# Thinking about Zipp 808 firecrest wheels



## RyanM (Jul 15, 2008)

Thinking of purchasing a set of Zipp 808 firecrest wheels for my TT/Tri bike. Since I will be using the bike for both Time Trials and Triathlons should I do tubular or clincher? I'd prefer tubular but not sure if will run into problems using them for tri.
Thoughts?


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## nightfend (Mar 15, 2009)

The only drawback would be trying to fix a serious flat with only tire sealant. The good news is if the sealant works, it will be a heck of a lot faster than fixing a flat on the clincher.


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## asgelle (Apr 21, 2003)

RyanM said:


> Thinking of purchasing a set of Zipp 808 firecrest wheels for my TT/Tri bike. Since I will be using the bike for both Time Trials and Triathlons should I do tubular or clincher? I'd prefer tubular but not sure if will run into problems using them for tri.
> Thoughts?


In general, good clinchers will have lower rolling resistance than good tubulars and so will be faster. http://biketechreview.com/tires/rolling-resistance/475-roller-data


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## Creakyknees (Sep 21, 2003)

asgelle said:


> In general, good clinchers will have lower rolling resistance than good tubulars and so will be faster. http://biketechreview.com/tires/rolling-resistance/475-roller-data


really? then why does the article you link to, show tubies as the top 6 fastest tires?


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## nightfend (Mar 15, 2009)

Not really. Look at the test data. Tubulars rank near the top. The only way clinchers come close is when you use latex tubes, which are fairly difficult to find. Especially now that Michelin is ceasing latex tube production after 2010.

Look at the chart again, and you'll see that a clincher tire with a butyl tube, which is what most of us use for our training wheels does not rate as well on the tests.


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## spade2you (May 12, 2009)

I'm a big fan of the tubulars. Something feels very special about riding them.


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## Hank Stamper (Sep 9, 2009)

Those roller tests are great but the OP probably cares more about speed on roads which when you consider imperfections of roads compared to rollers and the ability to run low pressure on tubes may or may not have any relation to roller tests.


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## asgelle (Apr 21, 2003)

Creakyknees said:


> really? then why does the article you link to, show tubies as the top 6 fastest tires?


Did you read how he glued them? 2 tubes of glue per wheel. How many people will be willing to do that?


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## asgelle (Apr 21, 2003)

Hank Stamper said:


> Those roller tests are great but the OP probably cares more about speed on roads which when you consider imperfections of roads compared to rollers and the ability to run low pressure on tubes may or may not have any relation to roller tests.


From a purely theoretical point of view, that should not be true. The same deformation mechanisms that control rolling resistance on a smooth roller will be acting on a rough surface like a road. While the particular values might be different between a smooth and rough surface, the relative performance between tires will not change. What field testing will tell you that you can't get from roller data (rough or smooth) is optimal pressure for a given tire, but that will depend on the particular rider and road.

But that's not nearly as important as the actual data. 
http://forum.slowtwitch.com/cgi-bin...helin;guest=122345190&t=search_engine#2906987
http://forum.slowtwitch.com/cgi-bin...tance ;guest=38644440&t=search_engine#1909561


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## estone2 (Sep 25, 2005)

asgelle said:


> Did you read how he glued them? 2 tubes of glue per wheel. How many people will be willing to do that?


2 coats, not 2 tubes. I put on 3 layers. One on the rim, let it age 12 hours, one on the tire, let it age 6 hours, third on the tire, slop them together. From what I've heard, that's pretty much the most traditional way to glue tires, and it definitely results in tires that are even more b!tchy to pull off.

I've also seen info that using too much tube per wheel increases CRR (and he makes a comment as to this extent - "The use of less glue seemed in line with improving the Crr of tubulars by reducing the thickness of the "compliant glue layer.")

In other words, your point's not 100% valid. However, you are correct in that a sloppy gluing job won't do as well - too little or too much glue results in higher CRR.


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## asgelle (Apr 21, 2003)

estone2 said:


> 2 coats, not 2 tubes.


5 coats actually equaling 2 tubes

"The test in 2007 was on a Vittoria Crono mounted on a Sub 9 disc using 3 coats of Mastik 1 glue on the rim and 2 coats on the tire (~ 2 tubes of glue per wheel)."

"Definitions - Properly glued => Mastik 1 - 3 coats on Rim, 2 coats on Tire Lightly Glued => Continental - 2 coats on Rim, no glue on tire."
http://www.biketechreview.com/tires_old/images/AFM_tire_testing_rev9.pdf


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## Cableguy (Jun 6, 2010)

> The only way clinchers come close is when you use latex tubes, which are fairly difficult to find.


If you consider searching "Latex Tube Cycling" on google difficult, then yes... they're *very* difficult to find 

And if by "come close" you mean "virtually the same," I agree! The top end ones are all basically small fractions of a watt apart.


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## Ghost234 (Jun 1, 2010)

Honestly I would go for Tubulars for a TT/Tri bike. It will be a little easier for sprinting out of the corners/start/finish and going up hills. Not to mention that if you get a flat on a TT your pretty much screwed. When doing a Tri your not likely going to be carrying around Co2 and all that so the ability to ride to the nearest stop is beneficial. 

Rolling resistance wise, the clinchers might be slightly superior simply due to the momentum of the heavier rim. But you won't really see that benefit unless your going downhill. 


Also: Latex tubes = teh sex. It shocks me that Michellin will be stopping production soon. I will have to take a drive to the 2 stores that I know sells them and buy out the rest of the stock. Outside of pumping the tires up every time I ride (I do that with butyl regardless), latex feels more comfortable and from my experience it seems to be more flat resistant when they are installed properly (they burst quite easily during installation).


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## asgelle (Apr 21, 2003)

Ghost234 said:


> Rolling resistance wise, the clinchers might be slightly superior simply due to the momentum of the heavier rim. But you won't really see that benefit unless your going downhill.


Momentum has nothing to do with rolling resistance. Mass does, but the difference between a clincher and tubular wheel is small enough that it is usually not a deciding factor.


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## RyanM (Jul 15, 2008)

appreciate all the comments. Im leaning toward tubular but we will see


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## mimason (Oct 7, 2006)

I have 808 tubbies for my tt bike. Since they are race day only wheels I'd go tubular. If you flat you are through anyway and they feel real nice.


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