Why is it that road bike tires sidewalls crack and dry out so soon? After only 1.25 years, cracks are noticed right at the seam where the tread ends and the sidewall begins. I have Continental Ultra Race kevlar type tires. I read somewhere they aren't a big deal as long as no bulging or out of roundness is seen. But I wonder if certain brands of tires are better then others. I remember long time ago I had tan sidewall type "gumwalls" and they didn't last long before crumbling away. I wonder if the black chili compounds are better or maybe Bontragers? Maybe you guys wear them out so fast, you don't notice.

I have the same problem with some 26" tyres, also Continental.

Thanks for the reply. I also have some Bontrager Hank 26x2.2" slicks dual compound which I think is a huge version of the some of the dual compound road slicks they sell. 4+ years old and no cracks at all! These have super thin sidewalls. I may be switching brands.

I've used a wide variety of tires and the Ultra Race is one that I won't buy again. Mine wore out faster and gave a worse ride than comparably priced tires.

I just can't imagine a tire still having any rubber left after 1.25 years. If I get 2500 miles out of one I'm thrilled, which means a couple of months at best. Maybe the problem is that when the tire companies select the materials to use they only consider the cyclists who will ride, rather than the ones who leave their bikes all alone for days at a time. Now, the tires on my car...

left in the sun?
near a heating vent?
near an ionic air cleaner?
running the pressure a bit low?

Nope. Max pressure all the time. I ride multiple bikes so it would be nice to have tires where the sidewalls don't dry out. It's the sidewall rubber chemistry. It sucks!!!

You shouldn't be running at max pressure! 110 or so is fine if you weight ~180 less if you're skinny.

why are you on the sidewalk ???

Actually I ride in the gutter. I only ride on the best pavement. Why go slower with less psi. Not!

Max pressure is not required to go fast. Some reading material from the BF Men's Room (library): https://www.bikeforums.net/archive/in...p/t-27368.html

I had the same thing happen last summer with some GP4000's.

Made me nervous enough to trade them out.

Yeah, I was just reading that some manufacture's tires have a wax or silicon additive that actually preserves the rubber. That explains why my bontragers sidewalls are shiny all the time and not cracked.