Used tires, how can I be sure that they are roadworthy?
Aside from looking at the general appearance, how do I properly inspect the tire(s)?
Are there any scenarios, (damage has occurred), where I should absolutely avoid using the tire?
Make no assumptions about the tire(s). They could be on a vehicle or laying on the ground.
Since the tire is used, having a way to check the tread depth is going to be important, and if you are buying a set of two for a single axle, make sure you can get two that have the same amount of tread so you don't put extra strain on your differential (assuming driven wheels). If you're getting one tire, try and match the remaining tread on your existing tire. Note that 2/32" is considered a totally worn tire, and many tires will start in the 12/32"-10/32" range when new.
As far as damage goes, pay attention to any repairs that have been done, and if any, make sure it was a proper repair, and not some roadside plug. Look for cuts along the tire that may not have lead to a flat, and look at both sidewalls of the tire for abrasion or damage.
Inspect the tire bead (inside edge) to make sure it's in good condition since a used tire has, by definition, been on and off of a rim. Any time the tire is put on a mounting machine is a chance for damage by an inexperienced operator.
If the tire is free of damage, we also need to see when the tire was made.
The tire should have a stamp like the one in the bottom right of this image. The tire in the image was made in the 51st week of 2007. The last for digits have been standardized, so you can rely on the date code. If the tire is older, look for signs of the rubber hardening or cracking. If the code is not present, the tire may have been made before 2000, and you don't want that anyway.
Used tires, how can I be sure that they are roadworthy?
Asked what vehicle they came from if possible.
Aside from looking at the general appearance, how do I properly inspect the tire(s)?
Make sure no bulges exist:
Make sure the tire's are not dry rotted:
Look to see if any metal is showing on the inside or surrounding of the tire or if it has several patches as that would indicate it's had a flat before:
Make sure the tread is in good shape and not showing wear:
If replacing tires ask if they have a pair of them as it does help prevent damage your vehicle.
Are there any scenarios, (damage has occurred), where I should absolutely avoid using the tire?
I've always looked at used tires as a temporary solution if Im running low on cash and I need something better than I have or for a rim that I plan to use if I run into a flat as I hate the donut and prefer a full size tire.
