Tubeless road tire 2023

This is a common complaint people make about tyres.

What is “Supple”?

RR is inversely proportional to sidewall compliance. The fastest tyres have the most compliant sidewalls because this is how hysteresis loss is reduced. GP5000s are faster than, say, S Works Turbos and they have more grip. In fact, you could run a gp5000 at a lower pressure than a turbo for the same rolling resistance and get even more grip and even more comfort.

My gut says it’s inconsistency when inflating tyres - or incorrectly assuming that “28c” in one tyre is “28c” in another - and so 80psi in a t2/t5 might actually be 90psi in a gp5000 because the 5000 comes up large. This is why the silca calculator asks for measured width not stated width.

Wondering how the staggered setup feels wondering if I should go 30c front and rear or 28c fr, 30c rear on my SL8 Pro with Rapide wheels. 28c would have a little weight and aero benefit but wouldn’t be worth it if it affected handling or made things weird, I understand it would slightly reduce comfort.

I do 28 front 30 rear, and don’t notice any handling issues at all. I’m very happy with the setup.

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I would go 30 or 32 on the front and 32 on the rear.

My 28 is not as wide as the rim and doesnt adhere to the 105 rule

To me, the 26c front on Tarmac SL7 with Rapide CLX (1st and 2nd get) feels a little squirrelly because of road debris. I definitely prefer 28 or 30 or 32 on the front, and the tires are still narrower than the 35mm external rim width.

For me the back tire is more about flat prevention. With the 1st gen Rapide CLX (tube only), I definitely found that 32c tires would get less flats than 28c. With a 28c tube tire, I was getting a flat every 2-3 weeks because our roads are littered with thorns (goatherds) and screws/nails that fall off trucks of constructions workers (this area has seen new housing developments for 20 years).

No issues running staggered, it’s all fun just like my previous car (BMW 535 staggered rims and tires). And as to tire width, I recently set a KOM on a shorter ~0.3 mile / 0.5km segment at almost 32mph on my Checkpoint gravel bike with 42c S-Works Pathfinders. Coming back into town I had a nice tailwind and was holding 29mph for 3+ minutes, but was solo and working for it around 110% threshold. The cool thing was I was floating over the crap road on those big tires, and on the Tarmac the 32c GP5K AS TR also provide a fair amount of float on crap roads at speeds above 22-24mph.

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But you want the tire to be narrower than the wheel for 105.

Doesn’t that rim measure 35mm OD

True, I thought the wheels were optimized for 28mm… I think you would need the tire to blow up to 33.5 to get the rule of 105. Maybe I should just go 30/30. For some reason was thinking 28mm in front would be more aero at the sacrifice of comfort but maybe not with the Rapides…

At launch Specialized stated the Rapide CLX (I and II) are aero optimized for 26c Specialized tires. FWIW I read somewhere that Specialized told a tester (that experienced and reported it) that 26c front on those 35mm Rapide CLX will get pushed around a bit more in crosswinds, while 28c won’t. And then you have NorCal cycling’s non-scientific test where 32c were faster. So “what’s the fastest tire” really depends on real-world aerodynamics, tire/road surface impedance, and the tire’s rolling resistance on that particular road surface. None of which you can predict on a steel drum, so take the BRR testing with a grain of salt.

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Well said. Sums up my opinion on the whole thing.

I would run a 30-32 on the rim. I’m running a 28 Only because I have 4 of of them

Dylan Johnson was on a podcast this past week where he said his fastest tires were 47c tires FWIW.

fastest where? I’d bet he wouldn’t say that if he was on an indoor track or doing a flat 40km TT :rofl: Just saying…

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Just as a heads up, had inquired with Tufo about whether they would be offering their Comtura 4 TR in a 32c or 34c in the future and how the new Endurance 7TR compares to the Comtura 4 TR and when it might be tested by Bicyclerollingresistance.

This was their reply:

‘In future we plan 32. 34 not yet.
Endurance is better in every aspect. It is brand new evolution. Should be tested in 2 months…’

The Comtura 4 TR compares well to Mondo, P Zero 4S TLR and Corsa Pro Control but with better puncture resistance in 28, if it was available in a 32-34c I would be using it as my commuter tire, sounds like the Endurance 7 TR may be even better though!