Very high tyre pressures

In article said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often. Of
course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

If you seriously overinflate the tubes I imagine the tyres could be
forced off the rims.

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

Quoted message said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often.

Of

Quoted message said:

course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

I once destroyed a tyre by overinflating it. The threads under the tread
started to break up and it gave a very rough ride. I do not recommend
overinflating a tyre.

John Dwyer.

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

Quoted message said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often.

Of

Quoted message said:

course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

Possibly an increased chance of a blowout, and more vibration coming through
to your body, hammering your wrists, [censored] and legs. Your frame might not
last as long due to the sharper shocks hitting it. Bicycles are designed for
a particular pressure, and increasing it way beyond that could lead to all
sorts of problems.

Report back in a few weeks if it's still ok!
---
DFM

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

Quoted message said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often.

Of

Quoted message said:

course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

Over inflated tyres tend to crack along the walls but I have never had one
fail on me or at least they wore out before they failed. I don't do it now
but I used to overinflate my 27" by 1 1/8 tyres by a simliar amount to you.
it gave me a better and faster ride (I am about 90kg)
..

Some tyres when constantly overinflated eventually bubble, or a fat
portion appears giving a bumpy ride. You might be lucky though.

Claude said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often. Of
course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

Claude said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often. Of
course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

Hey, just get some tyres rated to the pressure
you want to inflate them too. It's not worth
splitting your wig on the concrete for the
sake of correct inflation. While a catastrophic
failure is probably (?) unlikely, why take the risk ?

-kt

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

Quoted message said:

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

Quoted message said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often.

Of

Quoted message said:

course it makes the ride harder. Does anybody know if there's a serious
downside to this practice (I weigh 100 kgs)?

I once destroyed a tyre by overinflating it. The threads under the tread
started to break up and it gave a very rough ride. I do not recommend
overinflating a tyre.

John Dwyer.

Over inflating your tyres can cause your rims to split. Fairly common
apparently on large volume tyres that are over pressurised.

http://www.sheldonbrown.com/tires.html#pressure

Claude said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often.
Of course it makes the ride harder. Does anybody know if there's a
serious downside to this practice (I weigh 100 kgs)?

I use Continental Super Touring 2000 which are rated at 85 psi max. I
inflate them to anything between 85 and 100. They have done 4000 km
now, and I can see very tiny cracks on the side walls of the rear tyre.
Not sure they are because of the tyre pressure, or just signs of
natural wear and tear. However, I cannot feel the difference in terms
of the ride quality and drag between 85 and 95 psi. Before these, I had
Specialised tyres rated at 100 psi. First I kep them at 80 psi. Not
much comfort anyway, so I decided to pump them up to 100 psi. After
2000 km, I had to replace them under warranty because all thread and
sidwall surfaces were falling apart (got Conti's instead). The conti's
have much better ride quality and lower drag at 85 than the
Specialised's at 100 psi.

By the way, depending on the structure of the tyre, overinflation can
harm rims. I had to replace two spokes with my specialed tyres once I
started to inflate them to 100psi.

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

Quoted message said:

Claude said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75 is
recommended. Means I don't have to pump the bloody things up so often.
Of course it makes the ride harder. Does anybody know if there's a
serious downside to this practice (I weigh 100 kgs)?

I use Continental Super Touring 2000 which are rated at 85 psi max. I
inflate them to anything between 85 and 100. They have done 4000 km
now, and I can see very tiny cracks on the side walls of the rear tyre.
Not sure they are because of the tyre pressure, or just signs of
natural wear and tear. However, I cannot feel the difference in terms
of the ride quality and drag between 85 and 95 psi. Before these, I had
Specialised tyres rated at 100 psi. First I kep them at 80 psi. Not
much comfort anyway, so I decided to pump them up to 100 psi. After
2000 km, I had to replace them under warranty because all thread and
sidwall surfaces were falling apart (got Conti's instead). The conti's
have much better ride quality and lower drag at 85 than the
Specialised's at 100 psi.

By the way, depending on the structure of the tyre, overinflation can
harm rims. I had to replace two spokes with my specialed tyres once I
started to inflate them to 100psi.

That's probably related to the increase in shock that is transfered to the
spokes. I imagine the cracks that are occuring are also cause by an
increased transferral of shock to the rim from the road.

Why did you over-inflated your tires to 95 psi if it makes no difference to
the ride?
---
DFM

Deep Flayed Mar said:

amirm <[email hidden]> wrote in message news:3f4962a2$1-
[email hidden]:[email hidden]...

Quoted message said:

Claude said:

Putting 100 PSI in my hybrid's tyres even though the tyre says 75
is recommended. Means I don't have to pump the bloody things up so
often. Of course it makes the ride harder. Does anybody know if
there's a serious downside to this practice (I weigh 100 kgs)?

I use Continental Super Touring 2000 which are rated at 85 psi max. I
inflate them to anything between 85 and 100. They have done 4000 km
now, and I can see very tiny cracks on the side walls of the rear
tyre. Not sure they are because of the tyre pressure, or just signs of
natural wear and tear. However, I cannot feel the difference in terms
of the ride quality and drag between 85 and 95 psi. Before these, I
had Specialised tyres rated at 100 psi. First I kep them at 80 psi.
Not much comfort anyway, so I decided to pump them up to 100 psi.
After 2000 km, I had to replace them under warranty because all thread
and sidwall surfaces were falling apart (got Conti's instead). The
conti's have much better ride quality and lower drag at 85 than the
Specialised's at 100 psi.

By the way, depending on the structure of the tyre, overinflation can
harm rims. I had to replace two spokes with my specialed tyres once I
started to inflate them to 100psi.

That's probably related to the increase in shock that is transfered to
the spokes. I imagine the cracks that are occuring are also cause by an
increased transferral of shock to the rim from the road.
Why did you over-inflated your tires to 95 psi if it makes no difference
to the ride?
---
DFM

Good point!

Since tyres loose pressure, I try to save on checking/pumping frequency.
At the same time, I wouldn't like to go below 80psi. What I didn't
mention in the previous posting is that although I cannot feel a
tangible difference between 85 and 95 psi, I can feel a noticeable
difference in drag in lower pressures (such as 70 psi vs 85 psi).

So by keeping my tyres a little over-inflated, I remain in the green
zone in-between pumpings. Apparently, ~10 psi above nominated rating is
not having a huge adverse effect on the ride quality (comfort) and
tyre's life.

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Quoted message said:

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