tire pressure

Quoted message said:

There was / is a formula around that used the reduction in sidewall
height as an indication of pressure, ie: the tire deforms, by a
certain amount when the rider is mounted.

I think the factor was 10% of the casing height. Anyone know what I am
talking about and where I can get a copy of it?

Appreciated

The "ideal" was a ~15% "drop" in casing height. This table gives
approximate inflation for a 15% drop v. rider + bike weight for
various tire widths:

http://preview.tinyurl.com/yukgw3

or

http://tinyurl.com/yukgw3

Ozark Bicycle said:

Quoted message said:

There was / is a formula around that used the reduction in sidewall
height as an indication of pressure, ie: the tire deforms, by a
certain amount when the rider is mounted.

I think the factor was 10% of the casing height. Anyone know what I am
talking about and where I can get a copy of it?

Appreciated

The "ideal" was a ~15% "drop" in casing height. This table gives
approximate inflation for a 15% drop v. rider + bike weight for
various tire widths:

http://preview.tinyurl.com/yukgw3

or

http://tinyurl.com/yukgw3

That table only goes up to 154 lbs. Is there one for adults somewhere?.....
~

DougC said:

Ozark Bicycle said:

Quoted message said:

There was / is a formula around that used the reduction in sidewall
height as an indication of pressure, ie: the tire deforms, by a
certain amount when the rider is mounted.

Quoted message said:

Quoted message said:

I think the factor was 10% of the casing height. Anyone know what I am
talking about and where I can get a copy of it?

Quoted message said:

Quoted message said:

Appreciated

Quoted message said:

The "ideal" was a ~15% "drop" in casing height. This table gives
approximate inflation for a 15% drop v. rider + bike weight for
various tire widths:

Quoted message said:

http://preview.tinyurl.com/yukgw3

Quoted message said:

or

Quoted message said:

http://tinyurl.com/yukgw3

That table only goes up to 154 lbs. Is there one for adults somewhere?.....

It's *per wheel", assuming a 45/55% split front v. rear.

If you need higher than that, you need a pretty special set of wheels.

Ozark Bicycle said:

Quoted message said:

There was / is a formula around that used the reduction in sidewall
height as an indication of pressure, ie: the tire deforms, by a
certain amount when the rider is mounted.

Quoted message said:

I think the factor was 10% of the casing height. Anyone know what I am
talking about and where I can get a copy of it?

Quoted message said:

Appreciated

The "ideal" was a ~15% "drop" in casing height. This table gives
approximate inflation for a 15% drop v. rider + bike weight for
various tire widths:

http://preview.tinyurl.com/yukgw3

or

http://tinyurl.com/yukgw3

What does that ideal 15% represent - the amount of drop in casing
height that will be ideal for riding on? Should we interepret the
chart as indicating the ideal tire pressure for our weight (on the
tire)?
Thanks.

Camilo said:

On Jul 31, 2:56 am, Ozark Bicycle

Quoted message said:

On Jul 31, 4:38 am, [email hidden] wrote:

Quoted message said:

Quoted message said:

There was / is a formula around that used the reduction in sidewall
height as an indication of pressure, ie: the tire deforms, by a
certain amount when the rider is mounted.

Quoted message said:

Quoted message said:

I think the factor was 10% of the casing height. Anyone know what I am
talking about and where I can get a copy of it?

Quoted message said:

Quoted message said:

Appreciated

Quoted message said:

The "ideal" was a ~15% "drop" in casing height. This table gives
approximate inflation for a 15% drop v. rider + bike weight for
various tire widths:

Quoted message said:

http://preview.tinyurl.com/yukgw3

Quoted message said:

or

Quoted message said:

http://tinyurl.com/yukgw3

What does that ideal 15% represent - the amount of drop in casing
height that will be ideal for riding on?

According to some bicycle tire manufactuer(s), yes, IIRC. IOW, a tire
with an unloaded height of 35mm would "drop" to a height of ~29mm,
with an attendant gain in width at the contact patch.

Quoted message said:

Should we interepret the
chart as indicating the ideal tire pressure for our weight (on the
tire)?

The table provides data for the load *per wheel*, assuming a 45/55%
split front v. rear. IOW, a 200lb rider + bike will put 110lbs on the
rear wheel and 90 lbs on the front wheel.

Quoted message said:

Thanks.- Hide quoted text -

- Show quoted text -

Ozark Bicycle said:

Quoted message said:

There was / is a formula around that used the reduction in sidewall
height as an indication of pressure, ie: the tire deforms, by a
certain amount when the rider is mounted.

I think the factor was 10% of the casing height. Anyone know what I am
talking about and where I can get a copy of it?

Appreciated

The "ideal" was a ~15% "drop" in casing height. This table gives
approximate inflation for a 15% drop v. rider + bike weight for
various tire widths:

http://preview.tinyurl.com/yukgw3

or

http://tinyurl.com/yukgw3

Great chart! I'd be curious to see just how far off the 15% drop one gets
for being under/over inflated. According to the chart, my heavy body on my
heavy bike leads to 112/130psi for my 700x23c tires. Normally I've been
riding with them at about 106psi both front and back. How much am I
overcompressing them I wonder.

Colin