My buddy Don is a dyed-in-the-wool hot rodder, and a professional engineer. I sincerely appreciate his perspectives on safe equipment, performance cars and all things mechanical and machinery related.
This post is used with his permission. He has informed me that he's signed up for steemit. I'll edit and tag him when he's registered.
On another social media platform Don wrote
"I follow several car related groups and see tires for sale regularly. But few seem to know some safety details about tires
Here we go....
Tread depth is measured with a treadwear gauge OVER THE WEARBARS!!!! If you look at a tread you should see a bit of rubber that’s not quite as deep as the tread. Those tell you when the tire has worn to the point of needing replacement. If you use a quarter between the wear bars the tire will appear to have more life than it actually has. There is a wear life note cast into the sidewall.
Google wearbars
Tires have a shelf life and date codes! Most tires are good for about five years but it varies by maker. Tires over ten years old are done. If you wanna roll your car buy really old tires!
There will be folks who will say ‘My tires were installed in 1970 n theys still got tread!’ But there’s more folks who have lost lives and hot rods by pushing the used tire envelope
Google tire date stamp
Rubber cracking does not always mean the tire is junk. ALL sidewall damage does mean the tire is unsafe, but if a tire is marked ‘regroovable’ cracks between tread rows is ok.
Have a pro havea look.
Tires are not round. There is a runout specification for each make but finding it is a beast. Rule of thumb is more that 1/16 inch is an issue. More important is shape and balance drift. If there’s a need for balancing within a month of rebalancing the tire is delaminating internally. If bulges appear and tread blocks are wedge shaped get thee to the tire shop!
Store tires on their sides with cardboard between them in a cool dark place. Remember they won’t last forever so if you are not gonna use em, sell, trade or give them away!
Happy hot rodding!"
Thanks Don, I appreciate your cogent post.