700c ?

In article said:

What's 700 about a 700c wheel? Best guess so far is it's how many Angels
can dance on the end of a spoke but back of envelope calculations suggest
it isn't that either.

"The traditional sizing systems are based on a measurement of the
outside diameter of a tire. This would usually be measured in inches
(26", 27", etc.) or millimeters (650, 700, etc.)."

From http://www.sheldonbrown.com/tire-sizing.html

--
Mike Quin

Mark Thompson said:

What's 700 about a 700c wheel? Best guess so far is it's how many Angels
can dance on the end of a spoke but back of envelope calculations suggest
it isn't that either.

It's an archaic French utility bike tyre 700mm in diameter. The "c"
referred to the width. Modern 700c tyres are about 675mm in diameter,
being so much narrower and hence lower (all bike tyres have roughly a
100% profile, unlike car tyres which start at 80% and go down to about
35% on Porsches).

Mark Thompson said:

What's 700 about a 700c wheel? Best guess so far is it's how many
Angels can dance on the end of a spoke but back of envelope
calculations suggest it isn't that either.

The French inventors just dreamt up the code to confuse us.

Outside tyre diameter varies according to width so that's not it, really.

~PB

Mark Thompson said:

What's 700 about a 700c wheel?

Nothing - it's the outside diameter measured in 25ths of an inch
(that's right, not even real milimetres) of the tyre tread when a
1-3/4" [1] section tyre is fitted.

See http://www.users.globalnet.co.uk/~pattle/nacc/arc0307.htm for the
whole horrible story.

[1] Though to confuse the issue even further, a lot of 700C tyres
carry 28x1-5/8 markings

--
Naqerj