When to replace a tire?

[dmp221]

It's common wisdom that, on automobile tires, a reasonable measure of having a safe amount of tread is the penny trick.  Insert a penny, Lincoln-head in, into the tread.  If you can see the top of Abe's head, it's probably time to replace the tire.
Does the same hold true on our motorcycle tires?

[Cal Price]

Depends a lot on your local laws (and coins) generally speaking a bike tyre (sorry tire) needs less depth of tread than a car t.re. They usually have a little stud marker at marked places in the tread to indicate when to change, this varies from place to place so I'm sure someone local will give you the exact depth required. A good general rule is if you are thinking about it, its probably due.

[dmp221]

I know about those wear-bars in tires.  I guess what I'm really interested in is how much tread remains when those wear-bars start to show through?  I see a lot of bikes that look really close to bald, yet the wear-bars haven't shown up yet.

[pizzleboy]

If you see lining, replace it, glad to be of service.

[JohNLA]

I cannot currently see the wear bars on mine but the tire is starting to sqaure in the middle and at some points there is no tread left. I have run other tires down to the steel The result was a blow out. Luckily, I was only doing 10mph at the time but it still sucked.
Maybe, I am getting old but if it looks questioable just go ahead and replace it. I also love the feeling of a bike with new tires on it. It's like buying a new bike.

[Cal Price]

I'd go with "If its questionable replace it" You do NOT want a blow out. I've not had one one but once saw some poor sod on a motorcycle combination take a blow-out at speed, up a bank and reverse summersault. Remember new tyre(s) can be slippery for up to about 500 miles but much better than worn down slick.

[rcepluch]

Tire depth is normaly measured in 32ths of an inch.  Wear indicators are supposed to show at 2/32".  This is the usual standard for determining replacement.  

Some suggest that you replace mc tires at 3/32", but to me that seems like alot of good thread left.

The best way to measure tire depth is with a tire depth gauge.  These are very simple devices and easy to use. They only cost about $5.  Go to a good auto parts store because some of the chain stores do not carry them.

The suggestions that if you are wondering if you need a tire you probably do seems to be accurate.  I checked my tire when I thought it was getting thin and it checked out at 2/32" or less.

[TheGoodGuy]

i guess I got to replace mine.

I saw those knobbie things on my tire, i didnt kjnow what they were.. now i know it was the tyre wear indicators.

I have 9100+ miles on my tyres, the rear tyre can probably do another 1000 if i need be.. In wet conditions I better replace or i will hydroplane.

I found it did square off a bit but its gotten back to be round again. I got some tread on teh sides though.. So i still have some grip on teh turns. Center part is running out of tread.

[conradvr]

Given the fact that the tyres are these two important rubber bands that keep you uprite I don't shirk on their maintenance.  The rules I use for tyre replacement are (and when ever feasible I try replace both at the same time and always use the same brand and model):

1. If any part of the tyre tread is at the wear markers or less than 1.5mm (0.06") front, 2mm (0.8") rear.  Typically the centre of the tyre will reach the markers before the sides.

2. The tyre starts to look tired or old.  The properties of the rubber changes over time and is dependant on contaminatiosn picked up on the road, environmental conditions and rate of use.  The rubber can become 'plastic' like, more slippery and lose its 'rubberness'.  They can also tend to start showing cracks and gaps.  Some tyres 'go off' earlier than others - some tyres tend to start scalloping/feathering towards their lifes end.

3. The tyre has been damaged or punctured.

4. The profile of the tyre adversley effects handling.  A lot of straight up riding results in a squared off tyre that can make cornering more difficult.


In summary tires are my insurance policy for safe and fun riding and get checked before every ride.

Cheers
Conrad