Is lighter inner tube gives better performance?

[novetan]

I read an article that said latex tube roll 10% faster than common butyl tubes cause its lighter. Its that true and is that really that significant? Does it easily punctured?

If its true, any good brand?

 

[alienator]

 I read an article that said latex tube roll 10% faster than common butyl tubes cause its lighter. Its that true and is that really that significant? Does it easily punctured? If its true, any good brand?

It's predominantly because a latex inner tube is much thinner than a butyl tube. As such, there is less energy lost deforming the tube (and thus heating the tube) as the tire passes through the contact patch. It's that energy loss, aka "hysteresis", that increases rolling resistance. The answer is that yes, latex tubes have lower rolling resistance. Note however that lower rolling resistance doesn't make the picture complete. You have to also consider the downsides. Latex tubes leak air a lot more quickly than butyl tubes, so it's not uncommon for latex tubes need inflating every day. Also, latex tubes are more susceptible to heat damage and failure. It's for that reason that it's strongly recommended to not use latex inner tubes in CF clinchers on mountain descents. For that matter, improper braking on alloy rims can also result in latex tubes failing on descents as a result of heat failure. All of the above can also apply to lighter weight butyl tubes but to a less extent. Note that a lot of people claim that latex tubes are more puncture resistant; however, I'm not aware of any conclusive data on that point.

 

[daveryanwyoming]

Yes, latex tubes decrease rolling resistance. I'd have to look at the data to see if it works out around 10% or not, but it is substantial and measurable with a commercial power meter. I don't believe it's the weight of the latex vs. butyl as much as the flexibility and suppleness of the latex reducing hysteresis losses when it naturally bends and flexes at the ever changing contact patch with the road.

The down sides to latex vs. butyl are that latex leaks air ever so slightly so tires will lose 5 to 10 psi or more overnight so you want to pump up latex tires before every ride. Latex tubes are also very prone to getting pinched under the tire beads during installation so you want to be extra careful installing them to make sure they don't burst as you initially inflate them. For that reason I don't carry latex spare tubes as it's more likely to do a slightly sloppy install while standing at the roadside with a flat so my spares are butyl even when I'm riding latex. Latex tubes also have an insidious tendency to creep into any possible opening in the rim strip which can result in a blowout while riding. So if you use latex tubes make sure your spoke holes are completely covered with rim strip in good condition.

All that makes latex tubes sound like a huge hassle, but they're really not. You have to pay a bit closer attention while mounting your tires to make absolutely sure you haven't pinched any of the very thin latex under a tire bead and you have to keep your equipment in good condition which includes good rimstrip and pumping your tires regularly but they do roll very fast. FWIW, I only race on latex and ride day to day on butyl tubes.

I like Vredstein, Vittoria, and Michelin latex tubes but there are probably others out there.

-Dave

[edit] looks like Alienator got to the line first....so yeah, what he said ^^^^

 

[danfoz]

I'm a big fan of latex innies and use them exclusively these days. My LBS sells Vittoria. They are pricey - $20 vs $5 and as mentioned bleed air quicker than butyl. My experience so far is fewer flats but there is nothing scientific in that claim. I could just be in a low flat cycle. Supposedly being more supple they can deform around the intruding object and not pierce as easily. Mainly I like the way they feel, but that would be hard to put into any measurable terms.

It also occured to me if one were allergic to latex changing a tire could be a problem.