tread depth

[26667]

what's the best/easiest way to measure tread depth? Just stick a ruler into the groove and try to eyeball horizontally? And outside of "when it's past obvious" what's a good rule of thumb for minimum?

My rear Conti at about 6K is starting to show wear (sadly, at the center stripe only).

[sumran]

When they manufacture the tire, they include some thin bars that run perpendicular to the tread. They are supposed to indicate a minimum safe tread for that tire. If it is worn down to the bar, the tire should be replaced, according to the manufacturer.

The old standard for cars was alway the penny test. Put a Lincoln head penny in the tread, with Abe standing on his head. If you can see all of his hair, time to change the tire. I guess that works for motorcycles as well.

[pffog]

$1.99 at any auto parts store should buy you a tread depth gauge.

[dduelin]

If I am not mistaken 2/32" is the DOT standard for minimum tread depth and the aforementioned wear bars or TWI's (tire wear indicators) are positioned at 2/32" tread depth remaining, at least in the USA. This is a tad less than 2 mm. Lincoln's hair is about 2/32" from the edge of a penny but a more exact method is the tire gauge also previously mentioned.

[sumran]

[QUOTE=dduelin;466704 This is a tad less than 2 mm. previously mentioned.[/QUOTE]

Lincoln had a son named Tad.:whistle Not relevant, but true.

[Geoff]

Been kinda wondering the same thing myself. I'm seeing the center groove on the rear tire (Metzeler Lasertec) gradually disappearing yet no sign of the aforementioned wear bars. I like to stay safe, but I would also like to get the maximum life out of the tires. Maybe I should lay off the throttle a bit?

[carockwell]

If the tread disappears entirely, you need to replace the tire. No telling when the cord will show up. Of course, it is usually wiser to replace the tire before this. A little known California law trivia. In the old days before radials and car tires only lasted 15, 000 miles, the CHP could issue you a fix it ticket for driving a car with no tread. They could issue a moving violation (more serious-counts on your record) if the tire's cord was showing and could demand the car be towed. I don't think there are any CHP officers who know this any more.

[26667]

wear bars!!! are there two "uuuuh's" in Duh? It's been so long since I owned a bike that needed a tire, I'd just completely forgotten.

Abraham Lincoln is my favorite president. tho' from this vantage he might have let a couple few of those states go ahead on.:browand PS, the Doris Kearns Goodwin bio, "Team Of Rivals" is a terrific book!

But while we're at it, would you venture an opinion about whether about 7K on a rear tire is "about" ballpark, give or take, what one might expect...given all the myriad variables? I never used to really keep track, just sorta waited for the dealer to tell me I needed a tire along with a major insp.:german