Latex tubes required?
My wheels are all set with Vittorias, FC 404s, etc...but i need valve cores to extend the latex tubes (have, cant find). Should I make this happen oir just not sweat it????
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My wheels are all set with Vittorias, FC 404s, etc...but i need valve cores to extend the latex tubes (have, cant find). Should I make this happen oir just not sweat it????
Comments
If you want you can find them here. I still have my latex tubes sitting on the table in the garage from last years IM... i.e, Didn't sweat it.
Good Luck this weekend P...
D
You certainly do NOT need them, so don't sweat it if you can't find them. But definitely use them if you can find the extenders without too much stress.
I would remove the valve core put on extender and then teflon tape the seals and re-install the valve core on the extender. That way you don't have to worry about the valve rattling shut and you have access to the valve. If you are takinga sealant like a vittoria pitstop with you then I would also bring the valve core tool with you since the pitstop doesn't go into tire very well through the valve core.
Here are the zipps: http://www.zipp.com/accessories/detail.php?ID=16716
I use the less expensive maxxis and they work just as well: http://www.amazon.com/Maxxis-MVS-80mm-Presta-Valves/dp/B004JKCHSA
Coach P,
I'm with Matt find the valve cores. I'm sure you could get some in Kona as mentioned. You are at the pointy end of the stick and this stuff matters. You took the time to do the bike tweeks, shorter cranks and roto cranks find the valve cores.
Just in case you aren't convienced yet. Below is from the biketech review. You can see 2.3 watts per tire. You just did that 20' test recently how much would you give for 5 more watts?
Vittoria Open Corsa EVO CX (23)/Butyl Tube
24
0.00307
0.00040
15.1
2
1
Used Tire ~ 40 miles - Specialized Turbo Butyl Tube
Vittoria Open Corsa EVO CX (23)/Mich Latex Tube (22/23)
24
0.00261
0.00001
12.8
2
1
Same Tire
Gordon
For the non-techies who wonder what all this is about: latex tubes = decreased rolling resistence. Decreased rolling resistence = higher speed @ same power output.
So, Coach P will NOT increase his wattage by using them; he'll work at his expected NP, and hopefully go a bit faster than he would with butyl tubes.
Some people feel latex tubes are more fragile and either more easily flat or leak air. And, as Steve S. notes above, there are also issues with getting valves extenders to work properly/well. This is not advice for Coach P, but for those reasons, I don't use them. Maybe I should start? (But not @ this race!)
Oops - now that I woke up, I should add... latex = lower weight = less angular momentum (is that the proper term?) = less effort required to keep wheel rotating = higher speed at same power.
And I remembered another reason I don't ride latex tubes - they are not made anymore for 650c tires!
@Al - Thanks for the clarification. I should not get so liberal with my comments. As noted its all about decrease rolling resistence which saves those extra watts. Definitely a good point if you are not comfortable with the extenders working properly this might be a game changer.
Gordon
The three things I would keep in mind when running latex are:
- Be careful installing them as it is easy to pinch them, but this is really the same with any tube and if you probably install them this is a non issue. In other words don't use a tire lever to put the tire on. The 404 CC as super easy to put tires on so this will not be an issue.
- Make sure to pump your tires up race morning (but again you should already be doing this anyway)
- C02 and latex don't get along for long periods of time. You can use it and it will work but it will leak out faster than air would. Most people do not use latex spares.
I put talcum powder on the inside walls of the tires as well when using latex tubes to allow them to move around a bit and not get stuck to the tire. If you want added assurance put in 20-30ml cafelatex for flat prevention. I use this stuff on my tubulars with latex tubes as the cafelatex will not eat the latex tube like Stan's.
Can you clarify your original question. I read it to mean you waited until the last minute and didn't get the proper valve extenders in time and now you are scrambling to find them in time for your trip, and aren't sure it's worth the headache at this point. And with 404's, you can simply buy butyl tubes at your LBS with 80mm stems and you're good to go.
JW's gear head tube summary:
1) Use the Latex if possible, you are certainly fast enough for it to matter.
2) Buy 3 of them, because there's a good chance you make one explode on initial installation (be careful)
3) Do NOT use CO2 with your latex tubes, only a regular pump, and definitely on race morning.
4) you will not need tire levers with Vittoria Open Corsa Evo CX tires, just use your hands and no need to take tire levers for the race.
5) Take butyl spares with 80mm stems and forget extenders for these (don't forget your CO2).
6) Buy the 30mm valve extenders that you can remove the cores and put them at the top like these: http://tinyurl.com/9ofmbx4 (can probably get them at your LBS or at the Expo in Kona). You do not need to wrap the threads on these extenders with plumbers tape, they already have a rubber seal.
7) If you cannot find these extenders, buy the crappy Zipp ones and use the Latex tubes anyways, but don't forget to wrap the threads with plumbers tape.
8) Crush that bike course, but set up a great run!
And P, get the latex. Valve extenders are ubiquitous. Keep butyl for spares. Might as well start on the fastest rig you can.
I believe Michelin said that their latex tubes could be patched with a standard patch kit. If I flat on latex though I can usually repair with sealant unless it's a big gash.
Then read this: Valve extender how to [good slowtwitch article that should explain/demystify everything].
Glad to hear you mention the first part, when I swapped from latex tubulars to clinchers with latex tubes I found this specific aspect disconcerting at first since I had not heard much mention of it. However, when removing latex tubes, I found that they had become pretty well stuck to the inside of the tire. Wasn't sure if that was expected or a bad sign.
As for adding tire sealant, I think there was a like a 3 page article on using tire sealents in LAVA a month or so back and I couldn't believe they didn't mention what is to me, the single biggest caveat with using sealents: the supposed increase in Crr. Honestly, I have no objective data to back it up with, but after having heard it for years on ST I have always assumed that adding sealent to latex tubes would sort of defeat the purpose, if I was going to increase my Crr to add puncture resistence, I could have just stayed on butyls. But again, hearsay.