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Looking for opinions. I have two boxed conti super sonic tires. They are discontinued 650x20 clincher for my 650 hed 3. Who knows how old they are 10 years plus? Wondering if the rubber becomes less supple.
Normally I know this is the fastest option, but because of age (they seem fine) I wondered if the Vittoria open corsa evo cx would be a better choice. I know they're not too aero.
Happen to be any other options in 650x20?
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Rider17: Nov 26, 14 10:09
Are they the gray tread ones or older?
Yes, they have the gray tread.
Rubber compounds cross-link over time, which means longer molecule chains and less flexibility. How much varies hugely with the conditions in which they were stored - hot, cold, humid, dry, etc. In hot, dry conditions, you could see significant hardening in 10 years to the point that you'd start to see dry rot. If they look and feel O.K., maybe stored in a basement, they might still be safe to ride on but won't be the same as new tires. Some cross-linking is beneficial in that it makes them more puncture-resistant, but any decrease in flexibility means they will have higher drag because of higher hysteresis, and they'll be a bit less grippy.
Brian
Brian
Gonna buy a fast car, put on my lead boots, take a long, long drive
I may end up spending all my money, but I'll still be alive
That tire is OK but the Vittoria Corsa CX 650X21 is a better tire for that wheel.
Before the tire is mounted, if you feel the tread between your fingers, it feels really flexible and thin. To me that's an indication of a fast tire. That tire would have to be just about brand new for me to trust it though.
The Vittoria is a little tougher tire and I have much more confidence using it.
jaretj
The fastest rolling tire I have is >10 years old, and when I run it as a control tire the Crr hasn't changed during that time. So, if the tires are stored at room temp my thoughts are no.
Only way to know for sure though is to test it. I used a Vittoria Ultraspeed 650C x 20 on my funny bike--it was pretty much the perfect tire for H3.