Fractional size tires not equivalent to decimal size tires?

I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because the
"20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the size of the
other appears to be 406 mm. That's a big difference.

Does that still hold true?

On 6/20/2016 4:09 PM, John Doe wrote:
I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because the
"20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the size of the
other appears to be 406 mm. That's a big difference.

Does that still hold true?

Yes.

http://www.etrto.org/page.asp?id=1594

On 6/20/2016 6:09 PM, John Doe wrote:
I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because the
"20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the size of the
other appears to be 406 mm. That's a big difference.

Does that still hold true?

Yes.
There is a long history of tire/rim development with myriad
'standards'. The "20" is nominal, roughly the outside
diameter of an inflated tire, which has little to do with
the inside edge if the tire where it meets the bead seat of
the rim.

There are/were various national standards and some
proprietary formats now generally displaced by the ISO
system of expressing the diameter at the seat. Fractions and
decimals denote different series such that a 26x1.375 is
unlike a 26x1-3/8 for example and a 26x1.5 is not at all a
26x1-1/2. There were also letter designations (F10, K2, EA1,
EA3 etc).

If you stay with the ISO numbers, in your example -451,
you'll be fine. A -622 rim for example accepts tires marked
variously 700C and 28" from some suppliers but they are
actually 622 tires.

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

On Monday, June 20, 2016 at 6:09:34 PM UTC-5, John Doe wrote:
I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because the
"20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the size of the
other appears to be 406 mm. That's a big difference.

Does that still hold true?

http://www.sheldonbrown.com/rim-sizing.html
Is a list of all tire size by rim Diameter.

http://www.sheldonbrown.com/tire-sizing.html#width
Is a list of the range of good tire widths for the rim width.

AMuzi wrote:

John Doe wrote:

I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because
the "20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the
size of the other appears to be 406 mm. That's a big difference.

Does that still hold true?

Yes.
There is a long history of tire/rim development with myriad
'standards'. The "20" is nominal, roughly the outside diameter of an
inflated tire, which has little to do with the inside edge if the tire
where it meets the bead seat of the rim.

There are/were various national standards and some proprietary formats
now generally displaced by the ISO system of expressing the diameter
at the seat. Fractions and decimals denote different series such that
a 26x1.375 is unlike a 26x1-3/8 for example and a 26x1.5 is not at all
a 26x1-1/2. There were also letter designations (F10, K2, EA1, EA3
etc).

If you stay with the ISO numbers, in your example -451, you'll be
fine. A -622 rim for example accepts tires marked variously 700C and
28" from some suppliers but they are actually 622 tires.

Can this first one be replaced by the second one?

Kenda K-184, 20 x 1 3/8" (37-440)

Sunlt K-143, 20 X 1-3/8" (37-451)

Assuming the rim is perfect for the first one (37-440).

Thanks.

On 6/21/2016 3:13 PM, John Doe wrote:
AMuzi wrote:

John Doe wrote:

I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because
the "20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the
size of the other appears to be 406 mm. That's a big difference.

Does that still hold true?

Yes.
There is a long history of tire/rim development with myriad
'standards'. The "20" is nominal, roughly the outside diameter of an
inflated tire, which has little to do with the inside edge if the tire
where it meets the bead seat of the rim.

There are/were various national standards and some proprietary formats
now generally displaced by the ISO system of expressing the diameter
at the seat. Fractions and decimals denote different series such that
a 26x1.375 is unlike a 26x1-3/8 for example and a 26x1.5 is not at all
a 26x1-1/2. There were also letter designations (F10, K2, EA1, EA3
etc).

If you stay with the ISO numbers, in your example -451, you'll be
fine. A -622 rim for example accepts tires marked variously 700C and
28" from some suppliers but they are actually 622 tires.

Can this first one be replaced by the second one?

Kenda K-184, 20 x 1 3/8" (37-440)

Sunlt K-143, 20 X 1-3/8" (37-451)

Assuming the rim is perfect for the first one (37-440).


Uh, the ISO -451 is larger diameter than a -440. That's what
the ISO number means.

Neither's better or worse but you can't mount a tire on the
wrong size rim. Either get a -440 rim and a -440 tire OR get
a -451 rim with a -451 tire.

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

On 6/21/2016 1:13 PM, John Doe wrote:
AMuzi wrote:

John Doe wrote:

I read that on Sheldon Brown's website.

A bike that uses 20 x 1 3/8" tires cannot use 20 x 1.5 tires because
the "20" represents different diameters?

The actual relevant size on one appears to be 451 mm while the
size of the other appears to be 406 mm. That's a big difference.

Does that still hold true?

Yes.
There is a long history of tire/rim development with myriad
'standards'. The "20" is nominal, roughly the outside diameter of an
inflated tire, which has little to do with the inside edge if the tire
where it meets the bead seat of the rim.

There are/were various national standards and some proprietary formats
now generally displaced by the ISO system of expressing the diameter
at the seat. Fractions and decimals denote different series such that
a 26x1.375 is unlike a 26x1-3/8 for example and a 26x1.5 is not at all
a 26x1-1/2. There were also letter designations (F10, K2, EA1, EA3
etc).

If you stay with the ISO numbers, in your example -451, you'll be
fine. A -622 rim for example accepts tires marked variously 700C and
28" from some suppliers but they are actually 622 tires.

Can this first one be replaced by the second one?

Kenda K-184, 20 x 1 3/8" (37-440)

Sunlt K-143, 20 X 1-3/8" (37-451)

Assuming the rim is perfect for the first one (37-440).

No.