jdishner

I rode for years and years without flats. I finally get one in my rear tire and the tire itself was nearly worn through so I decided to get a replacement tire. My wheels are about 15 years old or more, "ARAYA 700C Japan" the original ones that came with my Schwin Paramount. The bike shop I went to had only a couple of tires in the size I had - 700 x 25, after they showed me the first one I asked if they had a better one. I'm thinking that if I spend more money on it it will be better. The guy tells me its a folding tire - I ask what the difference is, he says not much. I ask if it will be faster, he says yes. So the tire I get is a Origin8 Elimin8er 2 and the guy installs it for me. Leave in in my trunk untouched for about two weeks and when I go to take it out and use it its flat. I replace it with a spare that he sold me, went for a ride and after turning around at low speed it went flat. Replaced it with another spare, it lasted one trip but never seemed to have enough air in it. Now on my first tire I was putting about 110 to 120 ppi in the rear tire - but couldn't see what the rating was on the side of the tire because it was worn off. On this new tire it says 100 psi max so that's what I've been filling it to but it never seems to have enough pressure. I did a few searches and a lot of people said it was ok to over inflate the tires a bit.
After the third spare blew I went to a different bike shop and had them put a new tube in and inflate and mount it for me. Replaced the tube lining too - just to be sure that wasn't the problem. Lasted for one ride, but the pressure again feels dangerously low - when riding at 28 - 30 mph it feels like the tire isn't giving me much grip and that its going to roll over on me. Today I go to top off the air pressure in the tire and figure I'd try putting it to 105 psi - and a block out the tire blows out. The tube has a long split down the middle about three inches long. So here's my questions:

1. Are folding tires worse than standard tires? Are they not able to handle as much air pressure or did I just buy a bad brand/tire?
2. Am I right in thinking I need to buy a better tire that can handle 110 - 120 psi so that I can ride like I have been used to for years?
3. What am I missing? What am I doing wrong?

Thanks for your help...

Retro Grouch 

1. Half of your tire/rim interface is rim. If your rim doesn't have a hook bead seat or if your tires fit poorly on your rim, don't expect your tire to hold the amount of air pressure that the tire indicates. I'm 90% certain that a 15-20 year old 700c rim will have a hook bead seat. 90% isn't 100%.

2. When you install tires, it's important to be sure that no part of the inner tube is caught between the tire bead and the rim. That sounds simple but pinching the tube under the tire bead is easy to do and it happens all the time. When that happens it's possible for the tire to hold air for a period of time and the to blow out unexpectedly. Time taken to be sure that the tube isn't caught under the tire bead all the way around the tire on both sides is time well spent. That's especially true if you're in a hurry because it greatly lessens the likelihood of having to do the job twice.

3. The difference between a folding tire and a non-folding tire of the same model is the bead material. A folding tire has a kevlar bead that folds and a non-folding tire has a steel bead that doesn't fold. Steel weighs more than kevlar. Either holds air pressure equally well. I think that steel beads are easier to install but some other people think the opposite. folding tires cost more.

4. The only things that I know about your situation is what you posted. Based on that my guess is that you pinched your inner tube under the tire bead. And yes, it's entirely possible that a bike shop mechanic might pinch the inner tube under the bead when installing a new tire.

Bill Kapaun

I just installed a pair of 26MM tires on identical rims (to yours) yesterday.
I used tubes designed for 26-32MM tires.
IT was a PITA to not have the tube folded on itself.
First time I experienced that.
Possibly you are using tubes for the "next larger size" and don't want to spend the extra 20 minutes (I seriously spent that much extra time messing with the **** thing) trying to get the tube straight?

I'd installed the identical tires & tubes on a 20MM wide hybrid rim and had zero issues.

My recomendation is to use a tube that has to "stretch" a bit.

davidad

https://www.adventurecycling.org/res...SIRX_Heine.pdf

jdishner

First off thank you all for answering my question. I haven't had the time to address this issue since I originally posted it. I really appreciate the willingness to help and the real answers youve given me. I am going to get a different tire altogether because I don't like the folding tire and the kevlar band - it just doesn't feel right to me, it seems like it's not holding the air as well as the traditional steel band did to me. I also think the tubes I was using were too big because they were almost falling out of the tire when I was putting it in.
So I am going to get a new tire that has the steel rim and try to find one that is rated for 120 PSI like the last one I had. So, thanks again guys, I will post after I make the attempt, I really look forward to riding again!!!

Looigi

If you've ridden on the road many years without a flat, you're either incredibly lucky or don't ride much.

The bead and the tire itself don't contribute to holding air in because there are many places it can leak out, spoke holes, around the valve stem, etc. The tire is responsible for restraining the tube and the tube is responsible for sealing air in. Foldable tires are every bit as reliable as non-folding tires and used by the vast majority of riders.

Flats are cause by punctures in the tube, either from sharp objects, getting pinched against the rim when riding over a sharp-edged hole/obstacle, or getting pinched between the bead of the tire and rim during installation. The main thing a tire can do with respect to puncturing is being more resistant to cuts or penetration by road debris. Some are better than others, the main tradeoffs being increased weight, harsher ride, and less traction.

jdishner

I think the biggest issue I was having was using a tire that was too large and was getting easily pinched. The tire that I had said it was only rated to 100 PSI and I typically have 110-120 - so that was the biggest reason for wanting to get a non folding tire - that and its easier for me to change a steel band tire than the folding one. Thank you for the input Looigi!

canam73

In reading the OP's post it sounds like in at least some of the cases you are talking about a slow leak and not a blow out. Modern road tubes tend to loose air over time. If they are 'lightweight' butyl or latex they will loose air faster. Checking and topping off tires before rides is pretty standard fare. Now, if you are starting a ride on a fully inflated tire and ending it on a squishy one, that's another story.

On your blowouts, it still sounds like a tube issue and not a tire one, unless your for some reason your tire doesn't seat properly or you are pinching the tube when you install it.

As Looigi said, the bead material shouldn't have a direct effect on what you are talking about and in modern tires most of the better ones will be folding bead. But that said, Origin8 isn't really a tire company and those are probably a re-branded CST or other low grade tire.

DieselDan

Check the rim tape/strip. Having used the bike for many years without a flat, then having several in successive rides and after a bit of storage, may indicate rim tape in sore need of replacing.

You could just send the bike to me. I'll fix it, then test ride it until it has the problem again in two or three years.

Kimmo 

It's not the kevlar bead's fault it was a faulty tyre. Or perhaps you managed to damage it. A tyre with a kevlar bead is likely to be hi-po tyre, with not a lot of rubber to protect the carcass, and consequently it'll be a lot more supple, which makes it fast and grippy. You may not be used to such a tyre; people who ride sew-ups for the first time often say they feel flat, because the supple casing doesn't transfer as much energy into the wheel, but a given pressure will protect the rim just the same. Supple tyres are faster - the extra speed comes from lifting bike and rider less, plus the tyre returning more of the absorbed energy onto bumps and the back of the contact patch. It takes a little while to get used to the apparent contradiction, but it's win/win/lose - the hassle of getting a flat. Although Stan's tubeless goop is meant to make sew-ups a practical proposition... Anyway, I ride a bike that's basically what a pro's training bike looks like, as a commuter. Mid-range 23mm tyres (thinking about a 21 for the front at my -lack of- weight), and I ride it like a bike courier - over things, and stuff. Rarely get a flat (maybe once a year or so?), so I see no reason to ride heavier tyres.

Oh, it occurs to me that depending on your weight, you might have been better off with a narrower tyre; the light-bulb shape of a tyre much wider than the rim makes for squirmy cornering... if you're around 75kg or less, you can get away with a 23 on the back.

If it's one of these, it's hook bead.

Kimmo 

dp

DannoXYZ 

Some contradictory information. Tyre-pressure should be chosen based upon tyre-size and weight so that you have roughly at 15% sink-rate. This is a good balance between rolling-resistance, comfort and puncture-resistance. The larger the tyre, the lower the pressure can be for any given weight to get the 15% sink.

As for slow-leaks, it really depends upon numerous factors. The thickness of the tube being primary factor. Many shops are staffed by enthusiastic racers who think that thin lightweight fast-rolling tyres and tubes are the only way to go. But for non-racers and commuters, you're better served with a heavy-duty thick tube and touring-type tyre. The kevlar vs steel-bead doesn't have anything to do with your issues in this case.

Al1943

A steel bead tire is not going to fix the problem. Kevlar beads have become the standard and in my opinion are superior to steel bead.

Be sure you have good rim strips (tape) to protect the tube from the spoke holes. If any part of a spoke hole is exposed to the tube the tube will extrude into the hole and fail. Velox rim tape of the correct size is your best option.

Blowing a little air into the tube before installing in the tire will help prevent the tube from being pinched. Using my mouth, what I can blow into a 700 x 23 tube is just right.

With the tire mounted but not inflated push the valve stem back into the tire. This will help the bead seat in the area near the valve.

Be sure to fully inflate the tire and tube before EACH ride.

Bill Kapaun

My CHEAP 26MM folding tires have a max PSI of 140.

Steel bead doesn't guarantee higher pressure.

jdishner

@canam73 - Yes in some cases it was a slow leak - this was typical so each time that I would go out for a ride wether it had been one day or a week I would refill the tires to between 110-120 PSI. I did notice on the last pair of tires I purchased (and had one installed at the shop) they are lightweight tires. Sometimes the tires would be a little squishy at the end of the ride but not typically. The problem Ive been having this summer is the back tire will go flat after a block of riding (most recently) or after I ride over a metal - strip slightly elevated above the pavement (2nd time) or just after slowly turning around (1st time).

I agree that it does sound like I am pinching the tube when installing it, I am going to purchase a smaller tube and try that - I believe I am using a 28mm tube and not a 26mm tube as Bill suggested.

As for the bead material I was getting frustrated with the lack of success and attributed some of the failure to the tire. I am probably pinching the tube with the bigger tube size and the material I am unfamiliar with. I am certainly more comfortable with the steel band and I want to purchase one that is rated to 120 psi anyhow. Thank you!

jdishner

@DieselDan - I did have the rim tap replaced the last time I took the tire to a bike shop for a new tube and had them install it so I figured that it would be put on correctly. So frustrating.

I appreciate your generous offer to repair my bike and ride it for a few years, I will certainly consider that as a last resort.

jdishner

@Kimmo - That is the exact wheel that I have except the color is aluminum, perhaps the camera altered the color?

I hated the way this tire cornered - I ride along the Bike Trail in Chicago along lake Michigan, and there is a long straightaway that has a gentle slope to it and with this tyre and 100 psi I felt very loose, as if I could lose balance at any time. I usually use 110-120 psi and when I did attempt to put that much air in this tire it popped. Incidentally I am about 79kg.

I do not know what size tire I am using or what I had before - I wish I did. I cant see what size I'm using on the front tire because the writing has worn off the sides. I'm not sure what size the folding tire I bought is, but I'm thinking I should probably bring the tire on the front in with me so I have a better chance of getting a similar tire. Thank you for responding!

jdishner

@ DannoXYZ - The article link that was posted makes the same point about tire pressure. In my case I don't have an ultra fast bike anyways and I'll gladly trade a little speed for no flats, or at least less flats. I just need it to work!!

jdishner

@Al1943 - good advice - I do think I was causing a lot of the problems by pinching the tube and by using too large of a tube as well. Thank you.

jdishner

@ Bill - thanks for the info - I now know what I am looking for! Something that is rated to a higher PSI, probably something narrower or at least matching what I have on the front, and I'll probably get steel just because I prefer it. Thank you!

Kimmo 

Yeah, it's silver; crappy phone cam makes everything orange in low light. Never seen these rims in colours, they're about the most boring non-steel rim possible.

At your weight I'd advise a 25 on the back and a 23 on the front, somewhere between 90-110psi.

Here's a hot tip you may find hard to believe: identical rims and/or tyres front/rear = lazy spec.

rekmeyata

Yaking about sink rates etc is just weird, there is no way to measure sink rate so your guessing as to what the sink rate is. Why not just use a tire pressure calculator? I know why, because it doesn't sound intelligent enough! Michelin has put the standard formula for proper tire pressure vs weight vs tire size that's been around for at least 40 years into a handy dandy easy to use calculator; see: https://www.dorkypantsr.us/bike-tire-...alculator.html Use only the middle calculator and use your totally clothed (riding kit) body weight, and your totally ready to ride bike weight including full bottles. This calculator is right to within 5psi!! Some people like a firmer feel but should not exceed 5psi above the recommendations, some like it bit softer and should not go below more then 5psi of the recommendations.

If you find the calculator exceeds your tires recommended air pressure for the tire you're using that simply means you're too heavy for the size of tire you're using and you should go up at least one size depending on what the calculator says once you increase the tire size by one.

Are you doing something wrong? Probably, most people over inflate their tires, this actually has been proven to decrease performance and wear tires out faster. You may discover that you don't even need 120psi tires!!!

Kimmo 

Pffff... think harder.

So, minus the inclination to check against measured tyre compression, how have you verified that?

jdishner

@ Kimmo - I'm not familiar with the term lazy spec what does that mean? What is the advantage of the 25 on the rear? Better handling?
Thanks for your help I appreciate it!

jdishner

@ rekmeyata - I've always just eyeballed sink rate - just fill it up and sit down and it sags a little. I have gained a little since I last purchased a tire (before this recent folding one that I've had the problems with) so going with a 25 is probably a good idea. I was able to drop down to 110 PSI on the front and it was fine - I used to ride with 120 psi and it was probably too much, thank you for the link!