Originally Posted by Tony_G

TL, DR:
Is it safe and effective to use a tire rubber conditioner? I know Amour All is not safe due to making the tread slippery. But I bought an automotive product called 303 Tire Balm, that claims UV and ozone protection for tires.

Backstory and more info:

I replaced my Continental GP 4000 II tires last week, they had 10,800 miles on them. The tires are 14 months old (on the bike, not the manufacture date), and when the bike is not in use, it is garaged.

I love these tires for their grip, low rolling resistance and long life.

But I didn't replace them because they were worn out. The tires deeply cracked on the shoulder of the tread. Not quite the sidewall, in a heavily leaning curve, the cracks could contact the pavement. The cracks went around 95% of the entire tire, on both sides and both tires.

A web search provided guesses that this is due to ozone or UV damaging the rubber, or both.

I applied 303 Tire Balm (an automotive product) to both new tires, a GP 4000 IIs on the front, and the new GP 5000 on the rear. Unfortunately, it did make the the rubber feel very slick to the touch. However, after a very cautious start, the traction felt normal and the slickness disappeared quickly from the rubber that made contact with the pavement.

It would be great if I could get the full tread life out of my tires. Is anyone using tire balm products and are they safe and effective?