it's easy buy some Latex tube's use clincher and go faster! and it will cost less in the end.

http://www.biketechreview.com/...ire_testing_rev6.pdf

Dan...

When can start the debate again about biketechreview.com and how they did not follow the manufacturer's recommendation for tire pressure for their tire test...

It is ironic that Zipp talks about tire pressure in the podcast as to why they believe it is critical to inflate your tire to the right pressure to get the best Crr but sometimes that falls on deaf...

I do both

For a superlight road racing wheelset (courses with heavy climbing), my best choice was the new 202 set, 32mm tub/700c

Using tangent tires as well

First race on the wheels is San Dimas SR next weekend

For crits, rolling courses I use 404 clinchers, they are solid and fast, but 700g heavier than my 202s

 

A strong case? Do ya really think so? Is that based on this quote?

"...you know, there's a lot of stuff that's been kicked around the last few years on the internet...testing, you know are clinchers better, are tubulars better? ...And I think that we can, umm..we can say comfortably with all the data available that from a rolling resistance perspective they're probably about equivalent in most cases."

Hmmm...lots of "qualifiers" in that statement (that's engineering talk for "weasel words" ;-)

OK...so the trade-off is just making sure you use latex tubes (which, IMHO, are really not any worse to use than butyl once you decide to take just a modicum of care intalling them) in your clinchers vs. getting your tubular glued on straight, with the right glue, with the right gluing technique. On top of that, the best clinchers with butyl STILL have lower rolling resistance than the mid-pack or worse tubulars which have butyl tubes in them as well.

I guess I'm just not seeing the "strong case" for the typical consumer to use tubulars over clinchers...

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http://bikeblather.blogspot.com/

That's right, they do talk about using the proper pressure. The point was to have a consistent contact patch size across different loadings. Did you also listen to the explanation about why running too high of pressure (basically anything above ~120psi) is counterproductive?

Think about that a little and you'll realize why AFM's testing reported over on BTR uses a "standard" 120psi across the board. It's the only way to do an "apples to apples" comparison across different tires to see how they'll perform in the same situations.

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http://bikeblather.blogspot.com/

Tom correctly points out the contact patch area spec which is what the pressure spec is really targeting. Let's look at the Zipp spec for tubulars and clinchers. For the weight range of 175 - 200 lbs the pressure spec is 126 and 122 psig respectively for riding in an aero time trial position. This in reality defines an acceptible contact patch range of 1.39 to 1.59 in**2 for tubulars and 1.43 to 1.64 in**2 for clinchers. My weight ranges in the low to mid 180's - doing the math for that weight range and a tire pressure of 120 psig shows that I'm within the Zipp specification for both the Zipp clinchers and tubulars. The contact areas calculated here are of course not correct in the real world as the weight of the bike (which varies from rider to rider) must be added to yield the actual total weight. Additionally the contact patch areas are the total for the 2 tires proportional to the weight distribution from front to rear tire - in my case in the aero position ~ 53% of the total weight is supported by the rear wheel/tire. Hopefully this sheds some light on the BTR Crr tire pressure discussion/debate.

Al (AFM)

Just got delivery on a 6-pack of Michelin Aercomp latex tubes to start using w/a set of Veloflex Pave' clinchers (on Zipp 808's) - decent 'bulk' price on cbike.com compared to other sites. I'm curious to see if the feel is noticeably different (better) than my standard butyl tube / Michelin tire combo. I wrestled with the notion of converting to sew-up's for my race wheels this season but I couldn't get over the hump and will try the latex tubes now...

I just ordered the same tubes. I have no experience with laxex (except the obvious!!). In terms of installation, do you need to use talc power like regular tubes? The reason I ask, is because I've seen others giving reference to people not installing latex tubes correctly.

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I was assuming the extra care in installing latex tubes was about making double-sure the tube doesn't get pinched between the bead and sidewall.. These chic, sea-foam green tubes seem to be pre-powdered -- they're not sticky at all.

Gotcha thanks. Any idea on the durability of them once they are installed correctly. I know they lose air quicker, which isn't a big deal. I wouldn't think they would flat easier as this seems to be more dependent on tire (I would think).

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I'm bracing myself for these to be less durable than the current tire / butyl inner tubes I've been using - though my opinion is based on running the lighther Veloflex tires moreso than the latex tubes themselves. Anyhoo, these are for my race wheels, not necessarily everyday use. Depending on how they feel, I may be a perm. convert (?)

Here's the write-up from CompetitiveCyclist.com:

Why go latex? The main benefit is clear-cut: Weight savings. You'll save about an ounce per wheel -- 10-20g depending on which tube you compare it to. That might not sound like much, but when you're talking about weight at the outside of your wheel, every little bit really does count. We've also seen tests that indicate latex tubes have lower rolling resistance than butyl rubber. And -- not sure if you should file this in the urban myth department or not -- some folks suggest that latex is more pliable than butyl, giving it superior resistance to pinch-flats.

The only downside to latex is that tube walls are considerable more permeable than butyl rubber. This means that you'll need to air up your tires every single day. No, you cannot skip a day. And if you take a week off riding, your tires will appear flat.

If airing up is the only issue, then I'm sold. I wonder how strong the area around the valve is in terms of durability. Any regular tube that has failed on me (other than punctures) has been a tear around the valve.

This will be used as a race wheel for me also.

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I've installed the same tube over and over again for tire testing with no problems. What I do is to blow some air into the tube to give it shape, install the tire & tube on the wheel, and then inflate slightly to ~ 5 psig. I then move around the tire on both sides pushing in the side wall to make sure that the tube isn't pinched. Verifying that I'll inflate to 120 psig. Takes a few minutes but seems to work well. Make sure that your rim tape is in good shape - the latex will take any opportunity available to "flow" into the slightest gap and pop !!