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Can worn tires contribute to pinch flats?

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Can worn tires contribute to pinch flats?

Old 12-09-15, 04:19 PM
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Can worn tires contribute to pinch flats?

I rode more than 30 years without ever getting a pinch flat. But I've had 4 this year, 3 in the past two days

Incompetent installation seems unlikely as 3 of those 4 flats were preceded by a couple thousand trouble free miles and my installation track record over the years is solid. Low inflation was a factor because it's been really slick lately and I sometimes will drop 20-30 psi for extra grip. In all cases, the flats resulted from me hitting something hard. Lots of things to hit in the dark here and I don't baby my wheels.

Since I've historically had no problems with pinch flats, I'm wondering if the sudden uptick in problems indicates another factor at play since my riding habits have been consistent? I used to replace my tires much more religiously, but roads where I live are clean enough that I squeeze more life out of them than I used to.
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Old 12-09-15, 04:37 PM
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Originally Posted by banerjek
[h=2]Can worn tires contribute to pinch flats?
I've never seen pinch flats happen due to worn tires.[/h]
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Old 12-09-15, 04:38 PM
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I don't see how. Pinch flats occur at the other side of the tire, at the interface with the rim, not near the road.
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Old 12-09-15, 04:45 PM
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Super old with worn and rotting sidewalls...maybe. In other words, +2 or no.
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Old 12-09-15, 04:46 PM
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The Drop did it.

drop 20-30 psi
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Old 12-09-15, 04:54 PM
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Agree that the drop in pressure likely was the cause. I can see extremely worn tires maybe having a small influence. I've had tires that are tough to mount new and even resorted to levers. After many miles those same tires can go on and off with just my fingers. That's mostly from sidewall give. So maybe the lack of sidewall stiffness had just a little to do with it.
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Old 12-09-15, 05:10 PM
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Originally Posted by StanSeven
Agree that the drop in pressure likely was the cause. I can see extremely worn tires maybe having a small influence. I've had tires that are tough to mount new and even resorted to levers. After many miles those same tires can go on and off with just my fingers. That's mostly from sidewall give. So maybe the lack of sidewall stiffness had just a little to do with it.
I also think the same, but dismissed the sidewall effect as a very small fraction of the pressure effect. In short the pressure is the culprit.

No offense intended OP, but your whole riding scenario is terribly conceived: riding slick streets through a high level of road hazards in the dark, not to mention a cavalier attitude toward protecting your tires. Could you devise a better recipe, not just for pinch flats, but for a really serious problem. I think you have been incredibly lucky. IIWY, I would quit while I was ahead.
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Old 12-09-15, 06:01 PM
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Originally Posted by 10 Wheels
The Drop did it.

drop 20-30 psi
That's what I am thinking.
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Old 12-09-15, 06:33 PM
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Any extra weight lately?

Eyesight still sharp?
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Old 12-09-15, 07:19 PM
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I was getting a rash of pinch flats, and then figured out what was happening. Problem was two fold.

I normally check pressure daily, or at least every other ride. I was getting lazy and skipping this step. Doing the old "look down on the rear tire when in the saddle" thing, and if I saw too much sidewall I would break out the pump. Just being lazy.

I also had a run when playing with low pressure, and eventually had to bring it back almost to where I always rode with the Conti Grandprix.

No pinch flats in like 3 years.

ETA- to answer the question, I know for sure worn tires are more prone to flatting, but from puncture. Pinch flats, I don't know .

Last edited by Erzulis Boat; 12-09-15 at 07:28 PM.
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Old 12-10-15, 07:50 AM
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I've never seen a relation to pinch flats vs worn tires either, but then I've had very few pinch flats like you.

serious here--if your eyesight isnt as good as it was, perhaps you are missing stuff and hitting things a bit harder--we all know body stance and unweighting at the right split second makes the world of a diff of how much force goes into hitting a pothole or whatever.

I realize that I don't notice debris as well as I did X years ago, eyesight, and so am making a connection with your issue. Im over 50 though so who knows about you.
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Old 12-10-15, 11:21 AM
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20-30 psi is a big drop. Either you had way too much pressure before, or you now have too little. Given the pinch flats, I'm voting for too little. Add 10-15 psi back and call it a lesson learned.
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Old 12-10-15, 11:26 AM
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BTW, what tires, width, and your weight and bike weight, added panniers on bike?

Enquiring minds want to know
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Old 12-10-15, 12:35 PM
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Originally Posted by rpenmanparker
No offense intended OP, but your whole riding scenario is terribly conceived: riding slick streets through a high level of road hazards in the dark, not to mention a cavalier attitude toward protecting your tires.
Sounds like a winter commute to me. Unfortunately for wheels and tires, it can be really hard to road hazards in those conditions. You focus on not getting thrown off the bike by the big pothole, not so much trying to avoid it (hard to avoid what you can't see).

That said, I never worry about dropping tire pressure in the rain and never have any real traction issues. I also can't remember ever getting a pinch flat, perhaps one when I first started cycling.
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Old 12-10-15, 11:20 PM
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Some of these would help.

https://www.compasscycle.com/shop/co...8-barlow-pass/
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Old 12-10-15, 11:34 PM
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You need bigger and grippier tires. If your bike doesn't allow it, it really doesn't suit the riding you actually do. I can totally relate to dropping that much pressure. I do it. But I first make sure I am riding big tires. If I do this on a ride with say 25s, I just hope this won't be an expensive ride. I've stopped riding 23s. They can get scary.

(I will soon get back my "new" bike that will handle any tires. Looking forward to bombing around on 38s.)

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Old 12-10-15, 11:37 PM
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Originally Posted by joejack951
Sounds like a winter commute to me. Unfortunately for wheels and tires, it can be really hard to road hazards in those conditions. You focus on not getting thrown off the bike by the big pothole, not so much trying to avoid it (hard to avoid what you can't see).
Ever heard of lights? How can you miss a pothole? I can see hitting a rock but if you're running into potholes you probably need better lights.
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Old 12-10-15, 11:44 PM
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Every once in a while I'll get a pinch flat. Last one was last fall. I think I hit a branch that had fallen across my driveway.

I doubt bald tires have much to do with it. Mine are getting mighty bald.

Low pressure, yes.

Also, dark nights and more debris on the road from winter storms.

My good light was stolen, so lately I've been using a headlamp that barely illuminates the road. I thumped over a couple of branches on my way back home on my last trip. Fortunately no pinch flats, but I decided to stop and throw them off the shoulder. Did we get some more wind Anyway, it never hurts to clean off some of one's road hazards.

If you're worried about grip, perhaps try some grippier tires.
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Old 12-11-15, 06:11 AM
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Originally Posted by gregf83
Ever heard of lights? How can you miss a pothole? I can see hitting a rock but if you're running into potholes you probably need better lights.
Let's see: rain, lots of oncoming traffic, maybe a little fog on the glasses because it's 35° and I'm a little over-dressed. I don't know. Ride at night in the rain enough and it will happen. I have an 800 lumen Light & Motion Seca headlight. Plenty of light in almost every situation but it doesn't keep potholes from hiding under what looks like a little bit of water when you have a bunch of headlights in your eyes.
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Old 12-11-15, 07:05 AM
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Originally Posted by joejack951
Let's see: rain, lots of oncoming traffic, maybe a little fog on the glasses because it's 35° and I'm a little over-dressed. I don't know. Ride at night in the rain enough and it will happen. I have an 800 lumen Light & Motion Seca headlight. Plenty of light in almost every situation but it doesn't keep potholes from hiding under what looks like a little bit of water when you have a bunch of headlights in your eyes.
Yup, we've all had it happen due to stuff like that

PS you're still being coy about the details...
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Old 12-11-15, 08:06 AM
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If I read it right you had a pinch flat earlier this year, rode a couple thousand miles, another flat two days ago and then two more since then. I'd suspect something unusual is going on.

In practical terms, I'll disagree with the consensus in that 20 pounds less pressure doesn't make pinch flats that much more likely. 30 pounds though I personally get cautious and avoid abrupt bumps and running over things, because that's when I start getting pinch flats. Reading between the lines of the original post, I take it that you don't change your habits at that reduced pressure. So I'm going to say that random chance has caught you when you were at your most vulnerable. And because of the short time frame maybe you accidentally got it even a little lower on the last two, a pressure misreading or the valve wasn't tightened.

Just thinking theoretically, the pressure in the tires serves to allow the sidewalls to support the bike's weight. So worn tires could be a factor, but I think only if the sidewalls had somehow gotten worn or degraded. That hasn't happened in my experience though, and believe me I ride tires down to the bare thread. Maybe you have racing tires with very supple sidewalls? Do those degrade after time?
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Old 12-11-15, 08:47 AM
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Originally Posted by joejack951
Let's see: rain, lots of oncoming traffic, maybe a little fog on the glasses because it's 35° and I'm a little over-dressed. I don't know. Ride at night in the rain enough and it will happen. I have an 800 lumen Light & Motion Seca headlight. Plenty of light in almost every situation but it doesn't keep potholes from hiding under what looks like a little bit of water when you have a bunch of headlights in your eyes.
I guess I ride the same routes enough that I know where the bumpy sections are and don't ride through those blind. I'll ride down a bridge at 50kph with very poor visibility in the rain but I know there aren't any potholes.

For the OP: I switched to 28mm tires this year which seems to have eliminated pinch flats for me. I used to get them occasionally as I'm not always diligent about pumping up my tires. With 28s I can go a month without pumping my tires. Much more forgiving riding over debris.
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Old 12-11-15, 09:24 AM
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Originally Posted by gregf83
I guess I ride the same routes enough that I know where the bumpy sections are and don't ride through those blind. I'll ride down a bridge at 50kph with very poor visibility in the rain but I know there aren't any potholes.

For the OP: I switched to 28mm tires this year which seems to have eliminated pinch flats for me. I used to get them occasionally as I'm not always diligent about pumping up my tires. With 28s I can go a month without pumping my tires. Much more forgiving riding over debris.
NOVICES: Do not emulate this practice. Pump your tires before each ride.
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Old 12-11-15, 11:40 AM
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Originally Posted by rpenmanparker
NOVICES: Do not emulate this practice. Pump your tires before each ride.
If you're having to pump 28mm tires before every ride you've likely got a leak that needs fixing.
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Old 12-11-15, 12:01 PM
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Banerjek, come on, fess up, what tires, what widths, what pressures, what rider and bike weight......spill da beans buddy
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