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Verdict: 
Grippy, high-quality tyres with the advantages of tubeless, though you may find they run best at higher pressures
Weight: 
294g
IRC Formula RBCC Tubeless tyres
9 10

I've been enjoying the benefits of tubeless tyres on my mountain bikes for years and was keen to see how the technology transferred to the road. With the IRC Formula RBCC Tubeless tyres I was certainly getting to test it at the highest level. In many ways these are the best road tyres I have ever ridden, with outstanding grip in dry and wet conditions.

My plan had been to ask road.cc for some tubeless tyres and hope they sent me a nice tubeless wheelset to test at the same time. They didn't, dang it, so it was off to the workshop to bodge a 'ghetto' tubeless conversion on my regular Shimano RS80s.

> Buy these online here

After three days of experimenting with various combinations of tape I finally got them to stay inflated. To save you time, the winning configuration was three layers of electrical insulation tape, ensuring at least one layer got right up under the rim hooks on each side to create a tight seal. (Note that the first thing IRC tells you in the instructions is to use only tubeless-ready rims so following my advice will, more than likely, invalidate your warranty.)

Fitting and inflation were otherwise straightforward, and once the sealant was in and distributed around the inside of the tyre, all was secure and airtight. On the first test run I pumped them up to 110psi, anxious to avoid the tyre rolling off the rim in the middle of the first sharp bend, but nothing untoward happened and I gradually began running them at lower pressures, curious to know whether not having to worry about pinch flats would result in a comfort premium.

Surprisingly, I found the answer was 'no'. At 90psi (IRC's minimum recommended pressure) the tyres felt unpleasantly lifeless and, rather than eliminating road vibration they seemed to accentuate it. It was a sensation I can't explain – my only guess is that the thick casing is less compliant than in a standard road tyre and this becomes more obvious as you make greater demands on the casing's flexibility. Whatever the reason, the feeling went away when I increased the pressure to 100psi, where these tyres really zing.

> Check out our buyer's guide to tubeless tyres here

This is also my first experience of a 25mm tyre over a 23mm. The round-profile tyres sit pleasantly plumply on the rim; and measured with the callipers across their widest point came up at 25.5mm. The large-volume casing certainly holds a lot of air, which is very noticeable in the ride quality. I thought for a while the council had been round fixing the roads, but that was just a dream.

The other great quality in these tyres is the grip. I took them to northwest Scotland for a few days' testing on the steepest, twistiest, wettest, gravelliest, farm-manuriest roads I could find and, honestly, it was all I could do to get them to step out of line. Only when I deliberately braked late and hard into a sharp left-hander at the bottom of a steep hill did I finally coax the back tyre into some sort of skid, and even then it was more of a correction of direction than any cause for alarm. It feels like your brakes have had an overhaul. Most impressive.

> Thinking of going tubeless? Find everything you need to know here

Grip can often be at the cost of something else, most typically lifespan or increased drag. With a few hundred miles on the tyres they still look like new and over the longer term we shall see how they fare. So far there's no sign of cuts or abrasions on the casing, and not a sniff of a puncture.

Regarding drag, I saw no evidence in my Strava stats of a sudden dip in my average speed. I kept notching up the PBs (mostly on the downhills – I don't get many on climbs since I turned 50!) and the smooth ride certainly makes it feel as though you are going quickly and is a great fatigue reliever.

IRC says the grip is thanks to a ceramic compound derived from rice husks, which create microscopic ball-like particles with spreading tentacles that stick to the road. This is then combined with a harder centre-line to the casing which keeps the tyre moving quickly on straight lines. Whatever the science, the results are excellent, and if you are thinking of going down the tubeless route I can recommend these as all-weather tyres par excellence.

Verdict

Grippy, high-quality tyres with the advantages of tubeless, though you may find they run best at higher pressures

road.cc test report

Make and model: IRC Formula RBCC Tubeless tyres

Size tested: 700 x 25

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

IRC rate these as all-condition race tyres.

The RBCC tyre uses ceramic compounds devised from rice, mixed with the rubber, to create a tyre that IRC claims has enhanced grip even in wet conditions.

IRC has lots to say on tubeless tyre technology. The advantages are:

Low rolling resistance

Reduced punctures

Reduced natural leakage

Tell us some more about the technical aspects of the product?

IRC says:

The RBCC rubber compound was developed by IRC.

Rice Bran Ceramic is derived from rice. Rice bran (or the outer husk of an individual rice grain) is ground to a fine powder, mixed with a thermosetting resin, and super-heated. When cooled, the block is pulverized to create millions of porous, ball-shaped structures with semi-rigid fingers extending in all directions. These Rice Bran Ceramic "balls" are then kneaded with the rubber and molded into tires. The spikes which extend from the RBC reach out and grab the uneven road surface for increased traction while the pores will wick water from the road surface to create a larger tire-to-road contact patch.

The Formula PRO TUBELESS RBCC shoulders are layered with RBCC compound for high grip performance and the center tread is composed of hard compound which strikes a balance between wear-resistance, grip and rolling resistance.

NR-TEX(NATURAL RUBBER) INNER AIR SEAL SYSTEM

To bring the advantages of a latex tube to a tubeless tire, IRC developed a new high-elasticity tire liner based on natural rubber which offers lower energy loss, reinforced with silica. Despite being slightly poorer at retaining air than the butyl rubber used for typical liners, air retention is sufficient, especially for tubeless construction.

Rate the product for quality of construction:
 
10/10

These look quality from the packet: no surfeit of flash from the moulds, the bead tidy and the moulding true.

Rate the product for performance:
 
9/10

The combination of high volume comfort and high grip makes for a happy riding experience. I didn't get the hoped-for improvement in comfort at lower pressures, though.

Rate the product for durability:
 
9/10

Great so far, no punctures or signs of tread damage; only 500km covered at the time of writing though, and we shall see how they look after 3000!

Rate the product for weight (if applicable)
 
7/10

As a tyre this is quite heavy, but once the lack of inner tube and inclusion of sealant are taken into account, they are pretty competitive.

Rate the product for comfort (if applicable)
 
10/10

A definite boost in comfort, though not due to running at low pressures. I found these rode best at 100psi.

Rate the product for value:
 
5/10

Haven't tyres got expensive? You do save the price of two inner tubes, mind.

Tell us how the product performed overall when used for its designed purpose

These tyres impressed in their road-holding, puncture resistance and comfort.

Tell us what you particularly liked about the product

Fantastic grip, well made, big air volume, stay securely seated, puncture resistance...

Tell us what you particularly disliked about the product

I found the ride quality at lower pressures disagreeable.

Rather noisy at cruising speed and above

Expensive

Did you enjoy using the product? Yes

Would you consider buying the product? Yes

Would you recommend the product to a friend? Yes

Use this box to explain your score

These are incredibly grippy tyres that you would trust with your life on the worst road conditions. Wet or dry, stopping distance was better than anything I've ridden before. The wide, high-volume casing makes for a comfortable ride and the build quality is excellent. They are quite noisy, though.

Overall rating: 9/10

About the tester

Age: 50  Height: 6'2  Weight: 73kg and rising

I usually ride: Cannondale CAAD10   My best bike is:

I've been riding for: Over 20 years  I ride: A few times a week  I would class myself as: Experienced

I regularly do the following types of riding: touring, sportives, general fitness riding, mountain biking

11 comments

Avatar
rix [162 posts] 1 year ago
0 likes

How easy it was to install them? Did yo have to use levers or hands only?
P.S. For me it took two broken tire levers to install first gen. Schwalbe One tubeless on Pacenti SL23 rims.

Avatar
sparker [7 posts] 1 year ago
0 likes

I've been riding on these for a few weeks & can only agree wholeheartedly. Installation was a no tools affair on my Hunt 4 seasons wheels & they inflated & sealed with a satisfying pop on first attempt, tho I do have an Airshot inflator.

Avatar
macrophotofly [257 posts] 1 year ago
1 like

Sort of disappointed with this review. No experience of running 25mm tyres by Neil feels like he is not best placed to say what is good or bad about a set of 25mm tubeless. I would have preferred someone to review this brand/model who had previously rode on, say, 25mm Conti GP4000's, ....and ideally previously on a different brand 25mm tubeless tyre (e.g. Schwalbe Pro One) otherwise his ratings  don't seem to hold up to scrutiny

How can we be sure this tyre is as good as he says for grip? A standard tubed 25mm tyre which has a larger contact patch than a 23mm could have the same increase in grip he identifed.

The lack of experience here provides more questions than answers. How do they compare for ease of fitting compared to other tubeless? (a key concern for most people considering tubeless)? 90 PSI seems mid-range for even a tubed 25mm, so why does the manufacturer restrict below that? (should the fact that there was vibration at 90PSI have been marked down more - I don't get vibration on a pair of tubed 25mm clincher Contis at 85PSI and they feel more confortable at that pressure too). How much air was lost in a week compared to a tubed clincher tyre (especially as these were marked positvely for lack of lost air)?

The article is otherwise well written but sadly I feel this is really about using tubeless tyres for the first time rather than a useful review of IRC Formula RBCC  tyres

Avatar
bendertherobot [1414 posts] 1 year ago
0 likes

The problem with comparison is you need a like for like. So, yes, Pro One 25c v 4000 v these would be fair. But where do you stop.

But in relation to how easy, how long is a piece of string. I can tell you that Pro One on a Pacenti is easy. I can tell you that Vittoria XG is easy the same wheels but really hard to blow up. And I can tell you that the otherwise easy, it seems, Schwalbe G-One on Pro Lite Revo, my rear at least, is the hardest thing I have ever done, so much so that I bought a new tyre lever doobry. Is that the tyre or the wheel? So a controlled test is a good idea, but remove the control of that wheel and easy fitting is a finger in the air. 

 

Avatar
Morricone [2 posts] 1 year ago
0 likes

I've ridden about 1000 km on a 25 mm pair of these tyres in the past month and I'm very impressed too. Mounting on Pacenti SL25 rims with Stan's tape was very easy but did require tyre levers to push the bead up into the hook all the way around on one side (as per the instructions) before inflating. Sealed up nicely first time using CO2 canister, maintained pressure very well dropping about 5 psi per week but only at the beginning. At 75kg I run 90/95 psi front/rear. Very fast and smooth, great lateral grip, longevity looking fine so far.

Avatar
fukawitribe [1923 posts] 1 year ago
0 likes

Review of tubeless tyres on a bodged rim by someone with no experience with 25mm tyres... not perhaps the pinnacle of objective assessment.

Edit. Oh and please don't even remotely encourage people to ghetto their non-tubeless rims for road tyres - that's stupid and dangerous.

Avatar
Tony Farrelly [2893 posts] 1 year ago
0 likes

fukawitribe wrote:

Review of tubeless tyres on a bodged rim by someone with no experience with 25mm tyres... not perhaps the pinnacle of objective assessment.

Edit. Oh and please don't even remotely encourage people to ghetto their non-tubeless rims for road tyres - that's stupid and dangerous.

No experience of 25mm tyres is rather the point. 

Encouraging ghetto tubeless? Where's that then? We'll just leave adults to make their own minds up about the risks they are or are not prepared to take. 

Avatar
fukawitribe [1923 posts] 1 year ago
0 likes
Tony Farrelly wrote:
fukawitribe wrote:

Review of tubeless tyres on a bodged rim by someone with no experience with 25mm tyres... not perhaps the pinnacle of objective assessment.

Edit. Oh and please don't even remotely encourage people to ghetto their non-tubeless rims for road tyres - that's stupid and dangerous.

No experience of 25mm tyres is rather the point.

 

Fair enough - although for some people who might be interested in buying it could also be useful to compare them to other 25mm tyres, which is going to be tricky here. Edit. Got to start somewhere, but this is a bit of a double whammy that possibly could have had a bit more depth - not that fussed.

Tony Farrelly wrote:

Encouraging ghetto tubeless? Where's that then? We'll just leave adults to make their own minds up about the risks they are or are not prepared to take. 

I used the phrase 'please don't even remotely encourage people' - I deliberately didn't say there was direct encouragement but when someone in a perceived position of authority, trust and/or knowledge spends a paragraph and a half talking about exactly how they bodged a tubeless set-up on a road rim then there is the possibity that someone, even an adult, will be tempted to give it a go. You may not like my criticism of the author but I would hope you might at least put some disclaimer in about what is widely regarded - by manufactureres, users and other journalists - as a bloody dangerous thing to do. 

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fukawitribe [1923 posts] 1 year ago
0 likes

A certain Mr Arthur put forward the case in a (IMO) more measured way here (my italics), although i'd still not recommend it.

Quote:

While it is possible to make a regular clincher tyre and non-tubeless rim tubeless, it really isn’t recommended and could be potentially dangerous. Tubeless tyres are designed to ensure the tyre bead locks securely into the rim so it can dislodge at high pressure, which is something you definitely don’t want to happen. This is the critical element of a successful tubeless setup and is why some companies haven’t developed a tyre yet. So you might get away with regular rims but you definitely need proper tubeless tyres. - See more at: http://road.cc/content/feature/172275-road-tubeless-everything-you-need-...

Avatar
Neil Gander [8 posts] 1 year ago
1 like

Regarding the safety issue, I'd be interested to know what role the inner tube is supposed to play in keeping the tyre on? If a conventional clincher with tube doesn't come off the rim, why should a tubeless? In fact, once the sealant has made its way into the tiny spaces between bead and tape, I would say the tubeless tyre is even more secure under the bead than a conventional clincher.

Avatar
Altimis [46 posts] 11 months ago
0 likes
rix wrote:

How easy it was to install them? Did yo have to use levers or hands only? P.S. For me it took two broken tire levers to install first gen. Schwalbe One tubeless on Pacenti SL23 rims.

Better install them by hands, you risk damaging tubeless rim tape by using tire lever and air will escape quickly . . .

Hard or easy, its depends which rim and bead hook design

I have American Classic tubeless ready wheels, its not easy but not that hard, just follow instruction by American Classic installation manual

At first, I have absolute no idea how to put this pains in ass tight tire on wheels but I finally figured it out, used to took 3-4 hours to seat tire with no success, now I can do it less than 20 mins with a bit effort

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