Weird exploding tires

"Anthony Giorgianni" <[email hidden]>
wrote in message
news:[email hidden]...

Quoted message said:

Hello All

Hope it's alright to cross-post this to these two groups.

I have a very strange problem all a sudden on my old, trusty Fiorelli 10
speed (I have a 23 lb alternative machine, but this old, heavy bike just
feels right). I just repacked the hubs and replaced the tires and tubes.
Though I have old steel 27 1/4 rims, I have for decades used 27 1/8 100lb
tires for the higher pressure.

This has never been a problem until now. I mounted the front tire about a
week ago (set to 105 recommended pressure on Avenir Discovery Korean-made
tires). That went fine. Today, I mounted the rear tire and brought it up

to

Quoted message said:

105. After about 5 minutes with the bike sitting by itself, the sidewall

on

Quoted message said:

the rear one literally lifts out of the rim, blowing out the new tube. I
decide to try again. This time I take it up only to 90 lbs. About 10

minutes

Quoted message said:

later... the exact same thing! The tire lifts out of a section of the rim

by

Quoted message said:

itself and the tube blows. I was down the block with a friend, and we

could

Quoted message said:

hear it happen with the bike in my house and the door closed. Sounded like

a

Quoted message said:

gun going off.

I can't figure out the cause. (I made extra sure that I did not catch any

of

Quoted message said:

the tube under the sidewall when I mounted the tire). I'm 49 and have been
riding this bike since I was 17. I never saw a tire pop out of a rim like
this on its own. Tomorrow I'll mount an old tire and my last tube, just to
see what happens. But has anyone seen this before? The only possibilities

I

Quoted message said:

can think of are:

1) Using narrower 1 1/8 tires in 1 1/4 rims? (Never been a problem before
... plus the front holds fine)
2) Some kind of defect in that rear tire
3) These are cheap tires with weak sidewalls or something. They were
inexpensive ($13). I've not used this brand before. But the front one

hasn't

Quoted message said:

blown at full 105 lbs
4) Something suddenly wrong with the rim? It looks ok.

Any thoughts appreciated, especially if you've seen this before. I hate
blowing out tubes and REALLY don't want to blow out one of my ear drums.
Fortunately, in both cases so far, I was well away from the bike.

Thx

From the Bicycle FAQ:

Blowouts and Sudden Flats:
http://www.faqs.org/faqs/bicycles-faq/part3/section-2.html

Thanks for posting that link .. and so quickly.

But nothing there seems to apply. There wasn't any heat. I didn't even get a
chance to try these new tires. And I used an old tube the second time. So it
couldn't have been the tube. But that page does make me wonder if there is a
defect in the bead of this new tire. Anyone seen that before , resulting in
a tire unseating itself?

--
Regards,
Anthony Giorgianni

Quoted message said:

Quoted message said:

From the Bicycle FAQ:

Blowouts and Sudden Flats:
http://www.faqs.org/faqs/bicycles-faq/part3/section-2.html

Anthony Giorgianni said:

Hello All

Hope it's alright to cross-post this to these two groups.

I have a very strange problem all a sudden on my old, trusty Fiorelli 10
speed (I have a 23 lb alternative machine, but this old, heavy bike just
feels right). I just repacked the hubs and replaced the tires and tubes.
Though I have old steel 27 1/4 rims, I have for decades used 27 1/8 100lb
tires for the higher pressure.

This has never been a problem until now. I mounted the front tire about a
week ago (set to 105 recommended pressure on Avenir Discovery Korean-made
tires). That went fine. Today, I mounted the rear tire and brought it up to
105. After about 5 minutes with the bike sitting by itself, the sidewall on
the rear one literally lifts out of the rim, blowing out the new tube. I
decide to try again. This time I take it up only to 90 lbs. About 10 minutes
later... the exact same thing! The tire lifts out of a section of the rim by
itself and the tube blows. I was down the block with a friend, and we could
hear it happen with the bike in my house and the door closed. Sounded like a
gun going off.

I had a similar experience with a different brand and size of tire;
what I concluded was going on in that case was that the rim involved
was built with the assumption that the tires would have a reasonably
well-defined bead, and not have flat sides in the area which is in
contact with the rim walls. Flat-sided tires work perfectly well on a
rim that has a shallow flange (though getting the tires on can be a
challenge if they don't have a deeper recess in the center), but they
can produce the type of behavior you describe if the rim has a deep
flange that can allow one part of the tire to climb up as another
drops down into the recess.

Once I'd figured out what was going on, I made sure to use only tires
that had a protruding bead on that rim. No further trouble.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Anthony Giorgianni said:

Thanks for posting that link .. and so quickly.

But nothing there seems to apply. There wasn't any heat. I didn't even get a
chance to try these new tires. And I used an old tube the second time. So it
couldn't have been the tube. But that page does make me wonder if there is a
defect in the bead of this new tire. Anyone seen that before , resulting in
a tire unseating itself?

Yes, it happened to me with a very cheap 26 inch x 1.75 tire on my
mountain bike/commuter. The tire was brand new and just too poor
quality. Cost about $8 at a bike shop. I tossed the tire and bought a
rather nice Kenda gumwall tire - still inexpensive, but it's a fine
tire, with no problems after many miles of rough commuting.
The tire bead was too soft and would not stay on the rim with only 50
psi. I'm agreeing with your analysis and thinking the tire is the culprit.
When you manipulate the tire, does the bead feel too soft? Does it
appear to be poorly finished along the bead edges? If yes, then maybe
it's time to raise the bar a bit, if you know what I mean!

Best regards, Bernie

Anthony Giorgianni said:

Quoted message said:

Blowouts and Sudden Flats:
http://www.faqs.org/faqs/bicycles-faq/part3/section-2.html

Quoted message said:

Thanks for posting that link .. and so quickly.

Quoted message said:

But nothing there seems to apply. There wasn't any heat. I didn't
even get a chance to try these new tires. And I used an old tube the
second time. So it couldn't have been the tube. But that page does
make me wonder if there is a defect in the bead of this new
tire. Anyone seen that before , resulting in a tire unseating
itself?

I think you missed the part of the tube lying under the tire bead.
This is the most common blowoff problem, especially when no braking
heat is involved. If the tire bead is not properly seated in the
hook of the rim sidewall, it will come off.

Jobst Brandt
[email hidden]

Anthony Giorgianni said:

Hello All

Hope it's alright to cross-post this to these two groups.

I have a very strange problem all a sudden on my old, trusty Fiorelli 10
speed (I have a 23 lb alternative machine, but this old, heavy bike just
feels right). I just repacked the hubs and replaced the tires and tubes.
Though I have old steel 27 1/4 rims, I have for decades used 27 1/8 100lb
tires for the higher pressure.

This has never been a problem until now. I mounted the front tire about a
week ago (set to 105 recommended pressure on Avenir Discovery Korean-made
tires). That went fine. Today, I mounted the rear tire and brought it up to
105. After about 5 minutes with the bike sitting by itself, the sidewall on
the rear one literally lifts out of the rim, blowing out the new tube. I
decide to try again. This time I take it up only to 90 lbs. About 10 minutes
later... the exact same thing! The tire lifts out of a section of the rim by
itself and the tube blows. I was down the block with a friend, and we could
hear it happen with the bike in my house and the door closed. Sounded like a
gun going off.

I can't figure out the cause. (I made extra sure that I did not catch any of
the tube under the sidewall when I mounted the tire). I'm 49 and have been
riding this bike since I was 17. I never saw a tire pop out of a rim like
this on its own. Tomorrow I'll mount an old tire and my last tube, just to
see what happens. But has anyone seen this before? The only possibilities I
can think of are:

1) Using narrower 1 1/8 tires in 1 1/4 rims? (Never been a problem before
... plus the front holds fine)
2) Some kind of defect in that rear tire
3) These are cheap tires with weak sidewalls or something. They were
inexpensive ($13). I've not used this brand before. But the front one hasn't
blown at full 105 lbs
4) Something suddenly wrong with the rim? It looks ok.

Normally, either the tube was trapped under the bead (in which case it
may not actually pop off until you put more air in or the bike is ridden
a few miles), or the rim flanges are splayed from hitting a big hole.

But you shouldn't use 1 1/8 tyres if the rims really are 1 1/4 - this
will make them pop off at a lower than usual pressure. The optimum
tyre/rim width ratio is something like 1.5.

What great responses I'm getting here. Great ideas.

After reading your response, Bernie, I went over to compare the bead with
what's on my last tire (ISO Tech 2). It feels the same, BUT the sidewall on
these new ones seems tissue paper thin, especially where the light-colored
sidewall meets the black tread. I wonder if that's the problem, though I
wonder why the front one isn't slipping out.

I'm also wondering if Zog is right, that I shouldn't be using a narrower
tire. But I've never had problems with this before.

Regards,
Anthony Giorgianni

860-529-3308
Email: [email hidden]
Web page: www.giorgianni.homestead.com

"Bernie" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Yes, it happened to me with a very cheap 26 inch x 1.75 tire on my
mountain bike/commuter. The tire was brand new and just too poor
quality. Cost about $8 at a bike shop. I tossed the tire and bought a
rather nice Kenda gumwall tire - still inexpensive, but it's a fine
tire, with no problems after many miles of rough commuting.
The tire bead was too soft and would not stay on the rim with only 50
psi. I'm agreeing with your analysis and thinking the tire is the

culprit.

Quoted message said:

When you manipulate the tire, does the bead feel too soft? Does it
appear to be poorly finished along the bead edges? If yes, then maybe
it's time to raise the bar a bit, if you know what I mean!

Best regards, Bernie

Thanks for the response Zog

Are you certain about that width issue???? I always thought it was fine to
use slightly different size widths. And this web site I just found seems to
agree ...
http://www.sheldonbrown.com/tire_sizing.html

I hate to go back to 1 1/4 (that IS what the rim says) because I can't find
any high pressure tires in that size. Also, I didn't even get a chance to
ride on this tire before it unmounted itself twice, so even if the size
isn't optimal, its seems unlikely that's the problem. But if you really
think it is, I guess I could go back to the 1/4s instead of the 1/8s :O(

As far as catching the tube under the bead, I'm always very careful with
that. When I first mount a tire, I always watch to see if the bead lifts any
when I start to put in air for the first time - a sure sign that tube is
caught under the bead. But after the tire unmounted itself the first time, I
was especially careful - blowing up the tube slightly and pinching the bead
slightly to double check that the tube wasn't caught anywhere.

--
Regards,
Anthony Giorgianni

The return address for this post is fictitious. Please reply by posting back
to the newsgroup.
"Zog The Undeniable" <[email hidden]> wrote in message
news:4125a37a.0@entanet...

Quoted message said:

Anthony Giorgianni said:

Hello All

Hope it's alright to cross-post this to these two groups.

I have a very strange problem all a sudden on my old, trusty Fiorelli

10http://www.sheldonbrown.com/tire_sizing.html

Quoted message said:

Quoted message said:

speed (I have a 23 lb alternative machine, but this old, heavy bike just
feels right). I just repacked the hubs and replaced the tires and tubes.
Though I have old steel 27 1/4 rims, I have for decades used 27 1/8

100lb

Quoted message said:

Quoted message said:

tires for the higher pressure.

This has never been a problem until now. I mounted the front tire about

a

Quoted message said:

Quoted message said:

week ago (set to 105 recommended pressure on Avenir Discovery

Korean-made

Quoted message said:

Quoted message said:

tires). That went fine. Today, I mounted the rear tire and brought it

up to

Quoted message said:

Quoted message said:

105. After about 5 minutes with the bike sitting by itself, the sidewall

on

Quoted message said:

Quoted message said:

the rear one literally lifts out of the rim, blowing out the new tube. I
decide to try again. This time I take it up only to 90 lbs. About 10

minutes

Quoted message said:

Quoted message said:

later... the exact same thing! The tire lifts out of a section of the

rim by

Quoted message said:

Quoted message said:

itself and the tube blows. I was down the block with a friend, and we

could

Quoted message said:

Quoted message said:

hear it happen with the bike in my house and the door closed. Sounded

like a

Quoted message said:

Quoted message said:

gun going off.

I can't figure out the cause. (I made extra sure that I did not catch

any of

Quoted message said:

Quoted message said:

the tube under the sidewall when I mounted the tire). I'm 49 and have

been

Quoted message said:

Quoted message said:

riding this bike since I was 17. I never saw a tire pop out of a rim

like

Quoted message said:

Quoted message said:

this on its own. Tomorrow I'll mount an old tire and my last tube, just

to

Quoted message said:

Quoted message said:

see what happens. But has anyone seen this before? The only

possibilities I

Quoted message said:

Quoted message said:

can think of are:

1) Using narrower 1 1/8 tires in 1 1/4 rims? (Never been a problem

before

Quoted message said:

Quoted message said:

... plus the front holds fine)
2) Some kind of defect in that rear tire
3) These are cheap tires with weak sidewalls or something. They were
inexpensive ($13). I've not used this brand before. But the front one

hasn't

Quoted message said:

Quoted message said:

blown at full 105 lbs
4) Something suddenly wrong with the rim? It looks ok.

Normally, either the tube was trapped under the bead (in which case it
may not actually pop off until you put more air in or the bike is ridden
a few miles), or the rim flanges are splayed from hitting a big hole.

But you shouldn't use 1 1/8 tyres if the rims really are 1 1/4 - this
will make them pop off at a lower than usual pressure. The optimum
tyre/rim width ratio is something like 1.5.

Anthony Giorgianni said:

Today, I mounted the rear tire and brought it up to 105. After
about 5 minutes with the bike sitting by itself, the sidewall
on the rear one literally lifts out of the rim, blowing out
the new tube. I decide to try again. This time I take it up
only to 90 lbs. About 10 minutes later... the exact same
thing! The tire lifts out of a section of the rim by itself
and the tube blows.

Are you using hooked rims:
http://www.sheldonbrown.com/gloss_h.html#hook

I was first alerted to this problem when using Conti
TravelContact tyres. The sidewall of these states "Mount only
on hooked rims".

John

This reminds me of the time I tried installing a new tube and tire on
my first good wheel, not so long ago. Being quite inexperienced, I
pinched the tube between the tire and the rim. When I pumped it up to
about 105 psi, the tube exploded like a shotgun. Birds flew up around
me, dogs began barking, etc. Hard on the ears, too. It opened a
3-inch gash in the tube and I had to junk it. So I took the tire and
wheel into the bike shop at the local REI store and paid them to
install a tube and the tire. While I was browsing around the
merchandise waiting, I heard a similar loud BANG from the repair shop.
A minute later, the mechanic sheepishly came out to the floor to pick
up another tube for my wheel.
I felt much better about my own mistake.

Anthony Giorgianni wrote in message
<[email hidden]>...

Quoted message said:

Thanks for the response Zog

Are you certain about that width issue???? I always thought it was fine to
use slightly different size widths. And this web site I just found seems to
agree ...
http://www.sheldonbrown.com/tire_sizing.html

I hate to go back to 1 1/4 (that IS what the rim says) because I can't find
any high pressure tires in that size. Also, I didn't even get a chance to
ride on this tire before it unmounted itself twice, so even if the size
isn't optimal, its seems unlikely that's the problem. But if you really
think it is, I guess I could go back to the 1/4s instead of the 1/8s :O(

As far as catching the tube under the bead, I'm always very careful with
that. When I first mount a tire, I always watch to see if the bead lifts

any

Quoted message said:

when I start to put in air for the first time - a sure sign that tube is
caught under the bead. But after the tire unmounted itself the first time,

I

Quoted message said:

was especially careful - blowing up the tube slightly and pinching the bead
slightly to double check that the tube wasn't caught anywhere.

1 1/4 rims are not HP compatible, put more than 80psi and you will blow off
any tyre. 1 1/4 tyres have rubber on their bead making them adhere to the
rim wall, HP tyres are a cloth finish, relying on a vertical rim sidewall to
prevent unseating. Aramid fibre beads require crochet hook type rim to
retain them, no matter what pressure used.

Trevor

Interesting Trevor. But would the tire say to use only on hooked rims?

I've been running 100 pounds tires forever on these rim, mostly recently
Trek Iso Tech 2 100lb and never had a problem like this. The bead and
material used on these Avinir tires 1 1/8 105 lbs seems the same as on the
Treks, which I've probably run for five years at 100 lb. Have I just been
lucky?

--
Regards,
Anthony Giorgianni

The return address for this post is fictitious. Please reply by posting back
to the newsgroup.
"Trevor Jeffrey" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

Quoted message said:

1 1/4 rims are not HP compatible, put more than 80psi and you will blow

off

Quoted message said:

any tyre. 1 1/4 tyres have rubber on their bead making them adhere to the
rim wall, HP tyres are a cloth finish, relying on a vertical rim sidewall

to

Quoted message said:

prevent unseating. Aramid fibre beads require crochet hook type rim to
retain them, no matter what pressure used.

Trevor

Anthony Giorgianni said:

What great responses I'm getting here. Great ideas.

After reading your response, Bernie, I went over to compare the bead with
what's on my last tire (ISO Tech 2). It feels the same, BUT the sidewall on
these new ones seems tissue paper thin, especially where the light-colored
sidewall meets the black tread. I wonder if that's the problem, though I
wonder why the front one isn't slipping out.

I'm also wondering if Zog is right, that I shouldn't be using a narrower
tire. But I've never had problems with this before.

I don't know about the narrower tire element, but I just googled your
Avenir Discovery tires, and they look pretty good. I doubt the thin
sidewall has anything to do with the tire slipping out of the rim.

Good luck and if you find the answer, please post it.
Bernie

Having your face close to the "shotgun" blast at the moment of explosion
may be hard on much more sensitive parts than your ears. Complacency
during those high pressure inflations can put an eye out.

A friend of mine broke busted a tube and cornea when a (poorly fitting)
new tire blew out at about 60 psi. Make sure your tires are matched to
rim type and diameter, and the rim walls aren't worn or deformed. Some
eye or face protection wouldn't hurt, either, whenever you're not sure of
the fit.

Good luck,
David

"flatline" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

This reminds me of the time I tried installing a new tube and tire on
my first good wheel, not so long ago. Being quite inexperienced, I
pinched the tube between the tire and the rim. When I pumped it up to
about 105 psi, the tube exploded like a shotgun. Birds flew up around
me, dogs began barking, etc. Hard on the ears, too. It opened a
3-inch gash in the tube and I had to junk it. So I took the tire and
wheel into the bike shop at the local REI store and paid them to
install a tube and the tire. While I was browsing around the
merchandise waiting, I heard a similar loud BANG from the repair shop.
A minute later, the mechanic sheepishly came out to the floor to pick
up another tube for my wheel.
I felt much better about my own mistake.

Thanks Dave

It's funny you said that. Years ago I had a valve go (saw a bubble growing
off the edge of the valve a split second before it burst). I ended up with
tinnitus in one ear for about a week. (I'm a musician/composer, so I can't
have that) I DO try to keep my head as far back as possible when I'm adding
air now. Actually, first time the tire blew this week, I intentionally had
left the bike outside for a little while. I figured they were new tires, 105
psi, why take a chance. And I kind of thought to myself: "This is a little
silly, isn't it?" Then sure enough, a few minutes later, it sounded like a
gun going off.

When I tried the wheel a second time, a friend came over. I told her what
happened. So we were sort of walking far away from the bike. I decided to
put the air in in several stages and was up to 80 pounds. Then I brought it
up to 90 out of 105, and we decided to go for a walk. That's when I put the
bike in the house. We were down the block when we heard it go. Pretty scary
actually. After reading Trevor's post last night, I decided to take the air
out of the front one. It was fine for a week, but I don't want to take a
chance that one is going to let go while I'm sleeping!!! I'd have a heart
attack :O(

The bike shop has asked me to bring in the tires and rims, so we'll see.
I'll post back.

--
Regards,
Anthony Giorgianni

The return address for this post is fictitious. Please reply by posting back
to the newsgroup.

"Dave" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Having your face close to the "shotgun" blast at the moment of explosion
may be hard on much more sensitive parts than your ears. Complacency
during those high pressure inflations can put an eye out.

A friend of mine broke busted a tube and cornea when a (poorly fitting)
new tire blew out at about 60 psi. Make sure your tires are matched to
rim type and diameter, and the rim walls aren't worn or deformed. Some
eye or face protection wouldn't hurt, either, whenever you're not sure of
the fit.

Good luck,
David

Thanks Bernie

The bike shop has asked me to bring in the rims and tires. I'll post back
once I find out anything.

--
Regards,
Anthony Giorgianni

The return address for this post is fictitious. Please reply by posting back
to the newsgroup.

"Bernie" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I don't know about the narrower tire element, but I just googled your
Avenir Discovery tires, and they look pretty good. I doubt the thin
sidewall has anything to do with the tire slipping out of the rim.

Good luck and if you find the answer, please post it.
Bernie

Anthony Giorgianni said:

Thanks for posting that link .. and so quickly.

But nothing there seems to apply. There wasn't any heat. I didn't even
get a chance to try these new tires. And I used an old tube the second
time. So it couldn't have been the tube. But that page does make me
wonder if there is a defect in the bead of this new tire. Anyone seen
that before , resulting in a tire unseating itself?

If you caught the tube under the tire bead you could have a blowout like
that with a new or a well-used tube. It's easy enough for you to check
that when you're starting to inflate the tire. It's more likely that
you're using a new tire that isn't compatible with the rim - many tires
these days require hook-bead rims, and will blow off on the old style
rims. I'm betting this is your problem.

Regarding 27 x 1 1/4 vs 27 x 1 1/8 - back when 1 1/8 first came on the
market I used them with great success on the same rims I'd been using for
1 1/4 tires. Of course, back then 75 psi was high pressure.

"Anthony Giorgianni" <[email hidden]> wrote
in message news:[email hidden]...

Quoted message said:

Hello All

Hope it's alright to cross-post this to these two groups.

I have a very strange problem all a sudden on my old, trusty Fiorelli 10
speed (I have a 23 lb alternative machine, but this old, heavy bike just
feels right). I just repacked the hubs and replaced the tires and tubes.
Though I have old steel 27 1/4 rims, I have for decades used 27 1/8 100lb
tires for the higher pressure.

Old steel rims are really bad in the rain. They almost certainly lack hooks,
so high tire pressure is unreliable. I'd buy some new wheels (or rims,
anyway).

Anthony Giorgianni wrote in message ...

Quoted message said:

Interesting Trevor. But would the tire say to use only on hooked rims?

I've been running 100 pounds tires forever on these rim, mostly recently
Trek Iso Tech 2 100lb and never had a problem like this. The bead and
material used on these Avinir tires 1 1/8 105 lbs seems the same as on the
Treks, which I've probably run for five years at 100 lb. Have I just been
lucky?

Aramid fibre is used on 'folding tyres', especially useful on folding rims
:-), steel beads are used on most 'wired' tyres. If it is a folding tyre,
it should say on the box and on the tyre not to use without the hooked rims
as there is otherwise nothing to constrain the bead from lifting at one
point whilst it flexes. If they are steel beaded tyres there is some other
problem. I would suggest that the rim may need cleaning, any waxy coating
should also be cleaned from the tyre bead.
Perhaps the Trecks are a tad wider, enough to make a difference. I
really suspect it is a waxy coating on the bead.

Trevor