[gibbons]

I have ridden tubulars and clinchers. I am currently using Mavic Ksyrium ES clinchers with Conti 4000S and Edge 45 tubulars with Conti 4000S. I am considering a set of Campy Shamals with Hutchinson Atom tubeless.

You can read about anything on the internet. Some say clinchers roll easier than tubulars, others say the opposite. It's pretty hard to make a comparison. Here are a couple of opinoins:

This is a test of all three tire types:
http://www.conti-online.com/generat...al/downloads/download/tourtest_gp4000s_en.pdf
In it it says that modern folding clinchers are way ahead of tubulars, and the data in the tables shows that the Conti 4000S Clincher and Hutchinson Fusion 2 Tubeless are lower rolling rolling resistance than any of the tubulars. I dunno, maybe that difference is like the difference in wind resistance between being on the flats or on the hoods. Whatever it is, there is still a difference that catches my curiousity. It's interesting, though, that even though this is from the Campy site, they didn't sugar coat their 4000S tubular's higher rolling resistance.

Then there's this review of the Shamal tubeless wheel:
http://www.testrider.com/fly.aspx?layout=videoindex&taxid=81&cid=160&preroll=true
Again, I dunno, maybe the component companies bought these guys to say good stuff. It doesn't seem like it though. But if they are right, and tubeless are lower rolling resistance than clincher, wouldn't that make them the lowest rolling resistance?

I plan to run the Atoms without sealant, and carry a tube and inflator. So considering rotational inertia, they should be about like a clincher and tube. Or a tubular with Tufo rim tape. The big difference will be adding 300gm over my carbon tubular rims, argh! I regularly do climbs that are 7-15%. And I will be losing some aero advantage, but does that matter at 20mph? I dunno 3X (I guess I don't know much). But...I will feel a lot better about being able to fix a flat. My son and I have had tubular punctures that wouldn't seal with PitStop or Stans, and needed to call in a ride home from the momma... that would bed a serious issue on a mountain ride where there isn't cellular service.

And, if the tubeless roll smoother, that will be an added advantage. I guess I will see how it all works out when I put them on.

 

[asgelle]

It's pretty hard to make a comparison. ...

Not really. http://biketechreview.com/tires/rolling-resistance/475-roller-data

 

[gibbons]

Not really. http://biketechreview.com/tires/rolling-resistance/475-roller-data

Yeah, it is, especially when resistance ranking data on this site contradicts data from the site posted by Conti.

 

[Cpk]

I will be interested on how the Shamal's work out for you

 

[asgelle]

Yeah, it is, especially when resistance ranking data on this site contradicts data from the site posted by Conti.

So look at the quality of the protocol and data and decide what are the most reasonable results.

 

[gibbons]

Nothing much listed for the tests linked on the Conti site. It says they were done on the Conti equipment, I would hope that their equipment and procedures are reasonably sophisticated! Even if not, I am not looking at the emperical data, I am looking at positions in the list, which are transposed. It's not very confidence inspiring.

 

[gibbons]

I will be interested on how the Shamal's work out for you

I can't tell if that's sarcastic or not, since there are so many opinions here! Is there something about Shamals I should know?

My 160lb son (same lb as me) has a set of the gold clincher-only version and loves them.

 

[Hank Stamper]

Sounds like you're obsessing over differences that have no meaningfull real world relevance.

 

[gibbons]

Sounds like you're obsessing over differences that have no meaningfull real world relevance.

I know, I know, but I like to obsess. I remember putting Conti Gatorskins on my wife's bike for the supposed extra pucture protection. I later had to borrow her wheels, and the extra rolling resistance of the tires made if feel like I was riding in sand. Having been enlightened, I decided that lower rolling resistance (if there really was any) was more important than pucture resistance for her. I yanked them and put on 4000's. I do think I can feel a difference, but how minute, I don't know!

 

[rruff]

What you were probably noticing with the Gatorskins was poor ride quality, which is not the same as rolling resistance.

For the same casing, tubulars and clinchers have about the same Crr if the tubular is very well glued... else the clinchers are better. The tubeless tires currently available have pretty high Crr, which makes them slower than comparable clinchers with latex tubes.

The tubeless tire have no benefit at all unless you plan to use sealant in them... in that case the sealant will work better than it will in a tube.

 

[gibbons]

For the same casing, tubulars and clinchers have about the same Crr if the tubular is very well glued... else the clinchers are better. The tubeless tires currently available have pretty high Crr, which makes them slower than comparable clinchers with latex tubes.

The tubeless tire have no benefit at all unless you plan to use sealant in them... in that case the sealant will work better than it will in a tube.

I am not bashing your opinion, just pointing out that there are a lot of opinions out there! What you said is completely contrary to what the testrider.com (linked above) review said. And making that comparison, I am not saying that they are the experts, either. We need a government agency set up to do the testing

 

[rruff]

I am not bashing your opinion, just pointing out that there are a lot of opinions out there!

That's why it's better to go by facts rather than opinion.

1) Rolling resistance must be tested in the lab or very precisely in the field. You won't feel it unless the difference is huge.
2) The available tubeless tires have been tested to have higher rolling resistance than a lot of clincher tires with tubes.
3) Tubes do not slide against the tire casing... if they did, we'd have tires full of rubber powder.
4) Latex tubes are highly resistant to pinch flatting and add essentially nothing to the hysteresis losses... ie you can get a tire and latex tube that is faster than current tubeless and you can run low pressure if you wish.

 

[asgelle]

That's why it's better to go by facts rather than opinion.

Don't you find it strange that the OP refers to the information presented by Al Morrison as opinion?

 

[jwp3476]

Not really. http://biketechreview.com/tires/rolling-resistance/475-roller-data

"Crr values are typical for very smooth surfaces - Crr on typical road surfaces may be 50 to 100 % higher
Tire Pressure = 120 psig unless otherwise noted"

Hmmm.... What is the Crr value for the chip-seal that most of us have to ride on?

My issue with this "study?" is that all tires were tested on a smooth surface with 120 psi. I have to use at least 125 psi to avoid pinch flats with clinchers but only need 85-90 psi for tubulars. How does that fit into the model? Also, at 85-90 psi the ride is much better.

 

[rruff]

I guess the OP like a lot of people, has a hard time judging what to believe. The bike industry is rife with bogus claims. The testrider site is obviously a sales tool... they made a much better ad than Campy or Hutchinson could. That's where the money is... selling expensive "new" stuff.

$1700 aluminum-rimmed clinchers that weigh 1400g? Why did my 1267g wheelset (with better components I think) cost half as much?

 

[asgelle]

"Crr values are typical for very smooth surfaces - Crr on typical road surfaces may be 50 to 100 % higher
Tire Pressure = 120 psig unless otherwise noted"

Hmmm.... What is the Crr value for the chip-seal that most of us have to ride on?

My issue with this "study?" is that all tires were tested on a smooth surface with 120 psi. I have to use at least 125 psi to avoid pinch flats with clinchers but only need 85-90 psi for tubulars. How does that fit into the model? Also, at 85-90 psi the ride is much better.

Unless you're trying to model performance, the precise Crr value isn't as important as the value relative to other tires under consideration and this won't change with pressure or road surface as long as tires are compared under equal conditions. And since it just got posted again, here's a plot showing how relative position doesn't depend on surface. http://forum.slowtwitch.com/cgi-bin...ring=;guest=110175432&t=search_engine#2922083

 

[rruff]

My issue with this "study?" is that all tires were tested on a smooth surface with 120 psi. I have to use at least 125 psi to avoid pinch flats with clinchers but only need 85-90 psi for tubulars. How does that fit into the model? Also, at 85-90 psi the ride is much better.

Really, you ride tubulars... or do you mean clinchers without tubes? Also you should show a little humility regarding things that you don't know anything about. It isn't a "study"... it's a series of tests that were performed tediously and exactingly over several years and hundreds of hours. And Al has graciously shared the results free of charge or any benefit to himself whatsoever.

On a smooth surface the resistance always goes down at higher pressure. The tests are always performed at 120 psi so that tires can be compared to each other. A tire that has more resistance at 120psi compared to another, will also have more resistance at 90psi. On a real road the ideal pressure (for speed) tends to be in the 90-120 psi range, because there is a break point where vibration losses offset the hysteresis losses. You may prefer an even lower pressure for comfort. And you can use latex tubes if you wish to avoid pinch flats.

 

[cpark]

I have raced with tub/clin since early 80's, and I couldn't tell the difference except the weight difference when I hold it and the slight comfy ride.

 

[cxwrench]

The tubeless tire have no benefit at all unless you plan to use sealant in them... in that case the sealant will work better than it will in a tube.

no benefit at all? how bout being able to run lower pressure and not worry about pinch flats and get better traction? you don't HAVE to run sealant, but i do and i think most road tubeless users do.

 

[Cpk]

no sarcasm, I was looking at them and the dura 1380's among others