Clinchers Vs. Tubbies.

[Christie]

Conti, some things in the article sound a bit suspect:

 

"Quite simply, tubular tires have higher tire pressures, and therefore, lower rolling resistance. This also provides them with a more comfortable ride."

 

The harder you pump the tires, rolling resistance may go down, but comfort will also decrease.

Christie2008-03-14 02:38:18

[Conti]

i have no experience on tubbies and i do not know how knowledgeable the author of the article is.

so i am not advocating it, just something to add to the discussion

[ShortLegs]

I rolled a tubby on Belville once!! Not funny...but I managed to keep upright!!

 

And the next time you let Chunky glue your tyres on with pli-bond (or whatever the hell it's called) the kind where you throw away your wheel when the tub is worn

 

All I can add to this debate is personal experience. If you race seriously/semi then my advice is to get a set of tubs with a bomb and some Vittoria flat fix to get you home if you puncture.

 

Bottom line is even if you have a backup vehicle, unless you draft it back to the bunch after changing your wheel, your race is over (hey Nolan).

 

Train on clinchers, the GP4000S are exceptional and the chilli compound will be available across their range of tyres soon .

 

If you need further proof, take your clinchers out for a good hard ride on Saturday and then borrow some tubs and ride the same route on Sunday (don't forget the flat fix/bomb) and you'll be able to give your own informed opinion.

ShortLegs2008-03-14 02:53:10

[Christie]

I think a good experiment would be to do Shortlegs' test, using a set of wheels that come in clincher and tubular, like Mavic Cosmic or Campy Neutrons, so using exactly the same wheelset, one clincer, the other tubby.

 

it would not be fair to compare a set of Bora tubbies to a set of Proton clinchers.

[Johan Bornman]

hier is n artikel oor die onderwerp in die Ultracyling  Magazine.

 

Five Good Reasons Why you should not read bicycle magazines.

 

1) Tubular tires' date=' overall, provide a better ride (there's a reason that more pros use tubulars!). If you want to see verbal gymnastics, ask someone to define "better" or "responsive" in this regard. And no, Muddy, the dictionary doesn't help you out.

 

2) Quite simply, tubular tires have higher tire pressures, and therefore, lower rolling resistance. No tyre "has pressure." Tubulars can survive higher pressure but the benefit of higher pressure disappears exponentially over 100 PSI.

 

3) This [higher tyre pressure'] also provides them with a more comfortable ride. Ja, and a wheelbarrow with an iron wheel provides the most comfortable ride of them all.

 

4) Practically speaking, they also tend to be more puncture resistant, and pinch-flats are non-existent with tubulars because of the very nature of their construction. X mm of rubber is Y puncture resistant. Thickness is thickness, tubbie or clincher. Please note that I acknowledge the pinch-flat issue.<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

5) The performance gap between clinchers and tubulars has decreased in recent years. A good clincher tire performs almost as well as a tubular these days. Almost? How about BETTER? A clincher pumped to equal pressure as a similar tubbie has less rolling resistance unless the tubbie was glued with shellac.

I've head someone tell women that they shouldn't read women's magazines because it makes them fat...or something like that. Well, bicycling magazines make you stupid.

[GreyOwl]

They makes us stupid?

 

 

 

Johan...I'm going to give you a little insight here. Most of the people here that have commented have the experience of actually racing on tubulars.

 

In all fairness (& I believe you are fair) you cannot comment here. You have not raced on tubulars. You have ridden a set that did not belong to you, as you stated.

 

Therefore, we are the 'enlightened' ones here.

 

This is something that could go on, & on,& on.

 

 

 

I accept that you are well versed in mechanical things, and I read most of your postings with great respect and awe. But with your last post I was not entertained, and I really did lose some respect for you.

 

 

 

I'm not stupid, even though I'm a mag reader!

 

But to slate us because of our experience is a little out of line, especially when you are speaking out of inexperience.

 

 

 

 

 

But, I would be interested to hear more about your claim in the 5th point. How can you prove that very point? And why Shellac?

 

 

 

Yours sincerely

 

Stupid Simon "the mag reader"

[Johan Bornman]

They makes us stupid?

Johan...I'm going to give you a little insight here. Most of the people here that have commented have the experience of actually racing on tubulars.
In all fairness (& I believe you are fair) you cannot comment here. You have not raced on tubulars. You have ridden a set that did not belong to you' date=' as you stated.
Therefore, we are the 'enlightened' ones here.
This is something that could go on, & on,& on.

I accept that you are well versed in mechanical things, and I read most of your postings with great respect and awe. But with your last post I was not entertained, and I really did lose some respect for you.

I'm not stupid, even though I'm a mag reader!
But to slate us because of our experience is a little out of line, especially when you are speaking out of inexperience.


But, I would be interested to hear more about your claim in the 5th point. How can you prove that very point? And why Shellac?

Yours sincerely
Stupid Simon "the mag reader" [/quote']

 

Simon, stop feeling sorry for yourself. Cycling mags don't affect everybody equally. I'm sure you are so immune, you don't even get paper cuts for them. Put on your humour hat and smile.

 

 

I think my point may have been crude, but on the mark. People tend to believe everything they read in magazines (and the internet) and that skews their thinking. Have a look at every decent debate on the spanner forum and you'll see that magazine articles are thrown in as evidence. Very few people have the ability to discern between what they just read and the truth.

 

Anyway, point 5.  I think I've explained it several times here and on the previous post I hyperlinked for you. Let me repeat. If you use soft glue instead of hard glue (commonly known as shellac, in the old days), then a tubby has more RR than a clincher. This is because of squirm between the tubbie and the rim. It is evident from the black aluminium oxide at that interface.

 

Take off your rear tubbie (that's worse than the front one) and look for the telltale black stuff that indicates movement between the tyre and rim. Hard glue (and I'm talking rock-hard stuff here) prevents that. Only then does a tubby have less RR than a clincher.

 

[Trackie]

I have ridden tubulars for many years and have yet to experience the "black stuff" of which you speak. Fact is, as you state in your earlier post, pressure is key. I defy anyone to ride a steeply banked track on tyres inflated to less than 12 Bar (yes- I do have personal experience) no commercially available clincher tyre can handle that pressure - yet, 12 Bar is not sufficient for competition - anything less that 15 bar in your tyres at international level- and you may as well stay in the pub.

 Of the questions regarding the use of tubbies on the road - I have limited experience in road racing and will thus leave comment to those in the know.

[GreyOwl]

You believe everything you read Johan.

 

Thats why you continue to contradict what we are saying.

 

 

 

Black stuff? JB I mean no disrespect, and I always have my humour hat on, but where on earth do you get this from?

 

Your in the wrong post here bud.

 

I cant take advice on racing wheels from a man who RIDES in slops. Sorry.

[Craig Smith]

Interesting point on the shellac, when I did woodworking, I used shellac to do a french polish on the timber. All this time I should have been using it to stick my tubbies on. I guess my tubbies will shine nicely now!!!

[Christie]

It seems that other technical guys also know what JB is talking about:

 

From velonews' tech Q&A:

"I do use Tufo tape, but I wouldn?t use it on wheels that must be set up to be as fast as possible. The reason is that test results that I have seen indicate that the rolling resistance is higher with the Tufo tape than with rim cement. This is presumably due to energy loss through hysteresis, caused by the tape squirming around." 

 

http://www.velonews.com/article/73145/technical-q%26amp%3Ba-with-lennard-zinn--tubular-tape

 

The comment was specifically directed at tufo tape vs. glue, but it seems logical that hysteresis behaviour will depend on the stiffness of the glue. A conclusion would be:

 

Stiffer the glue=less hysteresis and=lower rolling resistance.

 

This does not help resolve where RR of clinchers vs tubbies fit in, but leans support to the squirming of tubbies argument.

 

[David #7]

Whats going to happen when we start fitting tubeless on road bikes? I see Hutchinson have clincher type tyres that can be fitted tubeless.

 

Browsing through a Continental broucher they make only one clincher that can be inflated to 170 psi while all the tubbies go up to 170, with 1 track tubbie going upto 220 psi.

[Johan Bornman]

Interesting point on the shellac' date=' when I did woodworking, I used shellac to do a french polish on the timber. All this time I should have been using it to stick my tubbies on. I guess my tubbies will shine nicely now!!![/quote']

 

Yes, the very same stuff. Boiled Shellac beetles. It makes for nice shiny (albeit fragile) wood surfaces. If you've worked with the stuff you'll know that it makes a hard surface, a little bit like the glue in peanut brittle sweats. This is what used to be used on tubbies before contact glue was invented.

 

 

[Johan Bornman]

Interesting point on the shellac' date=' when I did woodworking, I used shellac to do a french polish on the timber. All this time I should have been using it to stick my tubbies on. I guess my tubbies will shine nicely now!!![/quote']

 

Yes, the very same stuff. Boiled Shellac beetles. It makes for nice shiny (albeit fragile) wood surfaces. If you've worked with the stuff you'll know that it makes a hard surface, a little bit like the glue in peanut brittle sweats. This is what used to be used on tubbies before contact glue was invented.

 

Shellac is French Polish.

 

 

[Johan Bornman]

I have ridden tubulars for many years and have yet to experience the "black stuff" of which you speak.

 

If you ride carbon rims or anodised aluminium rims you won't see black stuff on the rims. It was quite evident on older rims that were made from polished, but not anodised, aluminium. The fact that newer rims don't oxidise like that doesn't mean there is no squirm. See if you can find an old tubby rim and look for the telltale black oxide.

 

 

[Johan Bornman]

It seems that other technical guys also know what JB is talking about:

 

From velonews' tech Q&A:

"I do use Tufo tape' date=' but I wouldn?t use it on wheels that must be set up to be as fast as possible. The reason is that test results that I have seen indicate that the rolling resistance is higher with the Tufo tape than with rim cement. This is presumably due to energy loss through hysteresis, caused by the tape squirming around." 

 

http://www.velonews.com/article/73145/technical-q%26amp%3Ba-with-lennard-zinn--tubular-tape

 

The comment was specifically directed at tufo tape vs. glue, but it seems logical that hysteresis behaviour will depend on the stiffness of the glue. A conclusion would be:

 

Stiffer the glue=less hysteresis and=lower rolling resistance.

 

This does not help resolve where RR of clinchers vs tubbies fit in, but leans support to the squirming of tubbies argument.

 

[/quote']

 

Christie, your deductions are spot-on. I have this oldish graph of bicycle tyre rolling resistances. It's original job was to plot the effects of pressure and tyre size, but there are two tubular tyres in the batch and it illustrates the relationship between RR in tubbies and clinchers nicely. It's a jpg file with text in and thus best viewed at its original 100% size. If it's unclear here, anyone can e-mail me and I'll send them the original graph.

 

Interesting to note from this graph is that wider tyres have less rolling resisitance than equivalent narrow ones and that over a certain point, any increase in pressure contributes very little to reduced rolling resistance. The graph flattens out quite markedly.

 

S is Specialised, M is Michelin and Avocet is an American brand that's sadly going down the tubes. It was a very special tyre made by people who understood the business and refused to conform to some of the rubbish perpetuated by the rest of the industry. I'll do a separate post about the bike tyre industry shenannigans in due course.

 

Note the curios American way of expressing pressure (in crooked metric terms nogal).