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Tire Sizing(10 posts)

Tire Sizingdaniell
Apr 11, 2003 6:07 AM
I just replaced my Specialized 700 X 23 tire. I had an old unused tire laying around. It is a Michelin Select 700 X 25. The Michelin is much narrower than the Specialized. Too narrow for me. I want to buy new tires. Can someone recommend a brand of tire that is on the wide side. Are the 25s really wider than the 23s?

You'd think that 25mm would mean 25mm.Spoke Wrench
Apr 11, 2003 7:10 AM
But it ain't that way with bicycle tires. Within the same brand and model of tire, I think that it's pretty safe to say that a 25 will be wider than a 23. When you start mixing brands and models, that isn't necessarily true. One brand's 23mm might actually be wider than someone else's 25mm.

I've read posts from guys who have painstakingly mounted and inflated various tires and carefully measured the widths. That's too much trouble for me. I can't tell you what brands run wide and what's narrow.
even within manufacturers, it can varyjw25
Apr 11, 2003 9:00 AM
For instance, a 23mm Vittoria Open Corsa CX is wider and taller than a 23mm Vittoria Techno Pro.
In general, a lot of manufacturers list tire sizes bigger than reality, because it makes the weight seem lower. Sadly, this leads to a lot of confusion.
What model SPecialized tire? I always thought the older ones were skinny. I once rode some Turbo/R's that said 23mm, but were maybe 20's if you were being generous.
Personally, I've got a pair of Michelin Axial Pro 25's, and they're fat - almost too fat for my frame. Very comfy, though, and not too heavy. I'll be racing them on rough courses this year. I haven't used the Selects, though, so I can't say how the width compares.
If you really want bigger tires, something like the Rivendell Rolly-Polly or Ruffy-Tuffy might suit you. They're 27-28mm wide, made by Panaracer, and highly regarded.
Other than that, head to a bike shop and look around. If a tire's rolled flat, you can compare widths pretty easily. If they're wire-beaded, it's a little harder, but by holding the beads roughly a finger's width apart, and squeezing the tread open, you can get a rough idea of width.
even within manufacturers, it can varydaniell
Apr 11, 2003 9:28 AM
The previous tire was a Specialize Armadillo.
re: Tire Sizingbrider
Apr 11, 2003 9:42 AM
Regardless of the label, there's a number molded into the casing that should be a true size. For 700 tires the number should be 622-XX. 622 is the bead seat diameter in mm, and the XX is the casing width, mounted on a standard (whatever that is) rim. Use these numbers for comparison rather than a label.
No, No, No!!!Alexx
Apr 11, 2003 1:22 PM
The xx is the PROFILE HEIGHT, not the width. Check what the ERTRO number means-you use the profile height # to determine actual diameter of the wheel.

Only ATB tires, with their 26" x 1.yy" size refer to width.

The fact that the xx is usually close to the actual width is coincidental.
I stand corrected. (nm)brider
Apr 11, 2003 2:05 PM
Isn't that what you really want anyway?Matno
Apr 12, 2003 5:59 AM
Seems like profile height is more directly related to comfort than the width. At least, that's been my experience with MTB tires. (i.e. I haven't noticed much difference in cushion with wider tires, but I have noticed it with taller tires). Maybe it's just me. Regardless of whether height or width is increased, it seems like the total volume change would make the most difference...
Good pointAlexx
Apr 13, 2003 9:13 AM
But, it's really good for those people who need to know EXACTLY what the diameter of the wheel is (god forbid if the computer is off by 2%!!).

Still it's amazing how that every 10 days or so, some caliper-weilding cyclist posts just such a message, and 5 or 6 know-nothings return with the old "manufacturers lie about the width" excuse. You'd think that, by now, everybody here would know that it isn't the width measurement? Guess not...

Yes, some manufacturers are a bit off on their dimensions, but if people used their verniers to measure the profile height, I'd bet that you wouldn't find so much variability!
Have you ever looked at women's clothes sizes?Kerry
Apr 11, 2003 4:29 PM
My wife fits size 8, 9, 10, and 12. Somehow, she doesn't change shape, but the clothes do. Bike tire sizing seems like it should be extremely straightforward, but somehow manufacturers can't be bothered to mount the tires on rims, pump them up, and measure them!