Measured Width of Conti GP 4000S II Tires

[Splash]

Hello all.

I measured the inflated (95psi) width of these tires on my bike (and installed on the new Zonda 25mm rims).

I purchased these tires in the advertised 25mm width in the expectation that it would better match the 25mm rims.

I measure 27.01mm at the top of the tire. This is the maximum width as it reduces somewhat as you go further down towards the rim.

I have read that these particular tires tend to be wider than the advertised width. Is this correct?

I am concerned that I now have a wider tire than what I wanted with that light bulb effect / profile on the rim.

If i bought a 25mm wide tire, what should the width at the top of tire be when measured in the inflated state?

Are there other advertised 25mm tires that measure 25mm at the top of the tire, when inflated?

What is the disadvantage of the tire being wider at the top of the tire than at the base of the tire sitting in the rim?


Splash

[kramnnim]

Yes.

Depends on the width of the rim.

Sure.

Rubs some frames.

[Splash]

I have searched the internet and unable to locate the rim section dimensions of the C17 rim. Can someone possibly please provide these dimensions - depth, outer, inner, etc.?

What should the top width of an 25mm tire be to suit this particular rim given these dimensions?

What are some of the other brand tires in the 25mm clincher that measure 25mm at the top when inflated?



Splash

[CiclistiCliff]

buy the 23mm version and you'll be fine.

[cadence90]

Originally Posted by splash

i have searched the internet and unable to locate the rim section dimensions of the c17 rim. Can someone possibly please provide these dimensions - depth, outer, inner, etc.?
Splash

Campagnolo Zonda C17
Rim internal width: 17.0mm
Rim external width: 22.5mm
Milled rim differentiated height: 24-27mm (front) and 27-30mm (rear)

[Llewellyn]

Splash

It's 2mm - not much of a "light bulb effect"!! You'd barely notice it. They are a great riding tyre, just get out there and ride the s**t out of them.

[Splash]

Thanks Guys.

When a rim manufacturer states that their rim suits 25mm tires, what part of the tire is this diemnsion referring to?


Splash

[sitzmark]

Originally Posted by CiclistiCliff

buy the 23mm version and you'll be fine.

This. My 700x23 GP4Ks2 measure 25mm on 24.7mm (brake track) rims. Don't recall bead hook width. IIRC they also measure close to 25mm on a 20mm rim.

[simonov]

Originally Posted by Llewellyn

Splash

It's 2mm - not much of a "light bulb effect"!! You'd barely notice it. They are a great riding tyre, just get out there and ride the s**t out of them.

This. They're great tires and will ride great on those rims as long as there are now clearance issues.

They're also tires that are generously sized. The 23s would probably match up more closely to some other brands' 25s. And as cadence called out, the rims aren't 25mm, they're 22.5mm. So most any brand's 25 is going to create that "lightbulb" effect, not that there's anything wrong with that. 23s would be a better match for the gentle curve you're probably looking for.

That said, I ride wide rims, skinny rims, wide tires, skinny tires, and in all different combinations and given the right pressures the differences are not as dramatic as the magazines would have you believe. Good tires ride well. Crap tires don't. The rest is pretty close to splitting hairs.

[Tony T]

See: http://www.slowtwitch.com/Products/T...view_4056.html

Unfortunately, it is difficult to say exactly how much your tire will ‘swell’ due to the wider rim. As we’ve discussed many times in the past, the size listed on your tire label isn’t always accurate to begin with – and they must make that label assuming a given rim size.

[Tony T]

Here's 23mm and 25mm GP4000's on a 25mm HED Ardennes+ rim:

[oldpotatoe]

Originally Posted by Splash

Hello all.

I measured the inflated (95psi) width of these tires on my bike (and installed on the new Zonda 25mm rims).

I purchased these tires in the advertised 25mm width in the expectation that it would better match the 25mm rims.

I measure 27.01mm at the top of the tire. This is the maximum width as it reduces somewhat as you go further down towards the rim.

I have read that these particular tires tend to be wider than the advertised width. Is this correct?

I am concerned that I now have a wider tire than what I wanted with that light bulb effect / profile on the rim.

If i bought a 25mm wide tire, what should the width at the top of tire be when measured in the inflated state?

Are there other advertised 25mm tires that measure 25mm at the top of the tire, when inflated?

What is the disadvantage of the tire being wider at the top of the tire than at the base of the tire sitting in the rim?


Splash

None, no disadvantage in actual terms of your riding performance. Frame/fork/brake/chainstay clearance is what's most important and reliability.

Also I think 95psi is too high of a pressure for you.

[fignon's barber]

If you're looking for a "smaller"25mm tire, get Veloflex 25mm. They are the same size as a gp4000s 23mm.

[djg21]

Originally Posted by Splash

Hello all.

I measured the inflated (95psi) width of these tires on my bike (and installed on the new Zonda 25mm rims).

I purchased these tires in the advertised 25mm width in the expectation that it would better match the 25mm rims.

I measure 27.01mm at the top of the tire. This is the maximum width as it reduces somewhat as you go further down towards the rim.

I have read that these particular tires tend to be wider than the advertised width. Is this correct?

I am concerned that I now have a wider tire than what I wanted with that light bulb effect / profile on the rim.

If i bought a 25mm wide tire, what should the width at the top of tire be when measured in the inflated state?

Are there other advertised 25mm tires that measure 25mm at the top of the tire, when inflated?

What is the disadvantage of the tire being wider at the top of the tire than at the base of the tire sitting in the rim?

Splash

Go ride your bike! You're over thinking it.

[kramnnim]

Originally Posted by djg21

Go ride your bike! You're over thinking it.

This x 10