Very high tyre pressures

[Claude]

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)?

[Joel Mayes]

In article >, Claude wrote:
> 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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[Joel Mayes]

In article >, Claude wrote:
> 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.

--
| Joel Mayes | Linux and OpenBSD | /"\ ASCII ribbon |
| Accordionist | | \ / campaign against |
| Musician | My PC, My Rules | X HTML mail and |
| Music Teacher | | / \ postings |

[John Dwyer]

"Claude" > wrote in message
...
> 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 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.

[John Dwyer]

"Claude" > wrote in message
...
> 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 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.

[Deep Flayed Mares]

Claude > wrote in message
...
> 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)?

Possibly an increased chance of a blowout, and more vibration coming through
to your body, hammering your wrists, arse 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

[Deep Flayed Mares]

Claude > wrote in message
...
> 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)?

Possibly an increased chance of a blowout, and more vibration coming through
to your body, hammering your wrists, arse 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

[Cody]

"Claude" > wrote in message
...
> 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)?

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)
..

[Cody]

"Claude" > wrote in message
...
> 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)?

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)
..

[Gary K]

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

Claude > wrote:

> 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)?

[Gary K]

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

Claude > wrote:

> 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)?

[kingsley]

On Sat, 23 Aug 2003 05:41:46 +0000, Claude wrote:

> 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

[kingsley]

On Sat, 23 Aug 2003 05:41:46 +0000, Claude wrote:

> 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

[Marty]

"John Dwyer" > wrote in message >...
> "Claude" > wrote in message
> ...
> > 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 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.

[Marty]

"John Dwyer" > wrote in message >...
> "Claude" > wrote in message
> ...
> > 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 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.

[stu]

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

[stu]

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

[amirm]

Claude wrote:
> 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]

Claude wrote:
> 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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[Deep Flayed Mares]

amirm > wrote in message
...
> Claude wrote:
> > 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 Mares]

amirm > wrote in message
...
> Claude wrote:
> > 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

[amirm]

Deep Flayed Mar wrote:
> amirm > wrote in message news:3f4962a2$1-
> ot.net.au...
> > Claude wrote:
> > > 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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[amirm]

Deep Flayed Mar wrote:
> amirm > wrote in message news:3f4962a2$1-
> ot.net.au...
> > Claude wrote:
> > > 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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