Gman1958

Continental Gatorskins 700x28 on my 1983 Specialized Sequoia
strange rear tire tread wear with what appears to be bumps along the center of the tread line.
I verify about 112 psi prior to every ride.
I am 6-3 and about 215 lbs.
I would love to know what might be causing this
I cannot upload any pictures due to forum rules about minimum of 10 posts.

Litespud

Hard to tell without pics, but in the forum tradition of answering a question that wasn't asked, 112 psi seems awfully high for a 28mm tire and a rider weight of 215 lb. I wonder if you dropped the pressure a bit, thereby achieving a wider contact patch, would wear be less concentrated on the centerline of the tire?

base2 

You said it: Continental Gatorskins.

I have had several Gatorskin tires fail in this manner. I'd like to think it was age & wear, but sadly the most catastrophic was a 559x28 that had under 500 miles use. It just bubbled up, tore up & let the tube let the air out.

My longest lasting Gatorskin was around 3500 miles & the casing pattern was obviously visible. It was no surprise when chunks of rubber started coming off.

Still though, tire tread should wear evenly & stayed glued all the way down to nothingness.

Here, check out this Gravelking if you'd like to feel better about your situation. Less than 300 miles:

700x38c Panaracer Gravelking by Richard Mozzarella, on Flickr

I can't say if there is any rhyme or reason to failures like this other than to posit that manufacturing pressures for speed & efficiency at any cost might lead to compromises between quality & risk assesment.

A tire should work with out failure at the recommended pressures. Period.

Take your tire back to the store or contact Continental customer service.for replacement. It might not work, but it may be worth a try...At the suggestion of forum members here, it worked for the Panaracer above & a replacement tire arrived about a week later.

Having said that, if you need 110 psi, to avoid pinch flats, or whatever, you might want to try the next tire width up & running a pressure more sensible. The reason is, you have the rim to be concerned with as well. Psi is literally force times area. More area inside the casing of a larger tire means less pressure can still generate enough force to stress the center channel & bead seats causing premature cracking/failure. The larger tire affords you more elevation between rim & offending object reducing pinch flat risk at a given pressure. Also less driving force to drive a piercing object into the tire.

I've found that quality made & properly inflated 32's, 35's, & 38's aren't necessarily slower than 23's & 25's...but that's just my experience & like anything there are limits where you tip back over the edge to the other side to niticible inefficiency again.

mack_turtle

where are yo riding this bike? smooth roads, gravel paths, dirt, trainer?

cxwrench

Pressure is wayyyyyy too high. May or may not have anything to do w/ your issue, but wayyyyy too high. Try somewhere in the 80's.

Iride01 

It's a valid policy to help with SPAM on the site.

It doesn't mean you can't just simply write the URL to the location of your pics in the plain text of your message. You'll have to remove the https:// and change the "." before .com or what ever to " dot ". If the spam filters still balk, do some further obfuscation and we'll figure it out. If the site you post the pics to uses a share function, then use that URL it generates.

As for pressure way too high... not if it's below the max PSI listed on the side of your tire. Others get too concerned with what they think the correct tire pressure should be for your ride weight. And they don't really know because they don't ride the same roads as you ride. Nor are they you.

mack_turtle

if running the tire at a certain pressure means the weight of the bike and rider are concentrated in a bit of tread so narrow that it prematurely wears a flat spot on the center of the tire in short order, it's very likely that the pressure is unnecessarily high.

Bmach

Might not have anything to do with the problem, but I agree tire pressure is high. I’m 225 and run 90/85 with 700x25.

cxwrench

No need to know any of this. If 100psi is not enough you need bigger tires not more pressure. If you don't have room for appropriate tires you bought the wrong bike.

Iride01 

The OP was not asking for tire pressure advice. The current Gatorskins on Continentals site say 95 to 116 PSI. So there is no reason to expect tire pressure as the cause of the problem.

I run my 25 x 622 GP 5000 at 100 /120 PSI front/rear. I prefer the smaller contact patch on the very smooth roads I ride. And my legs feel better after riding any distance at those pressures than when at lower pressures. I know, I've tried lower PSI on many occasions. Always the same result for me, I have more energy and am ever so slightly faster at higher tire pressures.

I won't tell you that you need to run a certain pressure. You should be able to figure out what works best for you.

base2 

Agreed. I think most here, myself included addressed pressure in an earnest attempt to be helpful in a general sense so that the OP will entertain different & perhaps more appropriate tire size choices in the future.

Gman1958

thank you for the reply... the pic is at

photos.google dot com/photo/AF1QipNLXuQgKSAC77LzNrs-5jMpBjLgbfY6ww68JAvj

Gman1958

wow! My tire isn't that bad... on someone's advice to try and share the photo from google

photos.google dot com/photo/AF1QipNLXuQgKSAC77LzNrs-5jMpBjLgbfY6ww68JAvj

Gman1958

Regular well maintained county roads that provide a bike lane. To reiterate, I didn't have this problem with two previous sets of Gatorskins.

Gman1958

Thank you... I have been riding this particular Specialized Sequoia since I bought it new in 9/1983, so there have been several sets of tires. My practice of riding at 112 psi on these feels fine and rolls nicely. I am always worried about pinch flats etc. where the risk is higher at lower inflation pressure.

cxwrench

112 psi in a 28 is about the same feel as a little over 130 psi in a 23. That can't feel good. Why are you worried about the occasional pinch flat?

Carbonfiberboy 

Our tandem team weight is 283 + the extra tandem bike weight, maybe another 12 lbs. We run a true 28mm tire at about the OP's pressure, never a problem. We run a true 32mm at 95. That latter combo produces essentially the same pressure on the rim and ride comfort as the OP's tire and pressure. It's just a matter of choice and usually fork model. We've toured on 28mm at 115, no problem other than it was a bit rough on the cobbles. I agree about the pinch flats, but guess that the OP could run a little less pressure, but it's all fine if he doesn't want to do that. It's one thing to talk big and quite another to be responsible for someone hitting a pothole on a descent and pinch flatting. Our tandem with those pressures will roll right over one without a problem, not a huge one, but good sized. Have done. They're not easy to see in mottled light. A riding buddy of mine pinch flatted on an unseen pothole, went down, and was badly injured.

All that said, I wouldn't run a tire at greater than max sidewall pressure and haven't. IMO&E max tire pressures are associated with tire width in such a way that their combination will not produce a greater force than a rim in fair condition will tolerate.

I've also had tires with unexplained cord breakage producing weird tire shapes at much lower pressures on a single bike, old Conti tires not made anymore.

Andrew R Stewart 

The rhythmic bulging of base2's tire suggests a casing belt issue. Andy

Koyote

The url is not working for me. And yes, I did replace "dot" with an actual dot.

andrewclaus

The OP mirrors my tires, pressures, and riding style almost exactly. Just yesterday I was repairing a punctured tube, for maybe the third time in 5000 miles. I could still see the tread wear indicators and the tires look fine. This is my fourth set of Gatorskins in eight years or so--I have strong brand loyalty and many miles of experience with these. If I ever had a problem like this (though I can't see the photo either), I'd complain to Continental.

davidad

Useful tire pressure is a function of vehicle weight (rider , bike and gear). You will have a little more comfort and slightly lower rolling resistance at the lower pressures.
Frank Berto-calculation Based Tire Pressure Calculator (roubert.name)

Iride01 

Yep, not for me either. Google photo's seems to be a hit and miss for me too when I try to link a photo from there.

Just to be certain though the OP needs to be sure that the URL was copied from the share function and not just what was at the top of their browser.

Gman1958

"Why are you worried about the occasional pinch flat?"

I have always understood that higher tire pressure provides more resistance to compression and a subsequent pinch flat...
I actually did suffer a pinch flat last June when I was test riding this
same bike and tires at 95 psi

Gman1958

I understood that lower pressure results in more rubber contact, thus more rolling friction/resistance.

Gman1958

I have completed 10 posts... here is another attempt to upload pictures of my tire story...