ModelTFan01

I am not a bike fan, but instead as my username suggests I am a Model T Fan. For you that don't know what a Model T is, it's an automobile produced from 1908 to 1927 by Ford Motor Company.

I do ride my bike to get exercise. It's a 1981 Free Spirit "Pinnacle" bike. I've been told it's a racing bike, which I guess is the same as a road bike. It has those weird handlebars that I still don't understand and can't get used to.

Anyways I've had problems with the rear tire. When I bought the bike at a garage sale in 2011 and got it for $20, it was in good condition. However, it wasn't a month before I got a flat tire on the front tire and the original 1981 tire/tube in the front had to be changed out. He also changed the 1981 tube in the rear tire also, but didn't change the tire.

The tire lasted until this year when it finally gave up the ghost and almost blown up on my adding air into it. It didn't pop, but the tire and tube was changed to a weird Chinese Tire brand.

Anyways it wasn't a week until the 1st Chinese Tire got a hole in the outer tire and the tube went through it. Even though this sounds like a stupid reason to puncture a tube, I grabbed a sharp paper clip near me and popped the tire. I didn't want it popping.

That tire/tube was changed to another Chinese Garbage Tire. It's been pretty good up until now. Today it was a little low and decided to go over to a friend's house to put air in it (I don't have a pump or air compressor.) I put the recommended 90 pounds in it, and visited with my friend for a few hours until I got back on it.

When I got back on it, I got about two blocks before I suddenly heard a big "BANG!" I was riding my bike down a hill on the sidewalk (the street is dangerous where it popped, so I ride on the sidewalk.) It scared me, but wasn't all that loud and it sounded like those guns they shoot to signal runners to run. I looked down to these kids down the hill from where it happened and they were looking at me. I then knew it wasn't a gun, but thought my tire got punctured.

It got more than a puncture. It had a blowout. You can tell that the tube pushed the tire out and the tube got stuck between the tire and the rim. You could also see the big split in the tube clear as day.

Before I left my friend's house, I made sure that nothing was wrong and that everything was alright and nothing was pinched. Everything checked out fine at his house. I know I put 90 pounds in there because the pump had a gauge on it that said it had 90 pounds. I know there was nothing wrong in the sidewalk/road because my front tire didn't pop.

I didn't see what the tire/tube looked like before it blew. However, I can see where it pushed the tire out and got pinched.

I have a question. I just put air into the tire a few hours before this happens. Nothing's wrong and the tube's not pinched. What could and did go wrong? It also had a little below the maximum tire pressure, which was 90 PSI. I had between 87 and 90 PSI in that tube.

However, when I did see the tube, the tube was bent in like a "V" shape where the valve stem is. But how would this cause a problem?

Also, the guy who installed this is named Chuck and he works in Boonville, Missouri. I personally don't recommend him. The tire's and tubes he's put in it hasn't lasted a year!


Please help! I will get another dude to install the tubes or may install the next ones myself. I will get photos tomorrow.

10 Wheels

Most of the time blowouts with the loud bang are caused by the tube being pinched between the tirebead and the rim.

It sometimes happens to most of us.

ModelTFan01

This bang wasn't really loud, but enough to scare me and the kids down the hill.

The tube wasn't pinched. I made sure of that because a couple years ago my grandpa was inflating a 40 PSI tire and the tube got pinched and it popped.

Like I said, I'm a Model T Fan. Model T's have the same type of tires (clincher/beaded edge) as a bike and a Model T Tire requires a tube. Model T's have the same tire/tube design but bigger.

10 Wheels

Post a pic of the tube.

ModelTFan01

I will tomorrow.

The tube is a Kenda. I personally dislike Kenda, all made in China. All Kenda makes that's good is bike tires, but the worst tubes.

The tube split down the middle, right on the seam. What would cause a blowout?

10 Wheels

This is one blew out on my front wheel at 17 mph.
Loudest bag I ever heard.

ModelTFan01

I wasn't going really fast.

I however was going a good 10 miles per hour. This bike has seen a lot of use. I sometimes go up to 15 miles on this bike daily some weeks.

The tube however, like I said, was bent in a "V" shape at the Valve Stem?

Also, what brand of Tube/Tire do you recommend to use? I'll get photos tomorrow.

ModelTFan01

Any ideas on what caused the blowout?

chasm54

It is always possible that the tube was faulty. It's more likely that you failed to install it properly and trapped the tube between the tyre and the rim. This can be done without being obvious.

If one owns a bike, one should own a bicycle pump. It's ridiculous to have to go to a friend's house every time a tyre needs inflating,

I doubt very much, from your account, that you'd want to follow any recommendation I would make for tyres, because I'd likely pay twice as much per tyre as you paid for the bike. But if you tell us the size of the wheels you are using I'll, give it a go.

Mos6502

In my experience this problem (if it is recurring) usually indicates a problem with the rim itself, not the tires or tubes. Does the rim have any "blips" in it or other signs of damage?

I once had what looked like an ok rim, but the tire wouldn't seat properly and the tube would bulge out and blow even at half of the max pressure indicated on the tire. Despite everything seeming straight and true, I replaced the rim and the problem went away. I kept the same tires, and same brand of tubes.

Also for others in this thread, since it is a Free Spirit it likely has 27" wheels. I have noticed a problem lately with tubes in this size actually being too big for the wheel so that they bunch up when inflated which can also lead to leaks, but not to blow outs that I know of.

wahoonc

Does the bike have steel or alloy rims, are they hook edge or smooth edge rims? If smooth edge a higher pressure tire is not going to stay seated above about 70psi. Pictures of the rims wouldn't hurt. It is very easy for a tube to puncture due to roughness on the rim too.

Aaron

OldsCOOL

Flats happen. All roadies know and accept this.

If you are experiencing multiple flats before you get to the end of your street, then you have a problem. Otherwise....choose a tire and tube of your liking and install it.

Kinda like Model T's, isnt it??

(what you experienced on the blowout is a lifting of the tire bead from too much pressure or a weakness of the tire bead/rim clinch. you dont need to inflate to 90 if that is the max psi)

big chainring 

Exactly. Old steel rims can't take the high psi. - 70psi max.

Homebrew01

Yup, my thoughts too. Those old steel wheels were not meant for high pressure tires.

BlazingPedals

That's from a pinched tube. or a tire that fits too loose on the bead. Either way, the tube was not supported by the tire. Tubes by themselves cannot hold 90 pounds of pressure; they need the tire's cords for strength.

Edit: after reading subsequent responses, yes the rim might have something to do with it. Steel rims had a 'rolled' bead which doesn't hold the tire as tightly as the modern hook-bead that modern aluminum alloy rims have. Tires used to have a warning molded right into the sidewall, "use with hook-bead rims only." My old 1973 Raleigh Record had steel rims, and it could only take 65 psi.

ModelTFan01

I got some photos today.

It's likely that it came from a pinched tube, but it is possible as I just pumped up the tire about an hour or two before it happened.

The tube is a Kenda. The rim is a clincher/beaded edge. Will post photos later.

ModelTFan01

The image below is of the tire itself.

Where my finger is located is where the split in the tube is.

The split in the tube.

The Kenda logo along with the serial number.

The Kenda Logo w/ SN.

The bike itself.

The tube out of the bike tire.

The tube out of the bike tire and the Schrader Valve.

Blurry image trying to get a picture of where the tire buldged.


Click on a image to view a bigger image.

OldsCOOL

It's not the tube's fault. Most likely the bead lifted off the rim due to over inflation. Many have discovered that you can run a 12.00 tire and a 3.00 tube just like you can ultra expensive ones.

ModelTFan01

I doubt overinflation. The tire had 90 PSI in it, which is the maximum pressure.

If it was overinflated, why didn't it pop within those two hours I was at my friends house?

JanMM

Just because the tire has a 90psi max inflation pressure doesn't mean that it will stay on an older steel rim - is that a steel rim?

Lots of decent tires/tubes and other bike parts are made in China, by the way.

ModelTFan01

I have to inflate it to 90 PSI because the front tire has 70 PSI and it's uncomfortable riding with a front tire having more air than the rear.

In order to do this comfortably, I would have to have the rear at 70 and the front at about 45 PSI. IDK about 45, but I have a feeling that the tire would be flat with that.

50 and 70 wouldn't work.

My last tire that was original to the bike had 75 in the rear and 70 in the front. I think I'll do that next time. 70 in front, 75 in rear.

xenologer

judging by the shinyness of the photos, your bike has old steel rims

the modern tire is rated to 90, but the old rims are only rated to 65
you have to go by the Lowest rating for things to work together

as for why didn't they blow out immediatly after inflating but only after 2hours when you rode it? because you weren't riding it yet; weight of rider and the action of rolling was the last straw.

stay at 65psi
it sucks, i know, they feel flat all the time
thats why the design is considered obsolete
you can either live with it or change to modern aluminum hooked rims designed to take higher pressure

ModelTFan01

Good to know! When I get a replacement tire/tube, I will tell him that.

If he over-inflates it up to the 90 PSI, I'll just deflate it back to 65. I'll let a little air out of my front tire (which has 70) tomorrow. I'll have 60 in my front and 65 in the rear.

Will a little flat tire (65 psi in a 90 PSI tire will probably feel and look flat) hurt any thing?

OldsCOOL

It wont look flat at all. As for the feeling, that depends on how much you ride with the acquired familiarity and are able to tell the difference. At 65psi you will have a comfortable ride.

Only the very high PSI racing tires have a prescribed minimum for safety and performance issues.

ModelTFan01

So it will be okay if I have 65 PSI in it?

The front tire will be 10 PSI lighter, and the rear will be 25 PSI lighter. I know the front won't look or feel any different really, but the rear is 25 PSI lighter, that's a huge difference!