Tire Size

[ttaylor508]

So this thread is very timely for me as I was considering going with a skinnier tire. I currently have Specialized Roubaix 700 x 23/25c tires. DH has 700 x 23/23c and his tires are noticeably skinnier than mine. Does anyone know what the third number measurement means (/25c or /23c)?

[boy in a kilt]

In theory, those numbers say something about the width of the tire. However, a 700x25C Specialized tire may be wider or narrower than a Vittoria 700x25C.

Tire size is one of those things you have to figure out on your own. For general riding around, I like 700x28 or 700x32. Once in a while I get a wild hair and go up to 700x35 or 700x37. Not fast in any sense of the word, but very comfortable and I never got flats with the 700x37's.

[aicabsolut]

So this thread is very timely for me as I was considering going with a skinnier tire. I currently have Specialized Roubaix 700 x 23/25c tires. DH has 700 x 23/23c and his tires are noticeably skinnier than mine. Does anyone know what the third number measurement means (/25c or /23c)?

I don't know why there are 3 numbers (usually there are just 2), but I do know that Specialized 23s tend to look a lot more like 25s. Depending on shape and tread, I've seen some 23s of other brands that look more like 20s.

[ttaylor508]

Both are Specialized tires, DH's tarmac has Specialized Mondo and my Ruby has Specialized Roubaix. I did check the Specialized site and it says that 23 is the radius and the 25 is the casing. Still not exactly sure what that means, but the Mondo's are noticeably narrower. Don't know if I will go with another Specialized tire anyway, I am leaning towards the Vittoria Rubino Pros.

[aicabsolut]

Hm.. weird. I guess then I'd treat those like 25s. The Mondos are more of a racing tire, so they may be closer to a true 23.

Try Michelin Pro Race tires. Even if you don't race, they are nice performing tires. I train and race on mine. They maybe don't have the longest life, but mine are doing fine after a few thousand miles. The back one is looking kind of iffy lately, but I think that's from all the trainer warmups during race season. I run Pro2s still, but the Pro3s are supposed to be more durable. They corner sooo much better than Specialized tires IMO and are pretty good in the wet.

I've also heard good things about Continental 4000 series tires. They are supposed to be pretty bombproof but offer race worthy performance.

[spokewench]

When I raced, I used to ride 700 x 19s. They are very narrow, give a harsher ride to your bike and you have to be careful cornering in rain; but I truthfully never had a problem with them. It probably also helps if you are lightweight to run a small tire.

I don't race anymore, so I run a 700 x 23. It is a more comfortable ride and more forgiving.

spoke

[tzvia]

I ran a Vittoria Competition 20c in the back, and a Continental Grand Prix 23c front for a while a few years ago, and found the combination very precise but the low volume 20c just pounded my fillings out. So when I bought a new bike a few months ago, I tossed those aside and bought Vredestein Fortezza TriComps in 23c. What a difference. They roll light and are light weight, have just enough 'give' to take the sting out of the road and they corner well. I hear that they don't wear well, guess for my $110 bucks I'm gonna find out! They feel more like tubulars (which I used to use) than any other clincher I have tried. My Ruby came with Specialized tires (of course) but I found them heavy and unresponsive. They also looked larger than 23c and are taller/wider than the Vredesteins. The bike livened up with the Vredesteins and I did not have to sacrifice my dental work!

[OakLeaf]

tz, why a wider tire in front? Typically on motorcycles (and open wheel cars FWIW), the rear tire is wider for a larger and more rounded contact patch on the drive wheel, and lighter more precise steering in front.