, USA 04.2020

Technical FAQ: Tubular vs tubeless tires

Tubeless tires on a tubeless rim with a bead-lock ridge should stay mounted better than most clinchers upon rapid deflation — though still not as well as a well-bonded tubular.

Dear Lennard,
I had reached out after reading your article Technical FAQ road tubeless on February 11th. I’m in the same camp as the old retired guy watching with a sense of reluctance to convert to tubeless, mostly because of the need to fiddle with the sealant and rim compatibility etc., not mention the risk of burping and tires blowing off.

Contrary to what the industry would have us believe, I’m not sure that we have yet to reach a point of carefree riding as a quality clincher with an inner tube. I’m not even sure that the gains in rolling resistance, comfort, weight, etc. are worth the hassle for the everyday rider.

Correct me if I’m wrong: hasn’t the gold standard always been tubular technology for all things fast, light, and ride quality? This is going to sound out of left field, and archaic in my thinking: I was wondering if there been any advancements in technologies with tubulars that would make their everyday use for road enthusiasts a more viable option to a clincher or tubeless setup (in my case Conti 4000sII 28mm at 75psi) to take advantage of the inherent benefits? I have been told that tubulars can now can be taped onto rims, instead of glued? Or would I even notice the difference to what I’m currently riding vs. the cost of converting and hassle?

I’m asking because I was considering giving tubular tires a try this season, and after reading your article, I’m closer, I think, than tubeless. I’m considering this just because I have always heard the ride quality can’t be beaten and the novelty and fun factor of course. My only hesitation apart from the cost of upgrading and the risk of been stranded on the side of the road is the decision on whether to glue or tape them to the rim. Not sure which of these two methods are better in securing them well enough so that they don’t roll off. I ride approximately 5 – 6km per season on a vintage late 80’s lugged frame, strictly road, that I plan to restore. Your thoughts would be appreciated.

I assume the “approximately 5-6km per season” you mention is off by a factor of 1,000 (or, at least 100), otherwise anything I mention would be excessive hassle for riding 20 minutes per season!

Yes, I think it is generally accurate that the combination of ride quality, cornering performance, compliance, and rolling resistance of tubular tires has not been surpassed by clinchers, whether tubeless or tube-type. That said, in this deep dive I took into tubeless performance, you can see that some tubeless manufacturers claim to have surpassed tubulars in rolling resistance as well as in the aerodynamic drag at the rim/tire interface, making them perhaps the world’s fastest tires.

I suspect that if some tubeless tires have truly surpassed the fastest tubular in rolling resistance, it primarily has to do with three things. One is that there can be some loss of energy due to movement at the glue joint between a tubular tire and the rim; this potential energy loss does not exist with clinchers. Another is that energy can be saved by eliminating the inner tube, although this is often more than compensated for by the thicker layer of rubber inside a tubeless tire to prevent air loss. The third is the research budgets of the big tire brands into material compounds for the tread strip being much higher than that of tubular manufacturers. A better tread compound can result in less energy loss in the tread strip due to hysteresis.

There can be little question that the non-vulcanized casing with a super-high thread count of a top-quality tubular will be more supple than any vulcanized casing with inherently lower thread counts (thicker casing threads) that tubeless tires have, and the thin latex inner tube inside of the tubular is unlikely to reduce its suppleness to that of the tubeless tire casing. Casing suppleness means low rolling resistance; the thinner individual threads in the tubular that are not bonded as tightly to adjacent threads are able to deflect rapidly to road surface anomalies and hence not cause the entire wheel, bike and rider to be lifted as much over them, costing more energy. I remain convinced that if the best handmade tubular had the low rolling resistance tread strip of some of the fastest-rolling clinchers and tubeless tires, that it would roll faster than any other tire, save perhaps for a “handmade”, “open-tubular” clincher made of the same materials and construction methods as the tubular, with the same thin latex tube inside and without the glue bond to the rim that perhaps could be costing the tubular some energy.

Yes, the appearance of Carogna tubular-bonding tape has arguably brought the hassle of installing tubular tires on a par with installing a clincher or tubeless tire. I do almost all of my riding on tubulars (right now, on prototype 700 X 40C Strada Biancas), and I greatly appreciate not dealing with glue anymore.

Taping tubulars onto rims is quick; I’m sure I can do it as quickly as I can mount a clincher and inner tube or tubeless clincher. I’m so confident in Carogna tape, even with these giant 40mm tubulars at low pressure, that I’ll probably never again use the many full cans and tubes of tubular glue I have.

Unlike with other tubular bonding tapes I have used in the past, I have found that if I let tubulars sit, inflated, for quite a while after being taping on, my tires are very secure with Carogna tape (I let them sit and bond for a week; that’s probably overkill). I have not tried Eau de Carogna on the base tape prior to taping; I’m betting that would improve the bond even more.

Even in the event of a high-speed blowout and immediate loss of all pressure, a well-glued tubular tire won’t come off of the rim, while some clinchers will. Tubeless tires on a tubeless rim with a bead-lock ridge should stay mounted better than most clinchers upon rapid deflation — though still not as well as a well-bonded tubular.

― Lennard