Tire Rolling Resistance Study

[cyclenutnz]

Is it really that hard to set-up 3 or 4 pairs of tubulars for a test? No. No it's not.

If you're trying to do this properly - one wheel so you don't introduce bearing and aero differences into test and preferably same session in order to minimise environmental differences - then yes - tubs are hard to test as you can't go from one to another.

Fractions of a watt? Huh? Like Wiggins during the hour record? Is anyone running clinchers in the TdF to your knowledge?

Track is a different beast - tubs take higher pressures so deal with increased CRR from G-force better. Also the surface is so smooth that there isn't the CRR penalty from overinflation. For road racing there is the tradeoff of better control when flatted and lower weight (for tubs) - usually at the expense of lowest CRR.

I think I heard something about Tony Martin running clinchers in a TT stage once, but it's quite uncommon if it happens.

Tony still on clinchers http://velonews.competitor.com/2014/07/ ... hiv_338580
The reasons for using tubs in Road Races or Track don't apply to TT.

Tyre choice is very much about deciding where you want to compromise. For WW - clinchers are a weight penalty that is hard to bear. Most of my clients I recommend GP4000SII because they're safe and most people doing centuries or Ironman would rather err on the side of tougher than fastest.

[BrianAllan]

Is it really that hard to set-up 3 or 4 pairs of tubulars for a test? No. No it's not.

If you're trying to do this properly - one wheel so you don't introduce bearing and aero differences into test and preferably same session in order to minimise environmental differences - then yes - tubs are hard to test as you can't go from one to another.

If you’re testing rolling resistance, then you don’t need to account for aero-dynamics. If you’re concern is about bearing drag, then you just select a wheelset using the same hub. This really isn’t a challenge. Most of the major manufacturers who have tubular and clincher models are using the same hub between wheelsets. Again, not much of a challenge.

[bm0p700f]

The time taken to glue up a set of tubs properly would make doing the test more time consuming also getting the glue layer the same thickness would be hard and the strength of the bond affects Crr so the test could even invalidate itself with this had to control error.

Beside this is a clincher test not a clincher vs tubular test.

[BrianAllan]

The time taken to glue up a set of tubs properly would make doing the test more time consuming also getting the glue layer the same thickness would be hard and the strength of the bond affects Crr so the test could even invalidate itself with this had to control error.

Beside this is a clincher test not a clincher vs tubular test.

Fine. They could have used tape to have a consistent glue thickness across multiple wheelsets.

Your last point is just silly. It’s a test talking about rolling resistance at 40kph at 270-350 watts. Firmly placing it in the realm of racing. Most people that care about 3 watts are racing on tubulars.

[davidalone]

The time taken to glue up a set of tubs properly would make doing the test more time consuming also getting the glue layer the same thickness would be hard and the strength of the bond affects Crr so the test could even invalidate itself with this had to control error.

Beside this is a clincher test not a clincher vs tubular test.

Fine. They could have used tape to have a consistent glue thickness across multiple wheelsets.

Your last point is just silly. It’s a test talking about rolling resistance at 40kph at 270-350 watts. Firmly placing it in the realm of racing. Most people that care about 3 watts are racing on tubulars.

not really.I road race on tubulars. I TT on clincehrs. tubulars for better controllability in descending/punctures in the tight confines of a peloton. I'm willing to take a small Crr hit for that. in TTs clinchers are just... faster.

[Tinea Pedis]

Firmly placing it in the realm of racing. Most people that care about 3 watts are racing on tubulars.

Sorry Brian but you keep trotting out this stat and it's simply untrue for the majority below WT level. Australia. Asia. Belgium. Raced in them all and clinchers are the majority. Not as much in Belg but certainly in the first two.

And like David said, when it comes to TTs clinchers are fast taking over. WT level and below.

They (Velonews) hit the growth market, simple as that.

[Calnago]

I see where clinchers would be just as good or better than tubulars for a straightforward TT. Good rim/tire interface (better than tubulars for strictly aero performance). Pump 'em up good and hard, comfort be damned (which is not even a consideration in a tt), and just blast away. For everything else, there's tubulars. And MasterCard, of course.

[bm0p700f]

It not a silly comment Brian. Your are critiquing a test someone else has done by saying they should have tested tubs too. If you want it done better do it your self and spend the time and money it takes.
Very easy to say the author could have done more. Plenty of tyres they didn't test but they have to stop somewhere.

Also given tubulars can be pumped up way higher than clinchers would that not negate the advantages that a clincher might have.

[KWalker]

Teams at the pro level often race on tubulars for safety reasons, not for speed.

[rpenmanparker]

Is it really that hard to set-up 3 or 4 pairs of tubulars for a test? No. No it's not.

If you're trying to do this properly - one wheel so you don't introduce bearing and aero differences into test and preferably same session in order to minimise environmental differences - then yes - tubs are hard to test as you can't go from one to another.

If you’re testing rolling resistance, then you don’t need to account for aero-dynamics. If you’re concern is about bearing drag, then you just select a wheelset using the same hub. This really isn’t a challenge. Most of the major manufacturers who have tubular and clincher models are using the same hub between wheelsets. Again, not much of a challenge.

It isn't necessary to use the same hub for every test run, only to quantify the effect of the hub difference on the results. IOW to run different hubs with the same tire to determine the difference between the hubs. Then factor that difference into the final results. Easy, peasey.

[rpenmanparker]

As for those who've looked at the aerodynamics/windtunnel-tests of tires, I really wonder what the actually fastest tire would be,when aerodynamics and crr is both taken into account... I'd take a bet a Conti 4000 would be riding in circles around a cotton specialized?

Tom Anhalt actually looked at that with data from Specialized. The GP4000 (23mm) does in fact beat the Specialized tires aerodynamically, but the Cotton Turbo pretty handedly overcomes that disadvantage between +/-10° of yaw thanks to its rolling resistance.

From http://bikeblather.blogspot.com/2014/07 ... -town.html:

Unless it is reinforced with interwoven nylon or some other more durable fiber, I won't ride a cotton tubular. The tendency for pure cotton tires to simply explode even at reasonable pressures and even when not being ridden is just plain unacceptable to me.

[BrianAllan]

Firmly placing it in the realm of racing. Most people that care about 3 watts are racing on tubulars.

Sorry Brian but you keep trotting out this stat and it's simply untrue for the majority below WT level. Australia. Asia. Belgium. Raced in them all and clinchers are the majority. Not as much in Belg but certainly in the first two.

And like David said, when it comes to TTs clinchers are fast taking over. WT level and below.

They (Velonews) hit the growth market, simple as that.

I'll concede that I can't attest what the global market uses in elite racing. But but in United States the vast, vast majority of the elite (pro 1/2) are using tubulars. If you'd like to dispute this, then supply some evidence. 8 or so years of racing and I can't think of a single person using clinchers unless they had flatted their tubies. A few people randomly using clinchers here and there is not a significant market segment. Therefore if you're trying to supply a relevant performance comparison (keyword: relevant) you need to supply reference comparison between a few tubular offerings.

I don't dislike clinchers. If they're faster than tubulars, then I think it makes a lot of sense to use them in TT's, where the incurred weight penalty isn't as a significant. However, considering this test doesn't support a performance argument over tubulars, I'm not sure while people are so up in arms. If you like your carbon clinchers, good for you. They're just not really used in elite racing.

[petromyzon]

The fact that Schwalbe and Continental, who have the best tread compounds, refuse to sell tubulars with latex inners to the mass market is a serious handicap to their ongoing use. No-one who is serious about speed is going to give up 4-5 watts. The other, more traditional, open clincher/tubular manufacturers clearly have to get their act together as despite much thinner tread caps and much more supple casings they are getting roasted by the likes of Continental in terms of pure speed. Contis may feel like wood on the road, but if you want to go fast and not flat in the wet there is only one game in town.
Hopeful that Vittoria will have made some progress with their new ranges irrespective of whatever Graphene nanobollocks their marketing department are peddling.

[F45]

I think we can agree that Specialized has the best tread compound.

[bm0p700f]

Conti make tubs for high mileage and that are quite puncture resistant. They are good training tubs especially for winter use. My Sunday club run bike which I use autumn winter and spring has conti gator skin tubs on. I don't care about rolling resistance for these rides all I want is the most relaible tyre there is and this is that tyre.

Is there a tubular version of the specialised tyres.