Actual width of Conti GP4000S II

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BigPoser
Posts: 172
Joined: Tue Oct 21, 2014 11:42 pm

by BigPoser

Hi All,

I'm currently in the market for some new tires and want to get some Conti GP4000s II in a 25mm to replace my Michelin Pro SC 23mm. Here's my dilemma: One of my bikes has Kinlin XR19W rims and the other has H+Son and I will swap wheels when desired.

My issue is that my Focus has a tighter clearance, on the rear only (about a 1-2mm or so) which is why I'm using the Mich SC 23mm tires. I want to know if I will still have clearance issues with the GP 25mm tires. Sometime later this year I might end up getting new wheels (Pacenti or similar) and also need to know if I'm continue to have issues with the new hoops since they will be wider than my Kinlins.

The 23's are okay, but on long rides with roads that aren't that great, they tend to beat me up a bit and I'd love to get into the wider tire and run lower pressure.

So I measured a few things last night. The width of my 23mm SC tires on my Kinlin rims are 24.68mm. With this set up I have 4.63mm of clearance on my NDS chainstay.

I also measured the width of my Michelin SC 25mm tires that are mounted on H+Son Archetype rims on my other bike and they measured 26.73mm.

Based on those numbers, I would have approx 2.5mm of clearance using the Mich 25mm, however that is using a different rim.

Think I'd be able to fit the 25mm Conti's?

Thanks in advance.

Brandon

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mariovalentim
Posts: 225
Joined: Fri Aug 28, 2015 2:03 am

by mariovalentim

Contis are always wider than advertised imo. My 23mm looks like 25mm and the 25mm looks like 28mm

Grill
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Location: Oop North

by Grill

23.8mm and 25.8mm respectively.

bm0p700f
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by bm0p700f

conti GP4000s 25mm tyres on Kinlin XR22t or the 31t will be 27.5mm wide roughly. It will be tight.

It is not the conti are wider than advertised. On a mavic open pro they come up at the right width and height. Wider rims stop the tyre bulging so much so it sits wider and slightly taller.

It is the bead to bead distance that is important. The bigger this is the wider and taller the tyre will sit.

Marin
Posts: 4035
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

GP 4000s II are about 2mm wider than advertised. My 25s are 27, my 28s are 30mm.

Many other Conti tires, e.g. 4Seasons, GP TT, GP Force run true to size though!

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Frankie - B
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by Frankie - B

From what I have learned talking to a few people in the tire business: road tires may have a 3mm tolerance, wider rims make your tires stand taller and may cause your hand made tire to tear at the bead.
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BigPoser
Posts: 172
Joined: Tue Oct 21, 2014 11:42 pm

by BigPoser

Thanks for the replies. I'll probably have to stick with 23's then as I don't want to get the 25's only to realize that they won't fit.

Trkorb
Posts: 146
Joined: Sat Jan 19, 2013 1:17 am

by Trkorb

I measured some 23mm contis and they came up at 26.4mm on my Bontrager Aeolus wheels.

oreoboreo
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Location: Aloha, Oregon/ Poipu, Kauai Hawaii

by oreoboreo

if people are measuring the tires mounted they will get different measurements depending on the rim width. On my HED c2 wheelset my 23's really look like 25's since they are such a wide rim.
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Sam
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Location: Gothenburg, Sweden

by Sam

Image

Marin
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Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

That picture includes every detail except the resulting width xD

mr4fox
Posts: 276
Joined: Sat May 15, 2010 2:01 pm

by mr4fox

25mm conti Gp4000s II's on my pacenti sl23(v1) rims measured about 26.4mm. Fat and comfy. Kinda like me atm hehe

fogman
Posts: 1066
Joined: Fri Oct 30, 2009 10:36 pm

by fogman

Here are the measurements of Conti GP4000S II (23c and 25c) on my Bora One 35 clinchers (17 mm internal, 24.2 mm external rim width) inflated to 100 psi:

Conti GP4000S II (23c) = 25.4mm
Conti GP4000S II (25c) = 26.7mm
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BrunoDMS
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Joined: Thu Jul 19, 2012 10:24 am

by BrunoDMS

fogman wrote:Here are the measurements of Conti GP4000S II (23c and 25c) on my Bora One 35 clinchers (17 mm internal, 24.2 mm external rim width) inflated to 100 psi:

Conti GP4000S II (23c) = 25.4mm
Conti GP4000S II (25c) = 26.7mm


Weights?
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fogman
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Joined: Fri Oct 30, 2009 10:36 pm

by fogman

Weights of what? Wheels or tires?


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