General Discussion Triathlon Talk » Latex tubes.....school me Rss Feed  
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2014-03-19 12:30 PM
in reply to: dmiller5

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Subject: RE: Latex tubes.....school me

Originally posted by dmiller5

Originally posted by Aarondb4

 

Can I get some more opinions on the "feel and handling" aspect? It surprises me that the tube could really make much difference in the feel and handling, would think the tire does most of that. Is it really enough to feel a difference?

If the latex tube is more supple does that mean you have to run a higher pressure in the tire? Would seem if the tube is more supple, the same pressure would give you more slack in the tire and this increase rolling resistance. So do you have to go 120psi in a latex where you would normally go 110psi in a butyl?

Being more supple does not mean you need more pressure. A tire can be more supple. For instance your conti 4000s has a higher thread count than your gatorskin, making it more supple; you would use the same pressure. Optimal pressure is governed by load and by weather conditions.

The feel and handling is better because of how the tire will conform to the road. a more supple tire (and tube) will conform with less pressure applied, giving you better "grip." Tubular tires tend to have a better road feel because they do not have tubes inside them like a clincher does. A latex tube gets you closer to a tubular "feel."

"Tubeless" has no tube inside. Tubular has a tube and the rubber is sewn all the way around it. You buy the whole thing together. I believe the tubular has a bit more tire available to flex because of how they attach vs how clinchers do. Part of the difference before was also in the tubulars having latex tubes and previously being having better tire material/design, however clinchers have much improved since then. Not sure if there is much difference there anymore in handling. No first-hand experience with tubulars for that.

And the right on with the more supple being more conforming. There isn't extra "slack" in the tires or the pressure would not have been as high in the first place. The material both flexes more easily in the first place and springs back to shape more easily returning that energy better.



2014-03-19 12:48 PM
in reply to: dmiller5

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Subject: RE: Latex tubes.....school me
Originally posted by dmiller5

Originally posted by mike761
Originally posted by Aarondb4

 

Can I get some more opinions on the "feel and handling" aspect? It surprises me that the tube could really make much difference in the feel and handling, would think the tire does most of that. Is it really enough to feel a difference?

If the latex tube is more supple does that mean you have to run a higher pressure in the tire? Would seem if the tube is more supple, the same pressure would give you more slack in the tire and this increase rolling resistance. So do you have to go 120psi in a latex where you would normally go 110psi in a butyl?

Its snake oil!!! It does just about anything, that's all you need to know. The test that are out there for the public to look at have several variables that are not tested, and therefore you cannot draw conclusions from. Although most do as you have seen.

Not sure what you are on about, could you provide some evidence to back up whatever you are trying to say? There have been multiple published tests by third party sources that have all confirmed something close to a 3 watt/wheel difference when using a latex tube.




In all the published tests I have seen including the links in this thread variable were not examined in those test.

For instance; the obvious is the tire pressure was not varied in each test, they were all conducted at 120psi, which is above what most of us if not all of us should be riding at. The one part of the test that that varies the tire pressure started at 120 and went up to something like 180psi show the rolling resistance going down the whole time. In reality rolling resistance will have a sweet spot for your system too little pressure your RR goes down and too high a pressure your RR will go down. The sweet spot for Butyl tires may be at 90psi were as the sweet spot for latex may be at 120psi.

There are other variables in this as well that need to be isolated and tested.

Just because its on the internet doesn't make it true.
2014-03-19 1:02 PM
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Subject: RE: Latex tubes.....school me

Originally posted by mike761
Originally posted by dmiller5

Originally posted by mike761
Originally posted by Aarondb4

 

Can I get some more opinions on the "feel and handling" aspect? It surprises me that the tube could really make much difference in the feel and handling, would think the tire does most of that. Is it really enough to feel a difference?

If the latex tube is more supple does that mean you have to run a higher pressure in the tire? Would seem if the tube is more supple, the same pressure would give you more slack in the tire and this increase rolling resistance. So do you have to go 120psi in a latex where you would normally go 110psi in a butyl?

Its snake oil!!! It does just about anything, that's all you need to know. The test that are out there for the public to look at have several variables that are not tested, and therefore you cannot draw conclusions from. Although most do as you have seen.

Not sure what you are on about, could you provide some evidence to back up whatever you are trying to say? There have been multiple published tests by third party sources that have all confirmed something close to a 3 watt/wheel difference when using a latex tube.

In all the published tests I have seen including the links in this thread variable were not examined in those test. For instance; the obvious is the tire pressure was not varied in each test, they were all conducted at 120psi, which is above what most of us if not all of us should be riding at. The one part of the test that that varies the tire pressure started at 120 and went up to something like 180psi show the rolling resistance going down the whole time. In reality rolling resistance will have a sweet spot for your system too little pressure your RR goes down and too high a pressure your RR will go down. The sweet spot for Butyl tires may be at 90psi were as the sweet spot for latex may be at 120psi. There are other variables in this as well that need to be isolated and tested. Just because its on the internet doesn't make it true.

Take the test that was linked to on this thread, a well regarded test btw. 120 psi with 100lb load on the wheel. That is pretty consistent with everything I know about tire inflation/weight. I don't see the problem here.

As for the decrease in RR with the increase in pressure, that is 100% consistent with the laws of physics. On a PERFECTLY SMOOTH surface, ie what they tested on, higher pressure reduces rolling resistance because it reduces the contact area between the wheel (tire) and the ground. Now, you are right, in reality that would not work well on a road that is not perfectly smooth for several reasons that I'm going to gloss over right now because I don't think anyone is arguing this point.  On a rougher road, there IS a sweet spot of pressure that yields a better rolling resistance. However, no matter your pressure, a better tire is going to yield a lower rolling resistance than a worse tire (at the same pressure). These are all facts that I don't think people will really dispute.

Now what is the takeaway for us with the information we just revealed?

A more pliable tire has better rolling resistance on a smooth surface.
A more pliable tube has better rolling resistance on a smooth surface.
A highly inflated tire (less pliable) has WORSE rolling resistance on a rough surface.

So likely, the difference between a more pliable tire and a less pliable tire would be greater on a rougher road. This would lead us to believe that the 3 watt difference could potentially be an UNDER estimate of the actual power savings experienced between a butyl and latex tube on a real road.



Edited by dmiller5 2014-03-19 1:11 PM
2014-03-19 2:00 PM
in reply to: wannabefaster

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Subject: RE: Latex tubes.....school me
Originally posted by wannabefaster
For someone like me who is closer to 200 watts (or less) for a HIM, 6 watts is an even bigger percentage of my power.


It's this kind of math that really sells bike equipment. 6 watts isn't a constant.

My opinion, If you've got extra time and money to spare, then by all means try it. I can't tell you if they were a few % points faster or not. Felt exactly the same as far as riding goes and were a pain in the butt to install; never went pop thankfully but inflating them is stressful. To me personally the time spent installing and removing after a race coupled with the cost, not going bother until there are prizes on the line.
2014-03-19 2:02 PM
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Subject: RE: Latex tubes.....school me


As long as you stay close minded you will believe these to be facts. There are other test out there that directly disput some things you say here. You also jump to even more conclusion's based on no facts. Everything you say here suggests that if we lower the tire pressure it will be more pliable(your words) and there for have better rolling resistance on smooth surface such as steel rollers which is not what we ride on.

I'm saying that these test have several variables that were not tested. There is also comments from an independent lab that's done far more testing that says that light weight butyl tubes are just as good as latex for rolling resistance. Of coarse a lot of this info does not come out because it is proprietary and can not be released.

I'm sure you are saying that I'm just crazy, however I was doing composite wheel design and manufacture for Mavic back in 2003-2004. So yes I do know what I'm talking about. I am always reluctant to post on this kind of thread because I know most will ignore me and accept what they have heard form others 1000 times regardless of the quality of the data.

Do you really pump your tire to 120psi? you should re -think that if you do.

Edited by mike761 2014-03-19 2:03 PM
2014-03-19 2:09 PM
in reply to: mike761

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Subject: RE: Latex tubes.....school me

Originally posted by mike761 As long as you stay close minded you will believe these to be facts. There are other test out there that directly disput some things you say here. You also jump to even more conclusion's based on no facts. Everything you say here suggests that if we lower the tire pressure it will be more pliable(your words) and there for have better rolling resistance on smooth surface such as steel rollers which is not what we ride on. I'm saying that these test have several variables that were not tested. There is also comments from an independent lab that's done far more testing that says that light weight butyl tubes are just as good as latex for rolling resistance. Of coarse a lot of this info does not come out because it is proprietary and can not be released. I'm sure you are saying that I'm just crazy, however I was doing composite wheel design and manufacture for Mavic back in 2003-2004. So yes I do know what I'm talking about. I am always reluctant to post on this kind of thread because I know most will ignore me and accept what they have heard form others 1000 times regardless of the quality of the data. Do you really pump your tire to 120psi? you should re -think that if you do.

Do you have any test results or data to read?  Like I said, this is school for me, I'll read whatever is out there.....but I won't just take comments like yours above without some sources.  (not meant to be mean spirited, just would like to see the studies/data)



2014-03-19 2:14 PM
in reply to: mike761

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Subject: RE: Latex tubes.....school me

Originally posted by mike761 As long as you stay close minded you will believe these to be facts. There are other test out there that directly disput some things you say here. You also jump to even more conclusion's based on no facts. Everything you say here suggests that if we lower the tire pressure it will be more pliable(your words) and there for have better rolling resistance on smooth surface such as steel rollers which is not what we ride on. I'm saying that these test have several variables that were not tested. There is also comments from an independent lab that's done far more testing that says that light weight butyl tubes are just as good as latex for rolling resistance. Of coarse a lot of this info does not come out because it is proprietary and can not be released. I'm sure you are saying that I'm just crazy, however I was doing composite wheel design and manufacture for Mavic back in 2003-2004. So yes I do know what I'm talking about. I am always reluctant to post on this kind of thread because I know most will ignore me and accept what they have heard form others 1000 times regardless of the quality of the data. Do you really pump your tire to 120psi? you should re -think that if you do.

No, I don't weight that much so I inflate to a lower pressure. Light weight butyl is better than normal butyl for RR....for the same reasons latex is better.

The bolded doesn't make any sense. The reason higher pressure is better on rollers is that you need a certain surface area to hold up the weight. Higher pressure means less surface area....pounds per square inch...psi. There is less friction so less energy loss. As I said, on the road, this isn't the limiting factor because the ground isn't so smooth and even. So, we find that there is a sweet spot. low enough to be ride-able, grip the road, bounce around, whatever, and high enough to have the minimal possible surface area. It is a balance.

My point about the 3 watts is that we see on a real road, that overinflation is no a good thing. Part of this is the tire's inability to flex enough on an uneven surface. The latex tubes take less energy to flex, (more pliable) and we could infer that you would lose less energy from a latex tube on a bumpy road because less energy is being used to flex the tube.

You make many fun claims about much better studies and super special information, then insult me because I will ignore you in spite of the data. Why don't you try idk..... providing the data. Seems more productive than yelling about snake oil and making unsubstantiated claims. Then again I'm just a kid so what do I know.

2014-03-19 2:15 PM
in reply to: Left Brain

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Subject: RE: Latex tubes.....school me
Get the latex tubes extra thin to maximize your riding pleasure.
Forget about those fancy ribbed types that are supposed to help your competitors.
2014-03-19 2:28 PM
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Subject: RE: Latex tubes.....school me

Originally posted by mike761
Originally posted by dmiller5

Originally posted by mike761
Originally posted by Aarondb4

 

Can I get some more opinions on the "feel and handling" aspect? It surprises me that the tube could really make much difference in the feel and handling, would think the tire does most of that. Is it really enough to feel a difference?

If the latex tube is more supple does that mean you have to run a higher pressure in the tire? Would seem if the tube is more supple, the same pressure would give you more slack in the tire and this increase rolling resistance. So do you have to go 120psi in a latex where you would normally go 110psi in a butyl?

Its snake oil!!! It does just about anything, that's all you need to know. The test that are out there for the public to look at have several variables that are not tested, and therefore you cannot draw conclusions from. Although most do as you have seen.

Not sure what you are on about, could you provide some evidence to back up whatever you are trying to say? There have been multiple published tests by third party sources that have all confirmed something close to a 3 watt/wheel difference when using a latex tube.

In all the published tests I have seen including the links in this thread variable were not examined in those test. For instance; the obvious is the tire pressure was not varied in each test, they were all conducted at 120psi, which is above what most of us if not all of us should be riding at. The one part of the test that that varies the tire pressure started at 120 and went up to something like 180psi show the rolling resistance going down the whole time. In reality rolling resistance will have a sweet spot for your system too little pressure your RR goes down and too high a pressure your RR will go down. The sweet spot for Butyl tires may be at 90psi were as the sweet spot for latex may be at 120psi. There are other variables in this as well that need to be isolated and tested. Just because its on the internet doesn't make it true.
If the road surface remains the same then a tire with a sweet spot at 90 psi should have a more comfortable ride with lower Crr when latex tubes are used.  No need to change the PSI if the 90 psi provides the optimums for a rider.  The sweet spot may not be the same for each rider as each has their own weight, rims (width), etc.

Here's a chart with a certain tire that shows the measured Crr vs increasing psi on smooth rollers, rough rollers and road.  On the road actually diverged from the rough rollers Crr after a certain PSI.  But others have stated it was not repeated on other testing/tires.

Perhaps read through this ST thread and if you still have questions ask Tom A himself.



Edited by Donto 2014-03-19 2:45 PM
2014-03-19 2:30 PM
in reply to: Donto

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Subject: RE: Latex tubes.....school me

link appears dead to me?

2014-03-19 2:46 PM
in reply to: dmiller5

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Subject: RE: Latex tubes.....school me

Originally posted by dmiller5

link appears dead to me?

Fixed it

 



2014-03-19 2:48 PM
in reply to: Left Brain

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Subject: RE: Latex tubes.....school me

Here is a good primer on tubes, as will as tire pressure.  As noted, the reason latex+tire tends to produce lower rolling resistance than butyl+tire has to do with the elasticity of latex vs. butyl.  The former has greater elasticity and therefore lower hysteresis (enegy loss as it deforms and then returns to its unloaded state).  The exact savings in watts will vary based upon many factors (tire used, tire pressure, road conditions, etc.).  I've seen enough testing to believe there is some benefit (have not tried my own testing).  And, knowing the elastic properties of latex vs. butyl, it at least makes sense that benefit should exist.

2014-03-19 2:51 PM
in reply to: mgalanter

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Subject: RE: Latex tubes.....school me
Originally posted by mgalanter

Get the latex tubes extra thin to maximize your riding pleasure.
Forget about those fancy ribbed types that are supposed to help your competitors.



lolz. thanks for that. we needed some comedic relief in this thread.
2014-03-19 3:25 PM
in reply to: Left Brain

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Subject: RE: Latex tubes.....school me
Latex tubes feel better and roll faster for me over all surfaces. They are better. I don't flat anymore than butyl. You just have to pump them up before every ride. They don't hold air like butyl. Some people who know what they are talking about have already said it on page 1, but just throwing another vote in there.

Or don't use them and don't go faster. Fine with me if I'm the only one using them. I don't get why people think you flat more. I'm not a mechanic and seem to be able to put rim tape on and install a tube fairly easily. I remove the valve core and screw in one to make it longer for the Hed 6. Takes 2 seconds. I really question if the people saying they aren't faster have logged thousands of miles on each butyl and latex holding other things constant. There is a difference. I'll take any watts I can get.
2014-03-19 3:48 PM
in reply to: Aarondb4

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Subject: RE: Latex tubes.....school me
Originally posted by Aarondb4

 

Can I get some more opinions on the "feel and handling" aspect? It surprises me that the tube could really make much difference in the feel and handling, would think the tire does most of that. Is it really enough to feel a difference?

If the latex tube is more supple does that mean you have to run a higher pressure in the tire? Would seem if the tube is more supple, the same pressure would give you more slack in the tire and this increase rolling resistance. So do you have to go 120psi in a latex where you would normally go 110psi in a butyl?




The feel is closer to riding a tubular vs a regular clincher tire/tube combo.

The latex tube helps absorb the imperfections of the road along w/ the correct pressure (less is more).
2014-03-19 3:52 PM
in reply to: chris948

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Subject: RE: Latex tubes.....school me
Originally posted by chris948

Originally posted by wannabefaster
For someone like me who is closer to 200 watts (or less) for a HIM, 6 watts is an even bigger percentage of my power.


It's this kind of math that really sells bike equipment. 6 watts isn't a constant.

My opinion, If you've got extra time and money to spare, then by all means try it. I can't tell you if they were a few % points faster or not. Felt exactly the same as far as riding goes and were a pain in the butt to install; never went pop thankfully but inflating them is stressful. To me personally the time spent installing and removing after a race coupled with the cost, not going bother until there are prizes on the line.


I am one of those ding-dongs that has a completely different set of race wheels. Installing latex tubes when I get new tires is a relatively painless adventure that I "think" improves my riding experience (speed), however slightly. Done once a year the latex tubes may take me an extra 10 minutes. Time well spent. Last year at a race I noticed that I was passing people on the downhills while coasting. I am a 145 pound pipsqueak and I was blowing by folks who outweighed me be 30 pounds or more, without pedaling. That shouldn't be happening. I am convinced that part of why this happened is that I have concentrated on a lot of little things to help me be faster..... maybe a little bit of bro-science but I was convinced.

Training and racing is important to me and I like to optimize, or at least believe that I have optimized my equipment. In all of this I have yet to see anyone present data that latex tubes are worse. There seems to be a few who are arguing that latex isn't better but I have yet to see anything to argue against this commonly held belief about latex tubes reducing CRR, however slightly. ("Trust me, I know a lot about this" isn't enough to convince me)

I am pretty sure that I could not tell the difference if you put latex or butyl tubes in my tires. I know that I am not that sensitive. I do know that I ACTUALLY have latex tubes. I KNOW that it makes me faster even if it is only in my head.


2014-03-19 4:09 PM
in reply to: wannabefaster

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Subject: RE: Latex tubes.....school me

For me it's one of those things I just have to trust the science on. 

2014-03-19 5:13 PM
in reply to: msteiner

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Subject: RE: Latex tubes.....school me
Me too.. I learned a lot reading all this about tubes,, thanks everyone..
2014-03-19 5:26 PM
in reply to: kandk

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Subject: RE: Latex tubes.....school me

One thing I don't see discussed much about latex tubes is that they can stick to your tires and be hard to change if you get a flat IF they have been in your tire for awhile. I have race wheels I don't ride much so I had same tires/tubes for over a year. I flatted in first 2 miles of an IM bike, and had much harder than normal time with the tube. I still have it and it conformed and looks like the inside of my wheel.

I would suggest sprinkling baby powder over the latex tubes in a plastic bag before installing them and if you aren't going to ride those race wheels for awhile like months ie over the winter, take the tubes out over the winter.

 

2014-03-19 7:02 PM
in reply to: KathyG

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Subject: RE: Latex tubes.....school me
Count me as a fan of latex. I can't take the time to re-test what others have already done, but I like the feel of them and believe the testing. I've had flats with them, but no more (or less, unfortunately) than with butyl and none that wouldn't have happened in either case. I've started adding sealant to them which testing has shown does NOT increase the rolling resistance or negate the effects of a good tire and tube. In addition, it slows the air loss. I've been using 'Air Attack' and it's been good so far. I tried Stan's, but it ended up as a big glob of latex inside the tube so I switched. Also, Air Attack doesn't dry out over time.

As to installation, I don't do anything different than I do with butyl. If you are doing it differently, then you are probably lucky you haven't had a blow out with butyl rather than unlucky with the latex. The steps are simple:

Assuming your rim tape is good (if not, remove it and apply a strip of packaging tape, then put your rim tape back on):
1) Wipe some baby powder on the inside of the tire. This is most important with new tires.
2) Install the tube inside the tire. Some find it helpful to put a little air in the tire. Finish installing the tire on the rim.
3) Pump the tire up to ~15 psi.
4) Starting at the valve, use your thumbs to push in the tire bead and physically check and verify the tube is not showing. Check all around the tire on both sides.
5) Pump the tire up the rest of the way.

This method has worked for me for years with no installation issues, both latex and butyl.

Just to clear up a few factual errors in this thread:
1) Sealant does NOT add rolling resistance (according to the people who have tested it). It adds a small amount of weight.
2) Tubular tires (sew-ups) DO contain a tube. Sometimes it's latex-based, sometimes it's butyl.
3) Latex tubes being more or less prone to flats is all conjecture, although the testing performed for SlowTwitch seems to show that sealants work better with latex tubes.
2014-03-20 8:47 AM
in reply to: dmiller5

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Subject: RE: Latex tubes.....school me
Originally posted by dmiller5

link appears dead to me?




It married outside its religion?



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