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Discussion Starter · #1 ·
This post is simply about the rotational weight difference between clincher and tubular perceved difference while riding on FLAT ROADS ONLY. About to purchase Zipp 404s and to will only move to a tubular system if the difference in rolling speed is noticable. I will be using tubular-clincher if I go clincher version... would the tubular system really yield the faster rolling speed on the flat with its 440 gram lighter rims?.. or is this just on paper?
 

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henry said:
This post is simply about the rotational weight difference between clincher and tubular perceved difference while riding on FLAT ROADS ONLY. About to purchase Zipp 404s and to will only move to a tubular system if the difference in rolling speed is noticable. I will be using tubular-clincher if I go clincher version... would the tubular system really yield the faster rolling speed on the flat with its 440 gram lighter rims?.. or is this just on paper?
According to Zipp the tubular version is under 1300g and the clincher is nearly 1700g! So straight away you have a 400g advantage. Factor in the difference between tubs and clincher-tubs and you've got another 60g+ per tyre so over half a pound difference at the rim end of each wheel.

No brainer!
 

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ultimobici said:
Forgive my stupidity but please explain how 200g+ lees weight at the rim/tyre is a disadvantage?
Tubulars using road glue have ~20% higher rolling resistance than an equivalent clincher. Even on a steep hill that is more important than the weight difference.
 

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rruff said:
Tubulars using road glue have ~20% higher rolling resistance than an equivalent clincher. Even on a steep hill that is more important than the weight difference.
Can you please provide a reference for this? And I guarantee you all the pro teams are not using fastac (sp?) to glue their tires (I've watched up close as they use a brush and a can of standard tubular glue).
 

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henry said:
would the tubular system really yield the faster rolling speed on the flat with its 440 gram lighter rims?
no - for the same power delivered to the crank, steadystate speed on the flats is independent of rim weight.
 

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Can you please provide a reference for this? And I guarantee you all the pro teams are not using fastac (sp?) to glue their tires (I've watched up close as they use a brush and a can of standard tubular glue).
It is interesting that they are using road glue... Do you know any details about the tires?

The data at the bottom of this page is from a test by Tour, Oct 2005:
http://www.rouesartisanales.com/article-1503651.html

Also see here for some older data:
http://bike.terrymorse.com/rolres.html

There have been lots of discussions on the various forums... search for "rolling resistance". Also check here if you'd like to run some numbers:
http://www.analyticcycling.com/
 

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rruff said:
Tubulars using road glue have ~20% higher rolling resistance than an equivalent clincher. Even on a steep hill that is more important than the weight difference.
So your saying that nearly every ProTour team choose to use tyres that are hindering their riders? Pull the other one it's got bells on!

The Tub Advantage
  1. Lighter
  2. Smoother riding
  3. Less prone to pinch flats on poor surfaces
  4. Tend to deflate slower than a clincher (except silks)
  5. Easier to ride punctured
The Clincher Advantage

  1. Lower Rolling Resistance
  2. Easier to repair punctures
  3. Cheaper to repair punctures
I find the 20% figure quoted somewhat suspect. I accept that clinchers may have slightly lower rolling resistance, but on balance they are inferior to tubs in my opinion.

A tub can be ridden at a higher pressure than it's clincher equivalent without compromising ride as much. This is due to the entire air pocket being above the rim. 130psi in a tub is still smooth, whereas 130 in the clincher version is choppy.
 

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rruff said:
It is interesting that they are using road glue... Do you know any details about the tires?

The data at the bottom of this page is from a test by Tour, Oct 2005:
http://www.rouesartisanales.com/article-1503651.html

Also see here for some older data:
http://bike.terrymorse.com/rolres.html

There have been lots of discussions on the various forums... search for "rolling resistance". Also check here if you'd like to run some numbers:
http://www.analyticcycling.com/
I've seen Conti Competitions being used often. I believe some teams also use Dugast tubies (likely relabeled to their sponsor..).
 

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henry said:
This post is simply about the rotational weight difference between clincher and tubular perceved difference while riding on FLAT ROADS ONLY. About to purchase Zipp 404s and to will only move to a tubular system if the difference in rolling speed is noticable. I will be using tubular-clincher if I go clincher version... would the tubular system really yield the faster rolling speed on the flat with its 440 gram lighter rims?.. or is this just on paper?
Wow...it seems like you are confused on MANY levels.

First, while riding on flat roads, there will be NO difference from a rotational inertia standpoint, real or perceived, between a 404 clincher or a 404 tubular wheelset...assuming "equivalent" tires (e.g. Vittoria Corsa and Open Corsa), of course.

In fact, if using a quality clincher (i.e. Open Corsa or Michelin Pro2Race) the clincher version will ALWAYS be faster, despite the higher weight. On flat roads, the extra weight is basically inconsequential. Actually, for the case outlined above (clincher vs tubular 404s with "identical" Vittoria tires) the clincher version actually has an advantage due to it's lower rolling resistance up to and including grades of 9%. Only THEN does the lower weight of the tubular version FINALLY draw even from a performance standpoint. In other words..."on paper", the clinchers are faster.

Now...why in the heck would you limit yourself to running tubular-clinchers on the clincher set? I'm assuming you mean the Tufos, right? Well...that's just shooting yourself in the foot. I haven't seen any RR data on those tires yet, but judging from their tubular tire performance, I don't think they'd be "anything to write home about". This is mostly due to the Tufo's "tubeless" construction where a butyl bladder is built into the middle of the tire. Not a good way to get low RR. If you're going to put that unrealistic limitation on yourself, then by all means go with the tubulars...they can't be any worse.

Of course, if you meant that you'd use "open tubulars" (i.e. clinchers with glued on tread like a tubular) then never mind.

In short, if you get rid of the silly tubular-clincher constraint, the "no-brainer" answer is definitely clinchers. If that constraint stays...do whatever you want since either way you'll be slow...or, at least, much slower than you COULD be.

Hope this helps! ;-)
 

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Weight on flat ground

ultimobici said:
Forgive my stupidity but please explain how 200g+ lees weight at the rim/tyre is a disadvantage?
On flat ground at constant speed it is neither an advantage nor a disadvantage. In other conditions, it may depend on what trade-off the additional weight gives you. If the extra weight buys you lower rolling resistance, the heavier wheels may instead be slower in other situations.
 

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rruff said:
It is interesting that they are using road glue... Do you know any details about the tires?

The data at the bottom of this page is from a test by Tour, Oct 2005:
http://www.rouesartisanales.com/article-1503651.html

Also see here for some older data:
http://bike.terrymorse.com/rolres.html

There have been lots of discussions on the various forums... search for "rolling resistance". Also check here if you'd like to run some numbers:
http://www.analyticcycling.com/
These articles really have my interests peaked. I would like to find a follow-up study mounting tubulars with Tufo Extreme tape. I heard somewhere (don't knw if it's true or not) that it decreases the Crr, but I don't know by how much. I use the Veloflex Carbons so I'm at least in the good clincher category with the "tubular" ride quality. One day, I'm going to do a side to side with the tires I want to choose from (Veloflex Carbon vs. Michelin Pro) with the same setup. I'll probably compare Aeroheads and Escapes which are the most similar. If I don't notice, I just might be won back to the clincher side. My carbon wheels will always be tubular. No all carbon clinchers for me.

-Eric
 

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Discussion Starter · #14 ·
tanhalt said:
Wow...it seems like you are confused on MANY levels.

First, while riding on flat roads, there will be NO difference from a rotational inertia standpoint, real or perceived, between a 404 clincher or a 404 tubular wheelset...assuming "equivalent" tires (e.g. Vittoria Corsa and Open Corsa), of course.

In fact, if using a quality clincher (i.e. Open Corsa or Michelin Pro2Race) the clincher version will ALWAYS be faster, despite the higher weight. On flat roads, the extra weight is basically inconsequential. Actually, for the case outlined above (clincher vs tubular 404s with "identical" Vittoria tires) the clincher version actually has an advantage due to it's lower rolling resistance up to and including grades of 9%. Only THEN does the lower weight of the tubular version FINALLY draw even from a performance standpoint. In other words..."on paper", the clinchers are faster.

Now...why in the heck would you limit yourself to running tubular-clinchers on the clincher set? I'm assuming you mean the Tufos, right? Well...that's just shooting yourself in the foot. I haven't seen any RR data on those tires yet, but judging from their tubular tire performance, I don't think they'd be "anything to write home about". This is mostly due to the Tufo's "tubeless" construction where a butyl bladder is built into the middle of the tire. Not a good way to get low RR. If you're going to put that unrealistic limitation on yourself, then by all means go with the tubulars...they can't be any worse.

Of course, if you meant that you'd use "open tubulars" (i.e. clinchers with glued on tread like a tubular) then never mind.

In short, if you get rid of the silly tubular-clincher constraint, the "no-brainer" answer is definitely clinchers. If that constraint stays...do whatever you want since either way you'll be slow...or, at least, much slower than you COULD be.

Hope this helps! ;-)
Interesting reading and I take your point. Perhaps you could comment on what the advantage is of riding tubular tyes at greater psi say between 160 and 200psi ?.. I have ridden the tufo CElite road tyres at these pressures and actually find them more comfortable on long rides. Are you saying that tubulars have a higher RR the more they are pumped up?.. I have always been under the impression that the higher psi allows the tyre to skim the road with effectively less friction.. do put me right if I'm mistaken. As much as I am unsure of this advantage I am sure that a high psi count helps to avoid punctures....
 

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Discussion Starter · #15 ·
rruff said:
Tubulars using road glue have ~20% higher rolling resistance than an equivalent clincher. Even on a steep hill that is more important than the weight difference.
... are you auggesting also that tubular clinchers have the same -20% RR as regular glued tubs due to their "bladder" (innertube) construction... for tubular-clinchers dont need glue as I'm sure you already know.... ?.....
 

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henry said:
... are you auggesting also that tubular clinchers have the same -20% RR as regular glued tubs due to their "bladder" (innertube) construction... for tubular-clinchers dont need glue as I'm sure you already know.... ?.....
Tubular clincher just plain suck. They're heavy, impossible to repair, hard to carry a spare and offer NO benefit over normal clinchers. They are the worst of the two worlds.

-Eric
 

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Discussion Starter · #17 ·
silly tubular-clincher

Tanhalt.. you mentioned earlier in a brief rat-a-tat-tat with another poster that the glue needed to bond the tub yields a -20% RR penalty compared to a regular clincher.. considering the Tufo tubular-clincher doesnt require glue are you saying that its innertube "bladder "design yields the equivelent penalty??
 

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henry said:
Interesting reading and I take your point. Perhaps you could comment on what the advantage is of riding tubular tyes at greater psi say between 160 and 200psi ?.. I have ridden the tufo CElite road tyres at these pressures and actually find them more comfortable on long rides. Are you saying that tubulars have a higher RR the more they are pumped up?.. I have always been under the impression that the higher psi allows the tyre to skim the road with effectively less friction.. do put me right if I'm mistaken. As much as I am unsure of this advantage I am sure that a high psi count helps to avoid punctures....
OK...well, you asked for it ;)

The ONLY place where it's an advantage for tubulars to be ridden at those high of pressures is on a perfectly smooth track. Even then, that advantage is there ONLY if using an extremely rigid glue (i.e. "track glue"). In any other case, the glue bond of the tubular causes a "fixed offset" in the tire/rim hysteresis losses that no amount of extra air pressure in the tire can change. Look at the left graph here:

http://bike.terrymorse.com/rolres.html

Do you see how the tubular tires RR "levels" off at a higher level than the clinchers, even with increasing pressure? That's the fixed offset that is not affected by pressure.

On normal roads, those types of high pressures you're talking about (160 to 200 psi) will actually cause the resistance to forward movement of the bike+rider system to be higher even though the rolling resistance of the tire may be falling. This is because of all that "skimming" you're referring to. Since the tires are too stiff to effectively absorb the variations in the rough road surface, the vibrations (accels, deccels) are transmitted through the bike and into your hands, feet, and arse. All that energy being absorbed has to be put back into the system by YOU if you want to maintain the same speed.

I don't doubt your perception of more comfort...it's just that human perception is a funny thing...and many times what feels "fast", isn't.

Lastly, high psi does nothing to prevent punctures. It arguably reduces the likelihood of pinch flats...and this is supposedly one of the advantages of tubulars. But, in all honesty, I can't recall the last time (if any) I've pinch flatted on the road. Off-road, yes....but that's a whole different story. I've been told, however, that the supposed lower incidence of pinch flatting with tubulars is more likely the effect of better tubulars using latex tubes which have higher elasticity and are thus less likely to "pinch". That advantage goes away if you use latex tubes in your clinchers (like I do on my race wheels).

Hope that helps!
 

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Discussion Starter · #19 · (Edited)
I'm getting there !... thanks for your time /patience .... but what about the Tufo tubular clincher tha doesnt use any glue ??....
 

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henry said:
Tanhalt.. you mentioned earlier in a brief rat-a-tat-tat with another poster that the glue needed to bond the tub yields a -20% RR penalty compared to a regular clincher.. considering the Tufo tubular-clincher doesnt require glue are you saying that its innertube "bladder "design yields the equivelent penalty??
Umm...actually, I think that was rruff who wrote that. IMHO, he was being a bit kind since the data shows that for tires of the exact same construction except for the rim attachment (Vittoria Corsa CX and Open Corsa CX for example) the tubular can have ~40% more rolling resistance.

You are correct that the tubular clincher doesn't require glue. BUT, since it's made like the other Tufo tires with the exception of a clincher bead molded on, I would expect the tire to perform worse than most other clinchers. I say this because Tufo tubulars, using the same glue interface as all other tubulars, exhibit some of the worst rolling resistance numbers. Get rid of the glue and at best they'll most likely be only as good as an average tubular WITH the glue bond. Of course, all of this is speculation about the tubular-clinchers since I've never seen any RR data on them...but the picture doesn't look promising.

I agree with what Eric said in that "they're the worst of two worlds". The only upside is that they're apparently "bombproof". Then again, if you want that, there are plenty of regular clinchers that would fit that bill with the same middling RR...but they'd be a lot easier to repair and would weigh a lot less too.
 
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