Join Date: Apr 2010
Location: Somewhere near Parkville, MO
You have two factors you have to consider. Mileage and age. Both are detrimental to the rubber. Three-Four year old tube, replace. 15-20,000 miles, replace. I re-used stock front tire tubes once. Rear tire tubes with stock tires could easily see 4 stock tires. Not so anymore with the CT where I re-used the tube that I had only one tire on, but would have changed it out this time as it had 25,000 miles on it. But that's only a 2 year old tube at the most so it won't get brittle with age.
I swapped to a Custom rim so I don't have tubes now on the rear now.