Originally Posted by
SquidPuppet
It is my understanding that many rubber products contain additives to prevent ozone cracking. I assume then, that some bicycle tire manufacturers have developed recipes that include such additives, and some have not.
There are additives but they can only slow down the problem. Another issue is ozone concentration. How and where it can form is dependent on many different factors. Being near electrical motors almost guarantees high ozone levels but there are lots of other opportunities for ozone formation.
Ozone can form photochemically from a variety of volatile organic compounds. Unburned hydrocarbons from fuels are one source. Formaldehyde outgassing from wood products like the walls of a "shed" could be another source. I work in a laboratory building where rubber products don't last long due to the 10,000 possible chemicals that could form ozone.
I, too, have little problem with tires cracking but my bikes are stored in a 60 year old cinderblock garage with minimal amounts of wood around and certainly few composite (aka "plywood") sources around for chemicals to outgas. But I can see how storing a bike in a "shed" assuming a relatively new (<25 years) wooden plywood shed could be detrimental to
any rubber product.
I still convinced that this isn't the fault of the tire...I have the same brand on some of my bikes that are nearly 4 years old and they aren't showing any checking...but a storage problem.