Proper Tire Inflation

I've read a bit on this on Sheldon Brown's site, however, I'm looking for a
more precise answer, if possible.

My road bike tires say that max inflation is 130 psi. Okay, before my last
25 mile ride, I inflated my front tire to 130 psi, since I wanted to roll
easy. So I do the ride okay, get the home & put the bike up w/ no problems.
Next time I go for it, the front tire is flat. Get the tube off to find it
split several inches along the inside seem, so it appears to me that this
was due to over inflation. Was it? And if so, could I have avoided this by
inflating to 125 psi, instead of 130 psi? It was a clear & sunny day, so
there was no need to have less air in the tire. How close to max can one
go, in general? Maybe a had a slightly bumb tube?

Thanks.

On Mon, 8 Dec 2003 15:00:18 -0500, "Roger Zoul"
wrote:

I've read a bit on this on Sheldon Brown's site, however, I'm looking for a
more precise answer, if possible.

My road bike tires say that max inflation is 130 psi. Okay, before my last
25 mile ride, I inflated my front tire to 130 psi, since I wanted to roll
easy. So I do the ride okay, get the home & put the bike up w/ no problems.
Next time I go for it, the front tire is flat. Get the tube off to find it
split several inches along the inside seem, so it appears to me that this
was due to over inflation. Was it? And if so, could I have avoided this by
inflating to 125 psi, instead of 130 psi? It was a clear & sunny day, so
there was no need to have less air in the tire. How close to max can one
go, in general? Maybe a had a slightly bumb tube?

Your answer is in your own text. The tire's max inflation is 130, and
it survived the 130psi just fine. The tube, however did not fare so
well. Sounds like you had a bad tube. It is interesting though that
you say it was "split several inches along the inside seem". Is that a
several inch long split, or in several inches from the valve, or
something else? A several inch split would tell me it blew while
inside - after the ride. Otherwise, you would have been riding on the
rim.

Dan Brussee wrote:
:: On Mon, 8 Dec 2003 15:00:18 -0500, "Roger Zoul"
:: wrote:
::
::: I've read a bit on this on Sheldon Brown's site, however, I'm
::: looking for a more precise answer, if possible.
:::
::: My road bike tires say that max inflation is 130 psi. Okay, before
::: my last 25 mile ride, I inflated my front tire to 130 psi, since I
::: wanted to roll easy. So I do the ride okay, get the home & put the
::: bike up w/ no problems. Next time I go for it, the front tire is
::: flat. Get the tube off to find it split several inches along the
::: inside seem, so it appears to me that this was due to over
::: inflation. Was it? And if so, could I have avoided this by
::: inflating to 125 psi, instead of 130 psi? It was a clear & sunny
::: day, so there was no need to have less air in the tire. How close
::: to max can one go, in general? Maybe a had a slightly bumb tube?
::
:: Your answer is in your own text. The tire's max inflation is 130, and
:: it survived the 130psi just fine. The tube, however did not fare so
:: well. Sounds like you had a bad tube. It is interesting though that
:: you say it was "split several inches along the inside seem". Is that
:: a several inch long split, or in several inches from the valve, or
:: something else? A several inch split would tell me it blew while
:: inside - after the ride. Otherwise, you would have been riding on the
:: rim.

Thanks. The tube had a split along the inside seem that was several inches
long. I would not expect a puncture to produce a split like that, on the
inner radius of the tube. Also, I don't think I was riding on the rim --
that I have learned to notice

"Roger Zoul" wrote in message
...
I've read a bit on this on Sheldon Brown's site, however, I'm looking for
a
more precise answer, if possible.

My road bike tires say that max inflation is 130 psi. Okay, before my
last
25 mile ride, I inflated my front tire to 130 psi, since I wanted to roll
easy. So I do the ride okay, get the home & put the bike up w/ no
problems.
Next time I go for it, the front tire is flat. Get the tube off to find
it
split several inches along the inside seem, so it appears to me that this
was due to over inflation. Was it? And if so, could I have avoided this by
inflating to 125 psi, instead of 130 psi? It was a clear & sunny day, so
there was no need to have less air in the tire. How close to max can one
go, in general? Maybe a had a slightly bumb tube?

Thanks.


It's quite common for people to pump their tires right to the max psi or
even slightly beyond. I don't recommend going beyond, but I know it's
pretty commonly done by folks like triathletes and that who believe they're
reducing rolling resistance.

Sounds to me like you had a bumb tube, but I'd make sure your rim tape is
covering all the spoke holes on the rim and that there aren't any exposed
edges that could create a hole.

One last thing. High psi isn't good for all wheels. Some of the fancy,
low-spoke count, light weight wheels can develop cracks at the spoke holes
if you keep the tire pressure too high.

Bob C.

Roger Zoul writes:

I've read a bit on this on Sheldon Brown's site, however, I'm
looking for a more precise answer, if possible.

My road bike tires say that max inflation is 130 psi. Okay, before
my last 25 mile ride, I inflated my front tire to 130 psi, since I
wanted to roll easy. So I do the ride okay, get the home & put the
bike up w/ no problems. Next time I go for it, the front tire is
flat. Get the tube off to find it split several inches along the
inside seem, so it appears to me that this was due to over
inflation. Was it? And if so, could I have avoided this by
inflating to 125 psi, instead of 130 psi? It was a clear & sunny
day, so there was no need to have less air in the tire. How close
to max can one go, in general? Maybe a had a slightly bum tube?

Tubes cannot split open in the tire from high pressure. Your tire
blew off the rim while you weren't there or you would have heard it.
You should probably run tires at 120psi or less, and don't expect to
descend steep braking hills at that pressure either.

http://draco.acs.uci.edu/rbfaq/FAQ/8b.4.html

This is not new.

Jobst Brandt

In article , says...

"Roger Zoul" wrote in message
...
I've read a bit on this on Sheldon Brown's site, however, I'm looking for
a
more precise answer, if possible.

My road bike tires say that max inflation is 130 psi. Okay, before my
last
25 mile ride, I inflated my front tire to 130 psi, since I wanted to roll
easy. So I do the ride okay, get the home & put the bike up w/ no
problems.
Next time I go for it, the front tire is flat. Get the tube off to find
it
split several inches along the inside seem, so it appears to me that this
was due to over inflation. Was it? And if so, could I have avoided this by
inflating to 125 psi, instead of 130 psi? It was a clear & sunny day, so
there was no need to have less air in the tire. How close to max can one
go, in general? Maybe a had a slightly bumb tube?

Thanks.


It's quite common for people to pump their tires right to the max psi or
even slightly beyond. I don't recommend going beyond, but I know it's
pretty commonly done by folks like triathletes and that who believe they're
reducing rolling resistance.

Sounds to me like you had a bumb tube, but I'd make sure your rim tape is
covering all the spoke holes on the rim and that there aren't any exposed
edges that could create a hole.

One last thing. High psi isn't good for all wheels. Some of the fancy,
low-spoke count, light weight wheels can develop cracks at the spoke holes
if you keep the tire pressure too high.

How does that happen? I can see cracking from too-high spoke tension,
but not from too-high tire pressure.

--
Dave Kerber
Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

One last thing. High psi isn't good for all wheels. Some of the fancy,
low-spoke count, light weight wheels can develop cracks at the spoke holes
if you keep the tire pressure too high.

How does that happen? I can see cracking from too-high spoke tension,
but not from too-high tire pressure.

Mavic has a maximum recommended air pressure for their wheel/rims. It's
buried somewhere on their website and lower than you might think.


Chris Neary


"Science, freedom, beauty, adventu what more could
you ask of life? Bicycling combined all the elements I
loved" - Adapted from a quotation by Charles Lindbergh

psycholist wrote:
:: "Roger Zoul" wrote in message
:: ...
::: I've read a bit on this on Sheldon Brown's site, however, I'm
::: looking for a more precise answer, if possible.
:::
::: My road bike tires say that max inflation is 130 psi. Okay, before
::: my last 25 mile ride, I inflated my front tire to 130 psi, since I
::: wanted to roll easy. So I do the ride okay, get the home & put the
::: bike up w/ no problems. Next time I go for it, the front tire is
::: flat. Get the tube off to find it split several inches along the
::: inside seem, so it appears to me that this was due to over
::: inflation. Was it? And if so, could I have avoided this by
::: inflating to 125 psi, instead of 130 psi? It was a clear & sunny
::: day, so there was no need to have less air in the tire. How close
::: to max can one go, in general? Maybe a had a slightly bumb tube?
:::
::: Thanks.
:::
::
:: It's quite common for people to pump their tires right to the max
:: psi or even slightly beyond. I don't recommend going beyond, but I
:: know it's pretty commonly done by folks like triathletes and that
:: who believe they're reducing rolling resistance.
::
:: Sounds to me like you had a bumb tube, but I'd make sure your rim
:: tape is covering all the spoke holes on the rim and that there
:: aren't any exposed edges that could create a hole.

I did check the rim tape covering the spoke holes...all seems fine there.

::
:: One last thing. High psi isn't good for all wheels. Some of the
:: fancy, low-spoke count, light weight wheels can develop cracks at
:: the spoke holes if you keep the tire pressure too high.

Mine are by Specialized...those are low-spoke count wheels, too. However,
the tires are 700 x 26, so those aren't as lightweight as others, I'd think.

wrote:
:: Roger Zoul writes:
::
::: I've read a bit on this on Sheldon Brown's site, however, I'm
::: looking for a more precise answer, if possible.
::
::: My road bike tires say that max inflation is 130 psi. Okay, before
::: my last 25 mile ride, I inflated my front tire to 130 psi, since I
::: wanted to roll easy. So I do the ride okay, get the home & put the
::: bike up w/ no problems. Next time I go for it, the front tire is
::: flat. Get the tube off to find it split several inches along the
::: inside seem, so it appears to me that this was due to over
::: inflation. Was it? And if so, could I have avoided this by
::: inflating to 125 psi, instead of 130 psi? It was a clear & sunny
::: day, so there was no need to have less air in the tire. How close
::: to max can one go, in general? Maybe a had a slightly bum tube?
::
:: Tubes cannot split open in the tire from high pressure. Your tire
:: blew off the rim while you weren't there or you would have heard it.
:: You should probably run tires at 120psi or less, and don't expect to
:: descend steep braking hills at that pressure either.

You know....when I first went to get the bike and noticed the flat, the tire
was off the rim! I remember wondering how it could have come off like that,
rather than just going flat. BTW, on the day of my ride it was extremely
windy, and I'm a heavy guy. Maybe there was some rim heating.
::
:: http://draco.acs.uci.edu/rbfaq/FAQ/8b.4.html
::
:: This is not new.

I see. Thanks.

In article ,
says...
One last thing. High psi isn't good for all wheels. Some of the fancy,
low-spoke count, light weight wheels can develop cracks at the spoke holes
if you keep the tire pressure too high.

How does that happen? I can see cracking from too-high spoke tension,
but not from too-high tire pressure.

Mavic has a maximum recommended air pressure for their wheel/rims. It's
buried somewhere on their website and lower than you might think.

I understand why a rim might have a limit on pressure (at least for
clinchers), but this would seem to be a bead/rim sidewall issue, not a
spoke hole issue.

--
Dave Kerber
Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.