Cyclocross - Actual size of 700x30 tires

Are the outermost points of the nubs at the 30 measurement, or are they in addition to it?
I'm trying to figure out if I can run some skinny & fast CX tires for winter use on my road frame.

I think you're looking for a level of precision that the industry doesn't provide. I've found considerable variation in different tire brands/models that were all nominally the same width. And a given tire will also have some variation in width depending on the width of the rim

If you are talking about Michelin tires, they measure more like 32 than the listed size of 30

You must measure them on your rims, at your normal operating pressure, on your bike.

Thanks for the responses..
Perhaps if I take a picture with my 700x25 road tires, someone would be able to make a slightly more educated guess than me as to whether or not it'll work?

Just trying to figure it out before I make the purchase commitment.

The actual measured size will also depend on the rims that the tires are mounted on. For example, I had some 700x32 ritchey speedmaxes mounted on a wide rim that measured just as wide as some 700x35 speedmaxes mounted on narrower rims.

They are velocity deep v's, which the site claims as 19mm wide, though that may be an external rather than internal dimension.

If you are talking about Michelin tires, they measure more like 32 than the listed size of 30

I think this depends on the tire pressure and rim width . My Mich Mud2's measure right at 30mm (at the sidewalls,the knobs don't protrude) at around 35 PSI on an Alex AT-450 rim. I haven't checked them higher than that, but I have noticed with other tires the higher pressure makes them bulge more.

They are velocity deep v's, which the site claims as 19mm wide, though that may be an external rather than internal dimension.

I would guess it is an external measurement. The rim I mention above with 30mm Mud2's is 18.5mm on the outside, so you might be OK there.

The question I would have is what you are trying to accomplish with these tires. Riding on snow? wet roads? ice?

With regard to the Michelin Mud2's, I can tell you they are very good on grass, light gravel, mud and wet pavement. I was particularly surprised how well they grip on wet pavement. I was taking 90 degree turns at around 17 mph with no slipping this weekend without a hint of slipping. They'd probably be OK on snow, though ideally with dirt underneath it rather than pavement. I doubt they'd help much with ice.

The downside is that they have no flat protection (other than the knobs), and the knobs will wear quickly on pavement (not to mention slowing you down).

My Schwalbe Marathon Supremes measure 35mm, on 18mm wide riims (internal).

Almost all, different manufacturers, different models, tires measure differently, even on the same rims.

The best you can do is measure the available space on each side of the existing tire, and along the tread, wherever the tire will come into contact with your frame. Don't forget the brake bridge, and the bridge down by the pedals, in addition to all fork measurements. Factor in the width of the existing tire, and you should have your answer as to available space. Then figure tires could measure as much as 5mm different than they are marked.

Well, the purpose of these tires is that I've completely worn out the current ones, and thought that some CX tires might be pertinent for the winter. Winters around here are snowy and wet, and the roads have a bit of sand, and they also get beaten up pretty badly by the plows.
That said, the tires will still mainly be used on the pavement. I don't mind if it slows me down a little bit, it's a commuter bike more than a fast road bike, and I'll be gearing it down slightly for the winter.
If anyone has some narrower suggestions with a faster-rolling center section, I'm all ears.
I'll take some measurements this evening, and see if I've got around 5mm on each side & 10 on the top, that should make for a 35 tire fitting & if I get a 30, there should be spare space!

Had a bit of a d'oh moment when I went out to measure more.
There's a bike in the garage with 700x35 nominal tires! One of those comfort-cross type bikes. My Mom's
From the measuring, the front is going to be a closer fit than the rear, so I didn't try the rear on (yet, at least. I might before actually purchasing, if you guys think this looks OK in the front)
Here are the photos-
http://i220.photobucket.com/albums/dd8/xxguitarist/1258686508.jpg
http://i220.photobucket.com/albums/dd8/xxguitarist/1258686507.jpg
And rim details
http://i220.photobucket.com/albums/dd8/xxguitarist/1258686509.jpg http://i220.photobucket.com/albums/dd8/xxguitarist/1258686510.jpg

Are the wider rims likely to make the tires actually shorter? These rims are much wider than my current ones, and the clearance on the top is rather tight as is!
Think the 700x30 would fit, given the fitment of these 700x35?

Given my intended use, should I perhaps be considering "city/touring" tires instead?

Given my intended use, should I perhaps be considering "city/touring" tires instead?

I would. If you don't mind the weight something like the Schwalbe Marathon or Marathon Plus would be perfect.

I had looked at the marathon plus. Happen to have a better source than biketiresdirect? PBK doesn't seem to stock it.

I was also looking at the conti contact and conti city ride, as both are cheaper and generally similar tire types. Both of those two would be in 700x32.

I like Bike Tires Direct because they happen to be local to me. If you've got a decent LBS, that might be worth paying a few extra bucks because you could probably make an exchange if you weren't happy with the fit.

Otherwise, it looks like Bike Tires Direct is about as good as you're going to find. Did you see that you get a discount for buying two?

Andy,
I did notice that- always a happy surprise when they give you a discount for multiples.
Any idea of relative quality of the tires I mentioned?
The nice thing about the schwalbes is the higher psi rating.. but the others are cheaper & these tires will be coming off the bike in the spring (though going back on next year)

I don't have any direct experience with either of those Conti tires. I have a set of Continental Town Rides that I really liked for about 1500 miles, but then they started getting a lot of flats. Continental's Top Contact is supposed to be pretty flat resistant, but I think the Contact is relatively ordinary. It sounds like that may be good enough for your expectations.

Also, Continental's tires tend to be narrower than the nominal width, so those would probably be an easy fit for you.

xxguitarist, I'm curious what frame you have and what caliper that is. I see Tektro makes the R740 caliper in the Quartz series, but the specs indicate it's a short (39-49mm) reach...but you must have a longer reach caliper.

xxguitarist, I'm curious what frame you have and what caliper that is. I see Tektro makes the R740 caliper in the Quartz series, but the specs indicate it's a short (39-49mm) reach...but you must have a longer reach caliper.

Hi, it is a R720 by Tektro. The frame is a ~1990 Trek 400, which originally had 700C wheels (and still does) It should appear that it is also 39-49mm reach.

I would up ordering some 700x32 Conti Contacts. I'll give my opinions of them in a few weeks.