Veloflex Beads

[daniel]

Why does my bead keep popping out on my rear veloflex tire? I have
never had this problem until today when it happened twice in two
different spots on the rim. I have done nothing to the rear wheel
recently...

 

[[email protected]]

On 28 Mar 2007 21:51:25 GMT, [email protected] wrote:

>Carl Fogel writes:
>
>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>> never had this problem until today when it happened twice in two
>>> different spots on the rim. I have done nothing to the rear wheel
>>> recently...
>
>> A bad tire?
>
>> Higher inflation?
>
>> A brake-worn rim slowly spreading?
>
>That rims spread is not my experience although they appear to do so
>because their cheeks wear hollow, so that exterior rim walls slope
>outward. As I mentioned, I have ridden MA-2 rims to less than 0.5mm
>wall thickness and found, when measuring them with a digital caliper,
>that they were no wider between bead-hooks than new ones.
>
>I mention this because, the more spreading of worn rims is mentioned,
>the more it becomes fact among bicyclists. When sidewalls wear too
>thin, they cracks circumferentially at their base and release the
>tire.
>
>Jobst Brandt

Dear Jobst,

How wide were they with a 100+ psi tire inflated on them?

Cheers,

Carl Fogel

 

[David L. Johnson]

daniel wrote:
> Why does my bead keep popping out on my rear veloflex tire? I have
> never had this problem until today when it happened twice in two
> different spots on the rim. I have done nothing to the rear wheel
> recently...

Maybe a bit of the tube was stuck between tire and rim; that is the
usual cause. And, since it did pop off, you did do something to the
rear wheel -- you changed the tube. This can happen twice.

--

David L. Johnson

Arguing with an engineer is like mud wrestling with a pig...
You soon find out the pig likes it!

 

[jim beam]

daniel wrote:
> Why does my bead keep popping out on my rear veloflex tire? I have
> never had this problem until today when it happened twice in two
> different spots on the rim. I have done nothing to the rear wheel
> recently...
>
check the tire beads and compare them to another brand. they should
have a good indent behind the bead where the rim hook goes. if not,
it's defective and you have grounds for return. i've seen this on kenda
tires.

 

[jim beam]

[email protected] wrote:
> On Mar 28, 8:20 pm, jim beam <[email protected]> wrote:
>> daniel wrote:
>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>> never had this problem until today when it happened twice in two
>>> different spots on the rim. I have done nothing to the rear wheel
>>> recently...
>> check the tire beads and compare them to another brand. they should
>> have a good indent behind the bead where the rim hook goes. if not,
>> it's defective and you have grounds for return. i've seen this on kenda
>> tires.
>
> I have already been using the tires and have had no problems.

i didn't ask whether you'd used them, i asked whether you'd checked the
beads for the correct indent for the rim hook. some tire manufacturers
are inattentive to this detail, the bead is insufficiently formed, and
the tire blows off. do you want to figure the problem out, or do you
just want to complain about it?

> Today I
> simply pumped them up as normal and it happened about 12 miles into
> the ride. odd?

if the bead is malformed, not in the least, no.

 

[[email protected]]

On 28 Mar 2007 20:41:08 -0700, [email protected] wrote:

>On Mar 28, 8:20 pm, jim beam <[email protected]> wrote:
>> daniel wrote:
>> > Why does my bead keep popping out on my rear veloflex tire? I have
>> > never had this problem until today when it happened twice in two
>> > different spots on the rim. I have done nothing to the rear wheel
>> > recently...
>>
>> check the tire beads and compare them to another brand. they should
>> have a good indent behind the bead where the rim hook goes. if not,
>> it's defective and you have grounds for return. i've seen this on kenda
>> tires.
>
>I have already been using the tires and have had no problems. Today I
>simply pumped them up as normal and it happened about 12 miles into
>the ride. odd?

Dear Daniel,

Yes, it's odd when tires that used to stay in place start coming off
the rim.

What's your normal inflation?

What model Veloflex is your tire?

http://www.veloflextires.com

Cheers,

Carl Fogel

 

[[email protected]]

Carl Fogel writes:

>>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>>> never had this problem until today when it happened twice in two
>>>> different spots on the rim. I have done nothing to the rear wheel
>>>> recently...

>>> A bad tire?

>>> Higher inflation?

>>> A brake-worn rim slowly spreading?

>> That rims spread is not my experience although they appear to do so
>> because their cheeks wear hollow, so that exterior rim walls slope
>> outward. As I mentioned, I have ridden MA-2 rims to less than
>> 0.5mm wall thickness and found, when measuring them with a digital
>> caliper, that they were no wider between bead-hooks than new ones.

>> I mention this because, the more spreading of worn rims is
>> mentioned, the more it becomes fact among bicyclists. When
>> sidewalls wear too thin, they cracks circumferentially at their
>> base and release the tire.

> How wide were they with a 100+ psi tire inflated on them?

I have no idea, but it couldn't have been much or the rim would have
been permanently bent over such a short distance (about 5mm) of
unsupported rim wall. Why do you ask?

Jobst Brandt

 

[A Muzi]

>> daniel wrote:
>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>> never had this problem until today when it happened twice in two
>>> different spots on the rim. I have done nothing to the rear wheel
>>> recently...

> jim beam <[email protected]> wrote:
>> check the tire beads and compare them to another brand. they should
>> have a good indent behind the bead where the rim hook goes. if not,
>> it's defective and you have grounds for return. i've seen this on kenda
>> tires.

[email protected] wrote:
> I have already been using the tires and have had no problems. Today I
> simply pumped them up as normal and it happened about 12 miles into
> the ride. odd?

A common error is to pull the valve tight before inflating. If you did
that, the base of the valve can catch under the tire edge.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[[email protected]]

On Wed, 28 Mar 2007 22:00:26 -0700, jim beam
<[email protected]> wrote:

>[email protected] wrote:
>> On Mar 28, 8:20 pm, jim beam <[email protected]> wrote:
>>> daniel wrote:
>>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>>> never had this problem until today when it happened twice in two
>>>> different spots on the rim. I have done nothing to the rear wheel
>>>> recently...
>>> check the tire beads and compare them to another brand. they should
>>> have a good indent behind the bead where the rim hook goes. if not,
>>> it's defective and you have grounds for return. i've seen this on kenda
>>> tires.
>>
>> I have already been using the tires and have had no problems.
>
>i didn't ask whether you'd used them, i asked whether you'd checked the
>beads for the correct indent for the rim hook. some tire manufacturers
>are inattentive to this detail, the bead is insufficiently formed, and
>the tire blows off. do you want to figure the problem out, or do you
>just want to complain about it?
>
>> Today I
>> simply pumped them up as normal and it happened about 12 miles into
>> the ride. odd?
>
>if the bead is malformed, not in the least, no.

Dear Jim,

Why snarl?

You're more likely to get cooperation and interesting details with
less attitude.

If the tire is new, then a malformed bead might be the explanation.

But if the tire has been run without problems for a long time (I'm not
sure this is the case, but that's what it sounded like to me), then
what would cause the bead to change shape?

Cheers,

Carl Fogel

 

[[email protected]]

On Thu, 29 Mar 2007 00:16:36 -0600, A Muzi <[email protected]>
wrote:

>>> daniel wrote:
>>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>>> never had this problem until today when it happened twice in two
>>>> different spots on the rim. I have done nothing to the rear wheel
>>>> recently...
>
>> jim beam <[email protected]> wrote:
>>> check the tire beads and compare them to another brand. they should
>>> have a good indent behind the bead where the rim hook goes. if not,
>>> it's defective and you have grounds for return. i've seen this on kenda
>>> tires.
>
>[email protected] wrote:
>> I have already been using the tires and have had no problems. Today I
>> simply pumped them up as normal and it happened about 12 miles into
>> the ride. odd?
>
>A common error is to pull the valve tight before inflating. If you did
>that, the base of the valve can catch under the tire edge.

Dear Andrew,

A good point from an experienced mechanic--it never occurred to me.

But note that "it happened twice in two different spots on the rim."

Maybe this just means on either side of the valve, but it sounds more
like two different places around the rim.

Cheers,

Carl Fogel

 

[[email protected]]

On 29 Mar 2007 05:31:00 GMT, [email protected] wrote:

>Carl Fogel writes:
>
>>>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>>>> never had this problem until today when it happened twice in two
>>>>> different spots on the rim. I have done nothing to the rear wheel
>>>>> recently...
>
>>>> A bad tire?
>
>>>> Higher inflation?
>
>>>> A brake-worn rim slowly spreading?
>
>>> That rims spread is not my experience although they appear to do so
>>> because their cheeks wear hollow, so that exterior rim walls slope
>>> outward. As I mentioned, I have ridden MA-2 rims to less than
>>> 0.5mm wall thickness and found, when measuring them with a digital
>>> caliper, that they were no wider between bead-hooks than new ones.
>
>>> I mention this because, the more spreading of worn rims is
>>> mentioned, the more it becomes fact among bicyclists. When
>>> sidewalls wear too thin, they cracks circumferentially at their
>>> base and release the tire.
>
>> How wide were they with a 100+ psi tire inflated on them?
>
>I have no idea, but it couldn't have been much or the rim would have
>been permanently bent over such a short distance (about 5mm) of
>unsupported rim wall. Why do you ask?
>
>Jobst Brandt

Dear Jobst,

I ask because that may be the question--what happens when the rim is
worn very thin?

A thinner rim will bend out further under the same force from the
inflated tire. How much and whether it's enough to let a tire bead
slip is a tricky question, given different rims, tire beads, and
pressures.

Some time ago, I measured the expansion of a brand-new MA-3 box rim
and two others with 0, 60 and 120 psi inflation:

raw
rim
widths
26" 700x26 700x26
no-box no-box box ma-3
psi steel aluminum aluminum
---- ------ -------- --------
0 1.082" 0.901" 0.085"
60 1.118" 0.907" 0.086"
120 n/a 0/912" 0.088"


total
rim
spread
26" 700x26 700x26
no-box no-box box ma-3
psi steel aluminum aluminum
---- ------ -------- --------
0 x x x
60 0.036" 0.006" 0.001"
120 n/a 0.011" 0.003"

http://groups.google.com/group/rec.bicycles.tech/msg/a5eba5e94f0c6f5d

I don't know how much a badly worn rim would spread, but it seems
reasonable to expect it to spread more than a new rim.

We see lots of post here on RBT about tire-rim combinations that are
either extremely tight or extremely loose, as well as the usual
admonitions about stretchy kevlar beads being suitable only for hooked
rims.

Given normal variations, it then seems reasonable to expect that some
rim-tire combinations may be so marginal that a Veloflex bead (I think
they're all kevlar) will pop out if a rim whose sides have been worn
thin splays out enough at high enough pressures.

Cheers,

Carl Fogel

 

[Donald Gillies]

"daniel" <[email protected]> writes:

>Why does my bead keep popping out on my rear veloflex tire? I have
>never had this problem until today when it happened twice in two
>different spots on the rim. I have done nothing to the rear wheel
>recently...

I had a similar problem with clement ventoux tires on old Rigida 1320
hooked rims. The solution is : don't over-inflate the tire. I had
borrowed a buddy's Silca pump which reached an enormous pressure with
very little effort. That pressure put the tire at risk for blow-off.
I normally use a mountain pump which doesn't attain such pressures and
is self-limiting.

I blew _both_ tires off the rims during our ride - first the rear, and
at the end of the ride - in the heat of the day - the front tire,
too. Both caused immediate blowouts.

- Don Gillies
San Diego, CA

 

[[email protected]]

>>>>i didn't ask whether you'd used them, i asked whether you'd checked the
beads for the correct indent for the rim hook. some tire
manufacturers
are inattentive to this detail, the bead is insufficiently formed,
and
the tire blows off. do you want to figure the problem out, or do you
just want to complain about it? <<<<

I think you are responding to my orginal post twice...I am confused at
your purpose here...

I did check the bead and have been using the tire for a little over a
month...that is why I found it strange that the tire failed after such
use. That is the what I was trying to communicate in both of my
messages...

carl::I usually blow them up to 130 and they are the Pave model with a
max pressure of 140...

 

[jim beam]

[email protected] wrote:
> On Wed, 28 Mar 2007 22:00:26 -0700, jim beam
> <[email protected]> wrote:
>
>> [email protected] wrote:
>>> On Mar 28, 8:20 pm, jim beam <[email protected]> wrote:
>>>> daniel wrote:
>>>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>>>> never had this problem until today when it happened twice in two
>>>>> different spots on the rim. I have done nothing to the rear wheel
>>>>> recently...
>>>> check the tire beads and compare them to another brand. they should
>>>> have a good indent behind the bead where the rim hook goes. if not,
>>>> it's defective and you have grounds for return. i've seen this on kenda
>>>> tires.
>>> I have already been using the tires and have had no problems.
>> i didn't ask whether you'd used them, i asked whether you'd checked the
>> beads for the correct indent for the rim hook. some tire manufacturers
>> are inattentive to this detail, the bead is insufficiently formed, and
>> the tire blows off. do you want to figure the problem out, or do you
>> just want to complain about it?
>>
>>> Today I
>>> simply pumped them up as normal and it happened about 12 miles into
>>> the ride. odd?
>> if the bead is malformed, not in the least, no.
>
> Dear Jim,
>
> Why snarl?
>
> You're more likely to get cooperation and interesting details with
> less attitude.

it's not a snarl. i asked if he'd checked the tire to see if it had a
flaw that would cause his problem. but instead he returned to his start
point - being confounded as to why it would blow off.

need more explanation? /engineers/ think the following joke funny.

***
A pastor, a doctor and an engineer were waiting one morning for a
particularly slow group of golfers.

The engineer fumed, "What's with these guys? We must have been waiting
for 15 minutes!"

The doctor chimed in, "I don't know, but I've never seen such ineptitude!"

The pastor said, "Hey here comes the greenskeeper. Let's have a word
with him."

"Hi George. Say what's with that group ahead of us? They're rather slow
aren't they?"

The greenskeeper replied, "Oh, yes, that's a group of blind
firefighters. They lost their sight saving our clubhouse from a fire
last year, so we always let them play for free anytime."

The group was silent for a moment.

The pastor said, "That's so sad, I think I will say a special prayer for
them tonight."

The doctor said, "Good idea. And I'm going to contact my ophthalmologist
buddy and see if there's anything he can do for them."

The engineer said, "Why can't they play at night?"
***

so, we got the effect part - let's address the cause.


>
> If the tire is new, then a malformed bead might be the explanation.
>
> But if the tire has been run without problems for a long time (I'm not
> sure this is the case, but that's what it sounded like to me), then
> what would cause the bead to change shape?
>
> Cheers,
>
> Carl Fogel

 

[[email protected]]

On 29 Mar 2007 18:06:16 -0700, [email protected] wrote:

[snip]

>I did check the bead and have been using the tire for a little over a
>month...that is why I found it strange that the tire failed after such
>use. That is the what I was trying to communicate in both of my
>messages...
>
>carl::I usually blow them up to 130 and they are the Pave model with a
>max pressure of 140...

Dear Daniel,

When I look at the Veloflex site, the Pave model seems to be listed at
7~8 bar, which is only 101-116 psi:

http://www.veloflextires.com

Elsewhere on that page, Veloflex converts 7~8 bar as 105-120 psi, 4
psi higher than what is strictly accurate.

(Naturally, your Pave model is the only damned clincher model on that
web site without its own specific description. The Pave may be covered
by the "Black" model just below it, with "Pave" and "Black" perhaps
being just gum and black sidewall versions of the the same model.)

For all I know, your actual tire may read "140 psi" on the side--it's
not unknown for web sites to disagree with reality.

But you may have been inflating a 115 psi maximum Kevlar bead tire to
130 psi on a loose-fit rim--you might get away with it for a month or
so, but it would be no surprise if a 115 psi max tire popped off a
loose-fit rim at 130 psi, now and then.

I'd try running the tire at 100 psi, the lower end of the web site
pressure.

Cheers,

Carl Fogel

 

[[email protected]]

Carl::

The tire box and sidewall both say up to 9 bar which I think is around
140 psi...I will try tunning them at a lower pressure over the
weekend...thanks for all the advice!

 

[[email protected]]

On Thu, 29 Mar 2007 19:47:15 -0700, jim beam
<[email protected]> wrote:

>[email protected] wrote:
>> On Wed, 28 Mar 2007 22:00:26 -0700, jim beam
>> <[email protected]> wrote:
>>
>>> [email protected] wrote:
>>>> On Mar 28, 8:20 pm, jim beam <[email protected]> wrote:
>>>>> daniel wrote:
>>>>>> Why does my bead keep popping out on my rear veloflex tire? I have
>>>>>> never had this problem until today when it happened twice in two
>>>>>> different spots on the rim. I have done nothing to the rear wheel
>>>>>> recently...
>>>>> check the tire beads and compare them to another brand. they should
>>>>> have a good indent behind the bead where the rim hook goes. if not,
>>>>> it's defective and you have grounds for return. i've seen this on kenda
>>>>> tires.
>>>> I have already been using the tires and have had no problems.
>>> i didn't ask whether you'd used them, i asked whether you'd checked the
>>> beads for the correct indent for the rim hook. some tire manufacturers
>>> are inattentive to this detail, the bead is insufficiently formed, and
>>> the tire blows off. do you want to figure the problem out, or do you
>>> just want to complain about it?
>>>
>>>> Today I
>>>> simply pumped them up as normal and it happened about 12 miles into
>>>> the ride. odd?
>>> if the bead is malformed, not in the least, no.
>>
>> Dear Jim,
>>
>> Why snarl?
>>
>> You're more likely to get cooperation and interesting details with
>> less attitude.
>
>it's not a snarl. i asked if he'd checked the tire to see if it had a
>flaw that would cause his problem. but instead he returned to his start
>point - being confounded as to why it would blow off.

[snip]

Dear Jim,

Here's what you wrote:

"i didn't ask whether you'd used them, i asked whether you'd checked
the beads for the correct indent for the rim hook. some tire
manufacturers are inattentive to this detail, the bead is
insufficiently formed, and the tire blows off. do you want to figure
the problem out, or do you just want to complain about it?"

Looks like a curt, rude attitude toward a new poster. You wouldn't put
up with it from a doctor, a customer, or a waiter.

Do you want to improve your attitude, or just keep insisting that
everyone else is wrong about it?

Cheers,

Carl Fogel

 

[[email protected]]

On 29 Mar 2007 22:28:56 -0700, [email protected] wrote:

>Carl::
>
>The tire box and sidewall both say up to 9 bar which I think is around
>140 psi...I will try running them at a lower pressure over the
>weekend...thanks for all the advice!

Dear Daniel,

So much for whether web sites agree with the manufacturer prints on
actual tire labels and boxes!

Actually, 9 bar is only 130 psi, not 140 psi. To convert to psi,
multiply bar by 14.5:

bar psi
10 145.0
9 130.5
8 116.0
7 101.5
6 87.0

Cheers,

Carl Fogel