes as the real revelation, however. The rice-bran ceramic compound (yes, that really is what RBCC stands for) stretches wide across the tyre’s profile, and whether it’s the file tread pattern or the sheer stickiness of the rice-infused rubber, the RBCC urges you to fling the bike faster into corners than is strictly sensible.
Tyre wear on the rear
Where rivals such as the Schwalbe Pro One quite literally tend to come unstuck in wet conditions, the Formula Pro RBCC sacrifices a little rolling resistance in the name of all-conditions composure.
Whether it was hammering around greasy corners on my local chaingang loop after a downpour, or just tapping out the miles through roads strewn with all the dirt, flint and hedge-trimming detritus left behind by huge tractors and combine harvesters, the Formula Pro RBCC remain unphased. Frankly, if there’s a limit to their reserves of grip, I don’t want to find it.
Puncture resistance and wear
Durability is a key appeal of tubeless tyres and the Formula Pro Tubeless RBCC certainly seem to deliver on that front.
Whereas I found rivals such as Schwalbe’s Pro One ended up covered in cuts after little more than 500km – and often failed to seal with even smaller punctures – I’ve racked up over 1700km on the Formula Pro RBCC in everything from glorious sun to the foulest downpours.
Only once has the dreaded P word reared its ugly head.
As you can see from the photos below, the tread still looks remarkably fresh and free from cuts and debris. The wear rate isn’t too bad, either, even if my weight has worn off the file tread on the central portion of the rear tyre.
It’s fair to categorise the one puncture as a freak accident: a horsebox forced me off the road and left me skidding through a large patch of shattered crockery embedded in a gravel driveway.
The front tyre emerged unscathed, but the rear tyre picked up a nasty nick in the sidewall which was too large for the Stan’s sealant or my backup tyre worms to cope with.
A tube got me through another 50km of riding and, once home, a puncture patch applied to the inside of the tyre and a dab of flexible superglue on the outer slash restored the tyre’s tubeless properties.
But, sadly, only for a relatively brief spell. It gave way after another 400km of riding at 110psi, and I’ve had to resort to tubes for until I can attempt a repair with a larger diameter tyre worm or similar. I’ll report back if I have any success.
Verdict
As the major manufacturers slowly begin to expand their road tubeless ranges, IRC’s Formula Pro family of tyres finally have some serious competition on their hands.
Some of those rivals, such as Hutchinson’s Fusion 5 11Storm, have convincingly taken the fight to IRC’s trio of tubeless tyres, with lower weights and – as James found in his recent review – impressive all-round performance.
Going by my experience though, those rivals are still going to have a tough time against the IRC Formula Pro RBCC. These tyres are fast, grippy enough for all-season use, hard wearing, and puncture resistant – and while they’re currently a little more expensive than their rivals, this level of tubeless performance is worth paying a premium for.
Buy the IRC Formula Pro Tubeless RBCC tyres from The Cycle Clinic
