Conti GP5000 28 measures 26
#1
Senior Member
Thread Starter
Join Date: Jul 2020
Posts: 702
Bikes: '23 Poseidon Redwood, '07 Specialized Roubaix Comp Triple, '12 Gravity Fixie, '21 Liv Rove 4, '06? Giant EB Spirit
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 345 Post(s)
Liked 237 Times
in
151 Posts
Conti GP5000 28 measures 26
Just replaced a Gatorskin 28 with a GP5000 28 and was surprised how much skinnier the new tire looks. I measured both at the same pressure with the same tube. The Gatorskin measured 28mm whereas the GP5000 was 26mm. Not that big of a deal, but I feel like I could fit a GP5000 32 if it scales the same.
Anyone have a 32 or 30 GP5000 you could measure the width of?
Also, why is there such a discrepancy from the same company. Is it the sidewall strength?
Thanks
Anyone have a 32 or 30 GP5000 you could measure the width of?
Also, why is there such a discrepancy from the same company. Is it the sidewall strength?
Thanks
#2
Cheerfully low end
Join Date: Jun 2020
Posts: 1,965
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Liked 1,040 Times
in
663 Posts
Just replaced a Gatorskin 28 with a GP5000 28 and was surprised how much skinnier the new tire looks. I measured both at the same pressure with the same tube. The Gatorskin measured 28mm whereas the GP5000 was 26mm. Not that big of a deal, but I feel like I could fit a GP5000 32 if it scales the same.
Anyone have a 32 or 30 GP5000 you could measure the width of?
Also, why is there such a discrepancy from the same company. Is it the sidewall strength?
Thanks
Anyone have a 32 or 30 GP5000 you could measure the width of?
Also, why is there such a discrepancy from the same company. Is it the sidewall strength?
Thanks
Otto
Likes For ofajen:
#3
Senior Member
Thread Starter
Join Date: Jul 2020
Posts: 702
Bikes: '23 Poseidon Redwood, '07 Specialized Roubaix Comp Triple, '12 Gravity Fixie, '21 Liv Rove 4, '06? Giant EB Spirit
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 345 Post(s)
Liked 237 Times
in
151 Posts
Thanks for the info. I have 19mm rims (Mavic Open Pro), is there a way to calculate expected widths?
#4
Senior Member
Join Date: Jan 2007
Location: Eastern VA
Posts: 1,702
Bikes: 2022 Fuel EX 8, 2021 Domane SL6, Black Beta (Nashbar frame), 2004 Trek 1000C for the trainer
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 260 Post(s)
Liked 443 Times
in
262 Posts
Wow. I have an two year old 5000 28mm and on a 19mm rim it measures 29mm at 90psi. On a 25mm rim it measures 31mm. Yes the tire manufacturers need to publish width on at least one rim. I guess they sell more tires that way.
#5
Senior Member
Join Date: Apr 2021
Posts: 4,083
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2332 Post(s)
Liked 2,094 Times
in
1,311 Posts
I have a 28mm GP 5000 measuring 26.9 mm on a rim where a 28mm GP4000 used to measure 30.5 mm and a 25 mm used to measure 27.5 mm. These are tubed versions. I am left wondering if I should order 28 mm with the new GP 5000 S tubeless version. I can fit 27.5 mm on my bike but not like over 28.5 mm. At 100 bucks a pop, they could easily show width for 17, 19, and 21 mm internal width to the rim (not the external width). The 25 and 23 GP5000 are almost the same width on 19 mm internal rims
#6
Senior Member
Join Date: Aug 2019
Location: Québec, Canada
Posts: 2,064
Bikes: SL8 Pro, TCR beater
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 957 Post(s)
Liked 562 Times
in
423 Posts
Just replaced a Gatorskin 28 with a GP5000 28 and was surprised how much skinnier the new tire looks. I measured both at the same pressure with the same tube. The Gatorskin measured 28mm whereas the GP5000 was 26mm. Not that big of a deal, but I feel like I could fit a GP5000 32 if it scales the same.
Anyone have a 32 or 30 GP5000 you could measure the width of?
Also, why is there such a discrepancy from the same company. Is it the sidewall strength?
Thanks
Anyone have a 32 or 30 GP5000 you could measure the width of?
Also, why is there such a discrepancy from the same company. Is it the sidewall strength?
Thanks
My previous Cadex 700x25c tires have the same width than my current Schwalbe 700x28c tires. Some are known to be ''truer to size'' than others.
Last edited by eduskator; 02-10-22 at 06:38 AM.
#7
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,613
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
It's like orange juice. Used to come in 1/2 gallon containers (64oz), now it comes in 52oz containers. It's to help hide the fact that cost has gone up; they just give you less but charge the same.
WHATS UP WITH ORANGE JUICE?
On a serious note, it seems weird and undesirable if Conti really changed their tire sizing on an existing production model without at least renaming it slightly like v2 or something.
WHATS UP WITH ORANGE JUICE?
On a serious note, it seems weird and undesirable if Conti really changed their tire sizing on an existing production model without at least renaming it slightly like v2 or something.
Last edited by Sy Reene; 02-10-22 at 06:55 AM.
#9
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,505
Bikes: R3 Disc, Haanjo
Mentioned: 353 Post(s)
Tagged: 1 Thread(s)
Quoted: 20791 Post(s)
Liked 9,436 Times
in
4,663 Posts
Others have already touched on the reasons for discrepancy. If you're trying to maximize your available clearance, it can be frustrating. To make things easier, some manufacturers have adopted and published WAM and RAM specifications (Width/Radius as Mounted), but Conti has been conservative, lagging well behind the leaders in the market.
#10
Senior Member
Thread Starter
Join Date: Jul 2020
Posts: 702
Bikes: '23 Poseidon Redwood, '07 Specialized Roubaix Comp Triple, '12 Gravity Fixie, '21 Liv Rove 4, '06? Giant EB Spirit
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 345 Post(s)
Liked 237 Times
in
151 Posts
Originally Posted by alcjphil;[url=tel:22405074
22405074[/url]]Is that the interior or the exterior width? 19 mm interior would be reasonably wide.
Likes For Sy Reene:
#12
Senior Member
Join Date: Mar 2006
Location: Chicago, IL, USA
Posts: 2,870
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1455 Post(s)
Liked 1,477 Times
in
867 Posts
Worth noting that Conti has 3 versions of this tire. Tubed, Tubeless (TL) and Tubeless/hookless compatible (S TR). I have used all three in various widths, and all measure differently.
Currently:
28mm GP5000 with tubes @80psi on a 23mm external carbon rim (I'm guessing 18-19mm internal but I've never measured) = 26.2mm actual
28mm GP5000 S TR w/o tubes @60psi on a 27mm external/23mm internal hookless carbon rim = 27.8mm actual
I have a set of 32mm TL's, not currently mounted, but I had these on a 19mm i.d. alloy rim last summer and recall them being slightly less than actual 32mm size.
Currently:
28mm GP5000 with tubes @80psi on a 23mm external carbon rim (I'm guessing 18-19mm internal but I've never measured) = 26.2mm actual
28mm GP5000 S TR w/o tubes @60psi on a 27mm external/23mm internal hookless carbon rim = 27.8mm actual
I have a set of 32mm TL's, not currently mounted, but I had these on a 19mm i.d. alloy rim last summer and recall them being slightly less than actual 32mm size.
#13
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,613
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
Worth noting that Conti has 3 versions of this tire. Tubed, Tubeless (TL) and Tubeless/hookless compatible (S TR). I have used all three in various widths, and all measure differently.
Currently:
28mm GP5000 with tubes @80psi on a 23mm external carbon rim (I'm guessing 18-19mm internal but I've never measured) = 26.2mm actual
28mm GP5000 S TR w/o tubes @60psi on a 27mm external/23mm internal hookless carbon rim = 27.8mm actual
I have a set of 32mm TL's, not currently mounted, but I had these on a 19mm i.d. alloy rim last summer and recall them being slightly less than actual 32mm size.
Currently:
28mm GP5000 with tubes @80psi on a 23mm external carbon rim (I'm guessing 18-19mm internal but I've never measured) = 26.2mm actual
28mm GP5000 S TR w/o tubes @60psi on a 27mm external/23mm internal hookless carbon rim = 27.8mm actual
I have a set of 32mm TL's, not currently mounted, but I had these on a 19mm i.d. alloy rim last summer and recall them being slightly less than actual 32mm size.
Likes For Sy Reene:
#14
Method to My Madness
Join Date: Nov 2020
Location: Orange County, California
Posts: 3,544
Bikes: Trek FX 2, Cannondale Synapse, Cannondale CAAD4, Santa Cruz Stigmata GRX
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 1876 Post(s)
Liked 1,411 Times
in
979 Posts
#15
Senior Member
Thread Starter
Join Date: Jul 2020
Posts: 702
Bikes: '23 Poseidon Redwood, '07 Specialized Roubaix Comp Triple, '12 Gravity Fixie, '21 Liv Rove 4, '06? Giant EB Spirit
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 345 Post(s)
Liked 237 Times
in
151 Posts
Like ofajen said it is the new ETRTO standard. If you think installing GP5K 28 mm in a 19C rim is surprising, imagine mine when I installed GP5K 25 mm in a 17C rim. But the tires do grow wider after a few cycles of pre-ride inflation and riding.
Part of me wants to order the 32mm versions based on how skinny these are (hoping they match the 28mm width of the Gatorskins) - I like me some wide tires
#16
Senior Member
Thread Starter
Join Date: Jul 2020
Posts: 702
Bikes: '23 Poseidon Redwood, '07 Specialized Roubaix Comp Triple, '12 Gravity Fixie, '21 Liv Rove 4, '06? Giant EB Spirit
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 345 Post(s)
Liked 237 Times
in
151 Posts
Its funny, after a day of full inflation, it is measuring 27mm. I rechecked the Gatorskins, which are slightly more than 27mm but *look* wider for some reason.
Weird.
I'll shut up and ride now
Weird.
I'll shut up and ride now