I received my latest copy of "Bicycling" magazine, a periodical published with the sole intent of promoting the emptiness of any bicyclist's bank account. The latest foray into ridiculousness (in my opinion) is the multi-page spread devoted to promoting 27.5 inch wheels on mountain bikes. Hmmmm, just a year ago, the same periodical exclaimed the wonderful virtues of the all new 29 inch wheels on mountain bikes, and how they were faster, surer, more stabile, and an all round wonderful reason to spend $5,000 to $10,000 on a new mountain bike that would be able to handle the increased tire size with a larger frame. Never mind that even six footer's aren't able to touch the ground with both feet while straddling the frame....... Just ride, don't worry about the ground ..... it'll be just fine, you'll see. So now, the 29's are starting to gain acceptance throughout the sport, after much promoting by bicycle frame and component and tire and wheel manufacturers. And now, we are faced with yet another
blitz from all the same people, but especially the media who now proclaims that well, maybe the 29's weren't all that wonderful a replacement to the 26 inch after all, they do have a few weaknesses...... although, we'd never call them by that name. But... a new, hot off the presses wheel size is taking the bike industry by
blitzsturm .... an all new size that promises to do everything the 29 inch can't do, and overcome the weaknesses of the 26 inch sizes...... it's a new .....ready for this...... 27.5 inch tire. It'll climb stronger, descend faster, jump higher, and make
anyone into a superrider... Just switch over to the new tire size, and you'll win every race you enter .....even if you've never raced before. Hmmmmm ..... where have I heard this before? And even if you overlook my attempt of obvious tongue in cheek here, and really start believing the hype put forth by the media, here is a little more to consider .......
After reading all the below article, I think I will secure my fame and fortune by promoting an all new mountain bike tire size, 26 1/4 inch tire, one that will fly higher, jump further, climb faster, descend quicker than the "old fashioned" 26 inch size, and win every race you put it in. Of course, you will have to have an altogether brand new bike with all new suspension, rims, forks, and everything else matched together for this to happen. Of course, I'll be making these new wonderbikes as fast as I can to fill orders, but mind you, this is still a custom operation, and I already have a four year time lag after you order, so the prices will naturally have to reflect this. This new wonderbike will only set you back $12,000, a bargain considering what you can accomplish with it........ If you still want one, after reading below, I'll get started on yours after a bit.......
WHAT DOES TIRE SIZE "700 C"
MEAN?
February 19, 2005
What does the “c”
in 700c stand for? My first guess would be, of course, centimeter, but a wheel
with a diameter of 700 centimeters would be nearly 23 feet across! Thanks.
Chris S.
Chris:
The "C" formerly indicated the width of the tire.
700-size tires come in a variety of widths and "A" once meant the narrowest
while "D" meant the widest. Nowadays, the letters more correctly indicate tire
diameter, for reasons that remain obscure—tho not as obscure as what that "700"
really means. Let me elaborate.
As you’ve obviously seen, bike tires have
printed on their sidewalls a sequence of two sets of characters separated by
"x". The first set, usually a number, tells you the tire’s diameter (measured,
allegedly, at the bead, the circular piece of metal or plastic embedded into the
tire that holds it into the rim). The second set of characters indicates the
tire’s width, sometimes followed by an extra letter at the end to indicate, uh,
the true diameter (I swear I did not make this up).
It turns out
that a 700 C tire actually has a bead diameter of 622 millimeters. So why do
they call it 700? For the same reason a 2-by-4 piece of wood has neither 2 nor 4
as its dimensions; it really measures 1.5 by 3.5 inches, but "2 by 4" rolls off
the tongue better, and probably sells better too. To complicate matters, a tire
labeled 700 B has a diameter of 635 mm and a 700 D tire has a diameter of 587
mm.
This bit of subterfuge doesn’t, however, stop at 700-size tires. It
seems that you can’t trust any of the inch diameters, either: A tire labeled 26"
might actually come in at around 24 ¼ inches (it varies by type of tire, believe
it or not), while a tire that claims 27" might measure roughly 24 ¾
inches.
It gets worse. The second set of characters, the width
measurement, doesn’t cause much trouble if it appears in millimeters, as in 700
x 32 (usually shown as 700 x 32 C, with the C, as I said before, indicating the
true diameter—in this case, 622 mm).
The mischief arises if the width
appears in inches. It sometimes appears as a decimal, as in 26 x 1.75, and
sometimes as a fraction, as in 26 x 1 ¾. You’d think that a 26 x 1.75 tire has
the same size as a 26 x 1 ¾ tire. In reality, the first one has a slightly
larger diameter.
Fortunately, you won’t usually get thrown by this
amusingly chaotic measurement "system" unless you want to replace your bike’s
wheel or install a tire having a different width. In that case, look for another
designation on your existing tire, a designation having two numbers separated by
a hyphen—e.g., 32-622. This designation, established by the trusty European Tyre and Rim Technical
Organisation (ETRTO), tells you, in millimeters, the width followed by the
true diameter. Most new tires come with the ETRTO designation, so when replacing
a tire or wheel you can ignore the "x" designation.
By the way: Some call
the ETRTO designation the ISO (International Standards Organization)
designation. Don’t ask.
Mr Bike
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