Most bad used tires give themselves away if you know where to look. Take five minutes per tire, use your phone flashlight, and check both sides. Here is what we look for when a customer brings tires they bought online to our garage in Laurel, South Edmonton.
Walk away: these are not safe to run
- Bulges or bubbles on the sidewall. A bulge means the internal structure is damaged, usually from a pothole or curb hit. It can fail without warning. There is no repair.
- Cuts or gouges deep enough to show cords (the fabric or steel threads inside the rubber).
- Plugs or patches in the shoulder or sidewall. Industry repair standards limit repairs to the tread area, with punctures no larger than 6 mm (1/4 inch). A repair outside that area is not acceptable.
- A plug with no patch. The accepted repair is a plug to fill the hole plus a patch on the inside liner, done with the tire off the rim. A plug pushed in from outside is a temporary fix at best.
- Exposed steel belts in the tread.
- Bead damage. The bead is the edge that seals against the rim. Torn, kinked or chunked beads will not seal properly.
- Tread at or below the wear bars. See Tread depth.
Think twice: price these down hard
- Fine cracking (dry rot or weather checking) on the sidewall or between tread blocks. Light surface crazing on an older tire is common. Deep cracks you can fit a fingernail into are a walk-away.
- Age over about six years. See How to read a tire's date code.
- Uneven wear across the tread, which lowers the usable life.
- Mismatched brands, models or ages within a set of four. On all-wheel-drive vehicles, mismatched tires can be a bigger problem. Check your owner's manual.
- A proper repair in the tread area. A correct plug-and-patch is fine, but we would still want to see it from the inside and you should pay less for it.
How to check, step by step
- Confirm the size and date code on the sidewall.
- Run your hand slowly around both sidewalls (watch for wires). Bulges are easier to feel than see.
- Look into every groove for nails, screws and plugs.
- Measure tread depth inside, centre and outside.
- Look at the bead edge all the way around.
- If the tires are on rims, look at the rims too: bends, cracks, curb rash and corrosion where the tire seals.
Some damage only shows on the machine
Some damage is only visible once the tire is off the rim or spinning on a balancer, like inner liner damage from being driven flat, or a hidden belt shift that shows up as a wobble. That is why we inspect every tire again before we mount it. If we find something, we stop and show you before going any further.
When you bring your own tires, you are responsible for what you bought. We will always give you our honest read on condition, and we may decline to mount a tire we believe is unsafe.