Tyre blow-out.

[Laterider21958]

Have Specialized Infinity tyres on our bikes - 70-100 psi. The tyres have a lot of tread and aren't worn, even though they are 3 years old, but one basically blew out while the bike was stationary. It hadn't been ridden for a week and the tyres were inflated at 80 psi. The tube blew a hole right through the kevlar (not sure of the spelling) lined tyres, resulting in a 5 cm diagonal rip in the tyre with fibre shreds poking out of the tear. Is this the usual thing to happen? (There were no foreign objects embedded in the tyre or the tube and the temperature on the day was around 30 deg C.)

Just curious as we have 3 more of these tyres yet to explode!

[OakLeaf]

Are the tires three years old from date of manufacture, or do you mean they've been on the bike for three years?

Now, this is odd... I know the Michelin Lithion tires I used to run were date coded the same as motor vehicle tires, but I'm danged if I can find a date code on my Conti GP4000s or DH's Bontrager Race Lites. Anyone know what's up with that?

Anyway, NO, it's not "usual." Three years is getting up there, but it really isn't too long in the life of a tire. But, if the tires had already been sitting around for a year or two before you bought them, they definitely could be starting to harden and/or dry rot. Check them very carefully for brittleness. That'll be easy to do on the one that blew. Have you noticed that the tread isn't as grippy as it used to be?

[Laterider21958]

Checked for a date on the tyres and found (20051049), so I guess they were manufactured in 2005. (Didn't know that tyres are supposed to be dated. Will keep that in mind when purchasing replacements.) The ruptured tyre appeared very flexible, with no visible cracks and it seemed to feel the same as it always had on the road. Now hoping that it was a faulty tyre from the start, and that the remaining 3 don't do the same thing. One good thing about the blow-out - at least it happened while it was parked at home and not during a ride.