Tubular tires and pressure

Hi.

Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest advantage of tubulars was that you could run them at LOW pressures without risking pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire used inside on avelodrome track? DO people actually run tubulars on the rad at 200 PSI? Wouldn't that make for a rather jarring ride?

Cheers

On Monday, December 30, 2013 9:30:40 PM UTC-6, Sir Ridesalot wrote:
Hi.
Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest advantage of tubulars was that you could run them at LOW pressures without risking pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire used inside on avelodrome track? DO people actually run tubulars on the rad at 200 PSI? Wouldn't that make for a rather jarring ride?


200 psi is for the crazy people who do not know how bicycle tires work. 115psi is also high for tubular tires. A velodrome might be OK for 115psi. When I used tubulars I inflated to 100psi front and rear. I do that for my clinchers too. I've never had the mythical pinch flat.

Sir Ridesalot wrote:
Hi.

Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is
recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest advantage
of tubulars was that you could run them at LOW pressures without risking pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire
used inside on avelodrome track? DO people actually run tubulars on the
rad at 200 PSI? Wouldn't that make for a rather jarring ride?

Cheers

I think it depends on your weight and the width of the tire. But this is a
good link:
http://sheldonbrown.com/tires.html
--
duane

On Monday, December 30, 2013 10:30:40 PM UTC-5, Sir Ridesalot wrote:
Hi.



Finally got myself a new tubular tire.



I noticed that the air pressure can be as high as 200 PSI and low is recommended to be 115 PSI.



At the risk of starting a tire war, I thought that the biggest advantage of tubulars was that you could run them at LOW pressures without risking pinch flats.



200 PSI seems pretty high to me. OWuld that pressure be more for a tire used inside on avelodrome track? DO people actually run tubulars on the rad at 200 PSI? Wouldn't that make for a rather jarring ride?



Cheers

What's the brand and model of the tire?

- Frank Krygowski

On Mon, 30 Dec 2013 19:30:40 -0800, Sir Ridesalot wrote:

Hi.

Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is
recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest advantage
of tubulars was that you could run them at LOW pressures without risking
pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire
used inside on avelodrome track? DO people actually run tubulars on the
rad at 200 PSI? Wouldn't that make for a rather jarring ride?

Cheers

Tubulars have a lot of advantages besides being able to run at low
pressures.

A big caution is to let the air out after you have finished riding the
bike for the day. Even at 115 psi, you are pulling the stitching apart.
You want to reserve those stresses to when you are actually riding.

I'd pump the tire up to 120 psi, back when I was around 150 lbs. At that
pressure a clean puncture or blowout sounds like a gun shot. I was once
riding down Lexington Ave in NYC around noon. I got a puncture just as I
was crossing 42nd St (corner of Grand Central Terminal). I cleared the
streets of pedestrians. They were all running for cover.

Stephen Bauman

On 12/30/2013 9:30 PM, Sir Ridesalot wrote:
Hi.

Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest advantage of tubulars was that you could run them at LOW pressures without risking pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire used inside on avelodrome track? DO people actually run tubulars on the rad at 200 PSI? Wouldn't that make for a rather jarring ride?

Cheers


The difference between a maximum casing burst pressure of
200psi and any reasonably efficient and comfortable riding
pressure (something just past 100psi) may well be not only a
wide gulf but a case of apples and oranges.

Note Jan Heinie's data indicating a J-curve for rolling
resistance which optimizes around (IIRC?) 115psi.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 12/31/2013 7:58 AM, Stephen Bauman wrote:
On Mon, 30 Dec 2013 19:30:40 -0800, Sir Ridesalot wrote:

Hi.

Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is
recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest advantage
of tubulars was that you could run them at LOW pressures without risking
pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire
used inside on avelodrome track? DO people actually run tubulars on the
rad at 200 PSI? Wouldn't that make for a rather jarring ride?

Cheers

Tubulars have a lot of advantages besides being able to run at low
pressures.

A big caution is to let the air out after you have finished riding the
bike for the day. Even at 115 psi, you are pulling the stitching apart.
You want to reserve those stresses to when you are actually riding.

I'd pump the tire up to 120 psi, back when I was around 150 lbs. At that
pressure a clean puncture or blowout sounds like a gun shot. I was once
riding down Lexington Ave in NYC around noon. I got a puncture just as I
was crossing 42nd St (corner of Grand Central Terminal). I cleared the
streets of pedestrians. They were all running for cover.

Stephen Bauman



I'm not so sure about that.

My too nice for daily use bike has handmade tires with latex
tubes which bleed down overnight to make that irrelevant
despite very fine casing and extremely uniform section.

Yet my daily riding bikes with butyl tubulars get aired only
every couple of weeks and show no signs of harm until the
inevitable catastrophic road debris encounter.

So, although oft-repeated and sorta plausible, the effect
doesn't seem to show up in the real world.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Tue, 31 Dec 2013 08:38:26 -0600, AMuzi wrote:

On 12/30/2013 9:30 PM, Sir Ridesalot wrote:
Hi.

Finally got myself a new tubular tire.

I noticed that the air pressure can be as high as 200 PSI and low is
recommended to be 115 PSI.

At the risk of starting a tire war, I thought that the biggest
advantage of tubulars was that you could run them at LOW pressures
without risking pinch flats.

200 PSI seems pretty high to me. OWuld that pressure be more for a tire
used inside on avelodrome track? DO people actually run tubulars on the
rad at 200 PSI? Wouldn't that make for a rather jarring ride?

Cheers


The difference between a maximum casing burst pressure of 200psi and any
reasonably efficient and comfortable riding pressure (something just
past 100psi) may well be not only a wide gulf but a case of apples and
oranges.

Note Jan Heinie's data indicating a J-curve for rolling resistance which
optimizes around (IIRC?) 115psi.

One oft stated reason for inflating tubulars to more than the optimum
pressure is resistance to flats. The theory is that the harder tire would
be more likely to crush glass than have the glass chard cause a flat.

This may be another urban legend. I cannot claim that strategy was 100%
effective. I got more than my share of flats despite pumping up tires
each morning.

Stephen Bauman