On a lighter note-28 inch tires

[oldpotatoe]

FS post got me thinking, for sale 28 inch Conti tubular plus Vittoria, others all say '28inch' on them. 700c(28 inch) actually smaller than 27 inch plus from metric countries....this along with Euro bearing balls measured in inches....1/4 inch......how come?????

[El Chaba]

I think it pays homage to the bicycle industry's complete disrespect for standards of any kind. After all, there actually was a system of standards for bicycle fittings actually based on the metric system....French threading....While it is all but forgotten today, a few years ago it was held in the same regard as leprosy...Meanwhile in Taiwan, the engineers are busy with yet another bottom bracket "standard"....

[carlineng]

Tire sizing has long baffled me.

29er and 28" are the same, both smaller than 27". Huh?

Why doesn't everyone just use bead seat diameter?? 630, 622, 584, 559. Easy-peezy.

I also find the mixing/matching of measurement systems, often within the same part, pretty amusing. "I have a 100mm, 1" threaded stem, with a 25.4mm clamp size."

[witcombusa]

[QUOTE=carlineng;1533274]
Why doesn't everyone just use bead seat diameter?? 630, 622, 584, 559. Easy-peezy.

QUOTE]




THIS!!!!

[Mark McM]

Why doesn't everyone just use bead seat diameter?? 630, 622, 584, 559. Easy-peezy.

They do - at least for clinchers. Just about every clincher tire made today has the ISO (E.R.T.R.O.) size printed or molded into the sidewall. The ISO size designation includes the tire casing width and bead seat diameter. For example an ISO 23-622 tire has a casing width of 23 mm and a bead seat diameter of 622 mm (this tire is also known as a 700c x 23 in the French tire sizing system).

The fact that tubulars still use an outdated sizing system just reinforces the fact that glueing on tires has been obsoleted.

[Louis]

What's the diameter of your tubular in cubits?

[David Kirk]

I used to work with a guy at Serotta who would ask how long a tube should be and I'd give him an answer like 57..........he'd then ask if that was '57 metric inches or 57 real inches?'.

This was baffling on so many levels.

dave

[carlineng]

Hah! Now I'm tempted to refer to kilograms as "metric pounds" and kilometers as "metric miles"

[oldpotatoe]

They do - at least for clinchers. Just about every clincher tire made today has the ISO (E.R.T.R.O.) size printed or molded into the sidewall. The ISO size designation includes the tire casing width and bead seat diameter. For example an ISO 23-622 tire has a casing width of 23 mm and a bead seat diameter of 622 mm (this tire is also known as a 700c x 23 in the French tire sizing system).

The fact that tubulars still use an outdated sizing system just reinforces the fact that glueing on tires has been obsoleted.

Big 'my aunt Matilda's mustache' on that. Tubular use is more common now than it has been in years. Both because of carbon tube rims
but what a pita tubeless is, compared to it's 'advantages'.

Plus, look at Vittoria clinchers, still say '28 inch' on them.

[Mark McM]

I used to work with a guy at Serotta who would ask how long a tube should be and I'd give him an answer like 57..........he'd then ask if that was '57 metric inches or 57 real inches?'.

This was baffling on so many levels.

dave

Well, there is an official unit of weight called a metric ton (1000 kg = 2204.6 lb), which is about 10% larger than an American ton (2000 lb.) The metric ton is sometimes referred to as tonne, or a 'long ton'.

And if you want to get into other units confusion, there are plenty of other unit names that have different meanings: A mile could be either a statute mile (5280 ft) or a nautical mile (6076 ft); a gallon could be either an imperial gallon (4.546 L) or a US gallon (4.40 L); and ounce can be either a troy ounce (31.10 gm) or an avoirdupois ounce (28.35 gm); etc.

[Mark McM]

Plus, look at Vittoria clinchers, still say '28 inch' on them.

Nope.

Not even their oxymoronically named 'open tubulars.'

http://cdn4.coresites.mpora.com/rcuk/wp-content/uploads/old_images/uploads/images/Huge/10932.jpghttp://www.cyclesuperstore.ie/shop/pc/catalog/large/VIT07.jpg

[Steve in SLO]

Personally, I prefer Imperial pints.

[flydhest]

my father, who retired a few years ago from a 42+ year career at the National Institute for standards and Technology (formerly the National Bureau of Standards) is fond of saying that the US is inching its way to the metric system

[Louis]

It's a good thing we don't have meter-worms in the US - those must be terrifying creatures.

http://visualfunhouse.com/wp-content/uploads/2011/09/zoo-giant-snake-bus-1.jpg

[RedRider]

I used to work with a guy at Serotta who would ask how long a tube should be and I'd give him an answer like 57..........he'd then ask if that was '57 metric inches or 57 real inches?'.

This was baffling on so many levels.

dave

Don't pick on Ben! :no: :)

[Climb01742]

my father, who retired a few years ago from a 42+ year career at the National Institute for standards and Technology (formerly the National Bureau of Standards) is fond of saying that the US is inching its way to the metric system

;)

[oldpotatoe]

Nope.

Not even their oxymoronically named 'open tubulars.'

http://cdn4.coresites.mpora.com/rcuk/wp-content/uploads/old_images/uploads/images/Huge/10932.jpghttp://www.cyclesuperstore.ie/shop/pc/catalog/large/VIT07.jpg

Clinchers are for nancys, nancy.

[witcombusa]

"Clinchers are for nancys, nancy. "


If you'll pardon my reference.....

That ship has sailed, long ago :rolleyes:

[oldpotatoe]

"Clinchers are for nancys, nancy. "


If you'll pardon my reference.....

That ship has sailed, long ago :rolleyes:

Whatever but does anybody know the history of the 28 inch tire reference? Mark, anybody, Ferris?

[witcombusa]

Whatever but does anybody know the history of the 28 inch tire reference? Mark, anybody, Ferris?


Our good friend Sheldon has only this to say in reference to 28" sizing;

"Northern European designation for the 622 mm (700 C) size"

[oldpotatoe]

Our good friend Sheldon has only this to say in reference to 28" sizing;

"Northern European designation for the 622 mm (700 C) size"

Doesn't the UK use feet, inches? I know they use mph...what's 28 inch in 'hands'?

My bike weighs 2 stone, couple of pebbles.

[Mark McM]

Whatever but does anybody know the history of the 28 inch tire reference? Mark, anybody, Ferris?

It comes from the old british tire designation system, whose size is based on the outer diameter of a tire of a standard nominal width. A tire with a nominal width of 1 3/4" on a 622mm (700c) bead diameter rim will have an outer diameter of 28", so this wheel size is called 28".

Likewise, a 1 1/4" nominal width tire on a 630mm rim has an outer diameter of 27", so this wheel size is called 27"

Confusion happens when there are more than one rim size/tire width combinations that have the same outer diameter. For example, a 2" nominal width tire on a 559mm rim (MTB), a 1 3/4" nominal width tire on a 571mm rim (650c) and 1 1/2" nominal width tire on a 584mm rim (650b) all have outer diameters of 26", so all three of these wheel sizes were at one time called 26" wheels.

[oldpotatoe]

It comes from the old british tire designation system, whose size is based on the outer diameter of a tire of a standard nominal width. A tire with a nominal width of 1 3/4" on a 622mm (700c) bead diameter rim will have an outer diameter of 28", so this wheel size is called 28".

Likewise, a 1 1/4" nominal width tire on a 630mm rim has an outer diameter of 27", so this wheel size is called 27"

Confusion happens when there are more than one rim size/tire width combinations that have the same outer diameter. For example, a 2" nominal width tire on a 559mm rim (MTB), a 1 3/4" nominal width tire on a 571mm rim (650c) and 1 1/2" nominal width tire on a 584mm rim (650b) all have outer diameters of 26", so all three of these wheel sizes were at one time called 26" wheels.

Thanks. Those Brits.