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Tyre sizing - standard v tubeless GP5000.

by Diggery
Sat, Apr 03, 2021 11:16
7

Was due to go for a big ride this morning, but instead I'm refreshing the tracking details on my new wheels that are due mid ride window and everyone else is out! Conflicted, but excited.

Short version - are tubed and tubeless Contis likely to blow up to the same size?

Bike has 17mm internal rims now, with 25mm GP4000 that measure 26.5 and 'some' clearance. Running DA9000 cantis which are rated at 25mm max.

New rims are 27.5 external, 19mm internal - lighter, wider, aero, tubeless. Ideally I'd like to run 28s on them, tubeless.

I have access to 28mm GP5000, non tubeless to try as well as my 4000 25s. These 28s measure bang on 28 on a 15mm rim.

Plan is to fit tubes and various tyres, check clearances then buy some tubeless tyres in the larger one I'm confident will fit.

I have read 5000s are a bit smaller than 4000s but any variation between tubed and tubeless versions?

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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7 comments

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snappyandrew | 3 years ago
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my experience is that the 4000's were much wider than they said they were but the 5000's are about the size they describe. 

We measured them at LBS when they introduced the 5000's as my bike hasn't got massive clearance and I wanted the widest I could use. 

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hawkinspeter | 3 years ago
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Just thought, why don't I just measure mine?

Front wheel 28mm GP5000TL on Prime Black Edition 60 which is listed as 27.5mm external width gives 28.9mm width of tyre.

Rear wheel 28mm GP5000TL on Prime RP50 which is listed as 25mm external width gives 26.7mm tyre width.

However, my digital caliper is a cheap rubbish one, so those measurements are approximations.

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Diggery replied to hawkinspeter | 3 years ago
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hawkinspeter wrote:

Just thought, why don't I just measure mine?

Front wheel 28mm GP5000TL on Prime Black Edition 60 which is listed as 27.5mm external width gives 28.9mm width of tyre.

Rear wheel 28mm GP5000TL on Prime RP50 which is listed as 25mm external width gives 26.7mm tyre width.

However, my digital caliper is a cheap rubbish one, so those measurements are approximations.

Thank you, very helpful!

My new wheels are Prime black edition 50mm at 19/27.5mm.

Tyre rolling site gives the 25 GP5000 at 26 and TL at 27 so TL possibly larger but from below looks like they may squeeze in. I don't want to make an expensive mistake.

I could save a huge 4W though. Per tyre! 1

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Diggery | 3 years ago
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I figured so but marked and measured seem to vary a good bit!

For those eagerly hanging on the the results:
28 GP5000s on 19mm rims : 28.6mm
25 GP4000s on 19mm rims : 29mm

Both fit, chainstay clearance is tight so can't afford for the TL to grow much over 29.

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check12 | 3 years ago
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check bicycle rolling resistance they have both TL and inner tube tyres with dimensions fitted 

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Diggery replied to check12 | 3 years ago
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check12 wrote:

check bicycle rolling resistance they have both TL and inner tube tyres with dimensions fitted 

Thanks, will do.

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hawkinspeter | 3 years ago
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Never measured them but my uninformed opinion is that they're probably the same size as I can't see any reason for them to be different.

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