How do you know when a tire needs to be replaced?

[Digital Gee]

Duh, I mean I realize if it's got a big hole in it, that's too obvious.

I'm running Continental Gatorskins on Ruby, and have about 1,500 miles on them. Couple of flats along the way, but the tires look fine. What I've never heard discussed is the typical lifespan of a tire, and/or the telltale signs that it's time for a replacement. (I tried putting a dime into the tread to measure how deep it goes, but that didn't work. :D )

So what is the expected useful lifespan of nice tires, and how do you know they're wearing out and should be replaced?

[Tom Bombadil]

Not sure, but I can't wait for the "What kind of tire should I buy" thread to start.

My tires all have tread, so when the tread wears down, it's obvious.

[buelito]

once you can see the casing under the rubber--it's time... if you have a lot of skid marks and it feels really thin, it might be time...if you have 5000 miles on them, it might be time...if you have continual (vary vague term) flats, it might be time...if new tires are on sale, it might be time...

I have a 'rule' that I tend to stick with...if the bike is used regularly, I try to change the tires every year. That works on my road bike and the fixie. The mountain bike will probably keep the tires until the rubber rots :)

train safe-

[Pat]

DG

Generally I replace a tire when it has used up most of its rubber. I used to ride until the casing showed but that was probably pushing the envelop slightly. I think my tires resented this and tended to show the tread on the first 10 miles of a century.

[ken cummings]

For me tires last 3 to 5 thousand miles. Of course replaced when thread shows though in one area that had very clean streets I got down into the second layer of the carcass before I felt any need to change them. Also if I get two flats on the same commute run I get new tires. It is not worth being late to work and getting fired because I am too cheap to get new tires.

[Mojo Slim]

DG,

I use Gatorskins on my Giant OCR. I routinely get 2500 miles on the rear, 3000+ on the front. Once I got 5000 on the front, but I think I pushed it a bit. As the tires get thinner, flats may become more frequent.

[Trsnrtr]

They are toast when the cord shows. I'm not going to go search for it, but I read on one tire manufacturer's web site that the rubber is just a wearing surface and that the cords/belts are where the flat protection is and there is no reason to replace a properly wearing, cut free tire until the cords show.

[Digital Gee]

Thanks for all the insight! Helpful stuff!

[Tom Bombadil]

I was in a bike shop a couple of months ago when a guy brought his bike in to replace both his front and back tires. He said they only had about 500 miles on them, but the day before he was riding at 20+ when a car cut in front of him. He had to emergency brake, skidding several feet on the pavement. When the tires rotated, he saw that all of the rubber was gone & he could now see the casings on both tires. I slide over and looked and sure enough, a small patch of missing rubber on both tires.

He said as mad as he was at that driver when he was cut off, he was even madder a minute later when he saw the damage to his tires.

I never imagined you could eat away that much rubber on a single stop.

[Long deKlein]

When the center of the tread starts to flatten, it means the end is nearing--close inspection before every ride is a good idea, if you don't already do that. As mentioned by other posters, when the belt under the tread starts to show through, it's replacement time, unless you're one of those "living on the edge" types. My Michelin Carbons are showing noticeable flattening at only 1500 miles--think my next pair will be black chili Conti 4K's.

[dvs cycles]

On the GP-4000 there are two little hole like dimples that are tread wear indicators. I replace just as they are almost gone. I always put the new tire on the front and rotate front to rear then toss the rear.
Have gotten over 5000 mile on several tires doing this.
The Gatorskins that came on our tandem got 2200 miles on the rear before it was getting that flat spot of wear on the tread that said replace me or I will get a flat.
Gp-4000's ride and roll much better than the Gatorskins.

[CrossChain]

Besides wear, there's tire damage: too many deep cuts in tread or strange bulges, tears, or contusions in sidewall. I change tires more often for gouges and dings than because I'm down to the casing. But I often ride some lousy, country roads.

[dendawg]

... if you have a lot of skid marks


I thought that was time to change your shorts :-)

[Paniolo]

Rear tires always wear faster. You will get 2-3x longer on the front. I used to buy 3 tires figuring 2 rears and 1 front, but often the front was still pretty good. Best way to maximize miles as mentioned above is rotate front to rear and put new one on front ... plus best tread is always on the steering wheel. Though often I'm too lazy to actually do this! ;)

Obviously a ton of factors go into it, but I usually get 2-2500 out of a rear. Casing showing is a dead giveaway. Getting frequent flats on a higher mileage tire is another. I usually go by when the crown of the tire gets nice and flattened out ... say 3/4" or so across the crown is flattened out. Notice how the crown on a new tire (or your front) is nice and rounded. If you have the tire off you can definately feel how much thinner it is when it gets to that point.

[Trsnrtr]

As always, when a question on bike maintenance comes up, consult the Master.

On tire rotation: http://www.sheldonbrown.com/tire-rotation.html

On when to change a tire, you'll find it near the bottom of this page:

http://www.sheldonbrown.com/tires.html

[doctor j]

Interesting topic. I was talking to my LBS guy about tires today. Mine are plain jane Kendas that came on Ol' Fuj when I got him last March. 2,959 miles so far. No problems at all. There's still some tread on them as well. Given the problem-free nature of these tires, I'd like to get another set exactly like them.

[stapfam]

I think the Flat area across the tyre is a good indicator of the amount of rubber left. Had a shock on Boreas as most of my tyres do get a lot of milage- In the 000's before I even look at them. However the Vrederstein Fortezzias I had on Boreas were showing a definite flat on the front tyre after 500 miles. Looked at the rear and it was flat across the contact area. Got replacements and taking the tyres off- the rear must have been very close to the Canvass.

The best indicator has always been when the tyre goes Bang. Get the most out of your equipment.

[Tom Bombadil]

So DG, you've had two flats on Ruby. What is your current approach to addressing flats? Are you carrying equipment to attempt to fix a flat mid-ride, or is it still a cellphone-based process?

[Digital Gee]

So DG, you've had two flats on Ruby. What is your current approach to addressing flats? Are you carrying equipment to attempt to fix a flat mid-ride, or is it still a cellphone-based process?

I carry the tools, the pump, the tube, and the cellphone. Just in case. :D

[BluesDawg]

Add a patch kit and you've earned your merit badge. ;)

[Digital Gee]

Add a patch kit and you've earned your merit badge. ;)

I will patch at home, thank you very much! Something to do while watching Law and Order reruns... :)

[BluesDawg]

I will patch at home, thank you very much! Something to do while watching Law and Order reruns... :)

I do my patching at home too. The patch kit on the bike is just in case I also get a flat in the spare. I rarely have to use it. More often I have loaned it to others to use. All part of being prepared.

[megaman]

A few years ago I had a stone cut a large hole in the center of my high presure Kenda Kwests. Of course I was in the middle of nowhere. I used a large patch for the tire. I still continued to put 100 lbs. in the tires until about 800 miles later the patch started coming through the casing. My lbs guy said he couldn't believe I could get that much more life out of that tire just by using a large patch. If I have a flat I alway patch the casing right away.

[CrossChain]

If I can find the puncture without taking off the wheel, I usually patch on the road. No need to take the wheel off front or rear, just unseat the tire, pull out the section of tube, patch, pump, and go.