GP5000 test results

[bikinchris]

Three of the top 5 best tires for low rolling resistance are made by Continental.

https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-5000-tl-2018

Clif notes:
The top tire is a Vittoria meant for racing and will not last long.
The GP5000 that tested second lowest was a tubeless tire.
The third place tire was a Vittoria tubular
The forth place was the Continental tire meant for racing
The 5th place tire was the regular version of the GP5000


So now, you can expect a couple more people claim they can't stand Continental tires. Fair enough. As for me, my butt can take a rougher ride as long as my ride doesn't get interrupted by fixing a flat.

[Mark McM]

A comment about tubeless tires and the www.bicyclerollingresistance.com test results:

Inner tubes also contribute to rolling resistance, and the thickness and material of the inner tube make a difference. The standard procedure for the www.bicyclerollingresistance tests is to use a "standard" 100 gram butyl inner tube. However, if you look further into the web page, he has also compared the rolling resistance of the same tire with a standard butyl inner tube, a lightweight butyl inner tube, and a latex inner tube, and found that the latex tube saves several Watts. If you extrapolate the results of the non-tubeless GP5000 clincher and the latex inner tube results, it is likely that the non-tubeless GP5000 will have a slightly lower rolling resistance than the tubeless GP5000 tire.

[yinzerniner]

A comment about tubeless tires and the www.bicyclerollingresistance.com test results:

Inner tubes also contribute to rolling resistance, and the thickness and material of the inner tube make a difference. The standard procedure for the www.bicyclerollingresistance tests is to use a "standard" 100 gram butyl inner tube. However, if you look further into the web page, he has also compared the rolling resistance of the same tire with a standard butyl inner tube, a lightweight butyl inner tube, and a latex inner tube, and found that the latex tube saves several Watts. If you extrapolate the results of the non-tubeless GP5000 clincher and the latex inner tube results, it is likely that the non-tubeless GP5000 will have a slightly lower rolling resistance than the tubeless GP5000 tire.

While the GP5000 Clincher with a latex tube might well test better than the GP5000 TL, you can't assume it will based off of extrapolation from the test mentioned. The Schwalbe One Tubeless used in that test from 2014 weighed 344g, while the Schwalbe One V-Guard weighed 244g with tubes of 100g butyl, 80g latex and 70g lite butyl. The latex tube was around 1w more efficient while 20g lighter.

Also the GP5000s use different TPI casings, have different bead shapes, wall thicknesses etc, so it's impossible to extrapolate based on the variables you listed.

As stated before I don't think you're wrong as it's impossible to prove without actual testing, but you're wrong to come to the conclusion you have based on the limited and faulty variables you're applying.

[azrider]

So now, you can expect a couple more people claim they can't stand Continental tires. Fair enough. As for me, my butt can take a rougher ride as long as my ride doesn't get interrupted by fixing a flat.

Amen. All about what 'keeps' me on road, instead of few watts saved or smoother feel.

#teamconti

[azrider]

A comment about tubeless tires and the www.bicyclerollingresistance.com test results:

Inner tubes also contribute to rolling resistance, and the thickness and material of the inner tube make a difference. The standard procedure for the www.bicyclerollingresistance tests is to use a "standard" 100 gram butyl inner tube. However, if you look further into the web page, he has also compared the rolling resistance of the same tire with a standard butyl inner tube, a lightweight butyl inner tube, and a latex inner tube, and found that the latex tube saves several Watts. If you extrapolate the results of the non-tubeless GP5000 clincher and the latex inner tube results, it is likely that the non-tubeless GP5000 will have a slightly lower rolling resistance than the tubeless GP5000 tire.

Not to get into thread drift but after about 200 miles I just replaced my commuter tires from thorn resistant tubes to regular tubes......holeee chit what a diff

[wasfast]

Al Morrison's data showed a consistent improvement with latex and not much difference between "normal/standard" butyl and lightweight butyl. The difference was consistent across various tires. I definitely prefer latex but it doesn't come without some tradeoffs.
http://www.biketechreview.com/tires_old/images/AFM_tire_testing_rev9.pdf

[R3awak3n]

if you guys are having that many flats with vittoria or other more supple tires then I understand if you want to ride what you want to ride. I do have flats but not enough that will make me change my tire choice. Now, I never ridden the 5000 but I have ridden the 4000 and to me the vittoria G+ is a better tire...

Now, don't get me wrong, I have had tires made out of butter so I understand. Veloflex is terrible to me, I had one last 100 miles... Another last 300.

I am team, ride whatever you want.

[bikinchris]

if you guys are having that many flats with vittoria or other more supple tires then I understand if you want to ride what you want to ride. I do have flats but not enough that will make me change my tire choice. Now, I never ridden the 5000 but I have ridden the 4000 and to me the vittoria G+ is a better tire...

Now, don't get me wrong, I have had tires made out of butter so I understand. Veloflex is terrible to me, I had one last 100 miles... Another last 300.

I am team, ride whatever you want.

The only time I ever have flats is when my tire is totally worn out and I don't replace it. But I don't ride racing tires. I have seen most of these racing tires fall apart on our local roads. I have had customers experiment with all of the common brands (Schwalbe, Vittoria, Veloflex, Hutchinson etc. etc. ) and they go back to Continental. It really ticks off the group rides when you keep getting flats and they don't.

[Keith A]

Thanks for the link. I haven't ridden Continental tires much...no particular reason, but the GP5000's have piqued my interest.

[Clancy]

The only time I ever have flats is when my tire is totally worn out and I don't replace it. But I don't ride racing tires. I have seen most of these racing tires fall apart on our local roads. I have had customers experiment with all of the common brands (Schwalbe, Vittoria, Veloflex, Hutchinson etc. etc. ) and they go back to Continental. It really ticks off the group rides when you keep getting flats and they don't.

You guys wait when someone flats?

How novel

[buddybikes]

But they don't have nice tan sidewalls like Vittoria's...
Let's get to priorities here

[Davist]

if you guys are having that many flats with vittoria or other more supple tires then I understand if you want to ride what you want to ride. I do have flats but not enough that will make me change my tire choice. Now, I never ridden the 5000 but I have ridden the 4000 and to me the vittoria G+ is a better tire...
.


2nd hand, my buddy had 4ks, went to Vittoria G+ and loved them, wore out a couple pairs (race tires used on street, so NBD) and now had 5ks and likes them better.

As for me, I like the 4ks, run 28s on wide rims (about 33 or so) with "absurdly low" pressure per some of you guys (80max) keep up and have fun with basically 0 flats this year. Currently running 4 seasons for winter (after having sidewall rips years ago, but got a deal from forum sponsor Bike Tires Direct) and like them better that my Challenge Strada Biancas. So, I'm an outlier.. I may just go to road+ and 2" tires at 30psi soon enough :)

[Alan]

Was looking at this data and looks like its about 8 watts difference between the 5000 tire and the 4 Season tire that I ride year around as I ride on bike trails which have a lot of junk on them.

My q is how noticeable will this be? Is this really 8 watts which for me would be about 5% improvement in FTP? Do you think it would really be this noticeable or is it theoretical?

I know I could try it out and do a test but that's a lot of work. Interested in others feedback etc.

Alan

[R3awak3n]

But they don't have nice tan sidewalls like Vittoria's...
Let's get to priorities here

tanwalls is so 2017

2nd hand, my buddy had 4ks, went to Vittoria G+ and loved them, wore out a couple pairs (race tires used on street, so NBD) and now had 5ks and likes them better.

As for me, I like the 4ks, run 28s on wide rims (about 33 or so) with "absurdly low" pressure per some of you guys (80max) keep up and have fun with basically 0 flats this year. Currently running 4 seasons for winter (after having sidewall rips years ago, but got a deal from forum sponsor Bike Tires Direct) and like them better that my Challenge Strada Biancas. So, I'm an outlier.. I may just go to road+ and 2" tires at 30psi soon enough :)

I am going to try the 5ks in 32mm tubeless when I need new tires for that bike so we will see. I have no brand loyalty, just want to ride good tires :)

[yinzerniner]

Was looking at this data and looks like its about 8 watts difference between the 5000 tire and the 4 Season tire that I ride year around as I ride on bike trails which have a lot of junk on them.

My q is how noticeable will this be? Is this really 8 watts which for me would be about 5% improvement in FTP? Do you think it would really be this noticeable or is it theoretical?

I know I could try it out and do a test but that's a lot of work. Interested in others feedback etc.

Alan

The difference will not be noticeable in everyday real-world riding, however it should be noticeable if you're doing races or TT's. Then again if you're doing those you might not opt for the GP5000s in the first place. Someone tested that with aero and rolling resistance drag factored in and found a 4.3% gain over the GP4000 but that they're still slower than the dedicated TT tire:
https://www.aero-coach.co.uk/gp-5000-data

Basically the GP5000 is getting near race day tire performance but much better wear, and much better flat protection if you're going tubeless. Not the end all be all, but the safe and fun choice for almost everyone. While other tires will probably have a more supple ride, or go faster, or have better flat protection I doubt any will do all three better than the GP5000. However you're going to pay for it as they are pricey AF.

[Mark McM]

While the GP5000 Clincher with a latex tube might well test better than the GP5000 TL, you can't assume it will based off of extrapolation from the test mentioned. The Schwalbe One Tubeless used in that test from 2014 weighed 344g, while the Schwalbe One V-Guard weighed 244g with tubes of 100g butyl, 80g latex and 70g lite butyl. The latex tube was around 1w more efficient while 20g lighter.

You're right, it makes no sense to compare the Schwalbe One Tubeless with the Schwalbe One V-guard (standard clincher), because they are completely different tires. Instead, compare the Schwalbe One V-guard with the standard butyl tube and the same tire with a latex tube. The latex tube saves 2 Watts. It is reasonable to assume that the latex GP 5000 with a latex tube would also be about 2 Watts faster than the GP 5000 with a standard butyl tube - which would also put the GP 5000 with latex tube at about the same drag as the GP 5000 TL. And between different production runs of each tire, the GP 5000 w/latex could very well be faster than the GP 5000 TL.

[FlashUNC]

Did it come in #1 again on the "Still feels like a garden hose taped to the rim" test?

[yinzerniner]

You're right, it makes no sense to compare the Schwalbe One Tubeless with the Schwalbe One V-guard (standard clincher), because they are completely different tires. Instead, compare the Schwalbe One V-guard with the standard butyl tube and the same tire with a latex tube. The latex tube saves 2 Watts. It is reasonable to assume that the latex GP 5000 with a latex tube would also be about 2 Watts faster than the GP 5000 with a standard butyl tube - which would also put the GP 5000 with latex tube at about the same drag as the GP 5000 TL. And between different production runs of each tire, the GP 5000 w/latex could very well be faster than the GP 5000 TL.

Again, you're wrong because you're arriving to the wrong corrective variable (2 watts) based off a non-commonality (Shwalbe vs Conti tires). Your corrective variable shouldn't be in watts but rather in percentage, and it should be to the closest possible comparative tire to the GP5k, which is the GP4k.

The percentage difference between the GP4k latex vs butyl is roughly a 13.8% difference, and if you apply that percentage gain in the tube switch to the GP5k clincher you get RR wattages of 8.6, 9.2, 10.4, and 12.2 for 120, 100, 80 and 60 psi respectively, which are still higher than the GP5k TL figures of 8.3, 8.9, 9.9 and 11.6. And that is with a ~8% weight difference (GP5K latex is 221+80g tube, while GP5k TL is 295+32g sealant) and ~4% width difference (GP5K 26mm, GP5k TL 27) as well. The cumulative difference is about 4% between the non-tested extrapolated figure of GP4k Latex and the tested GP5k TL so could easily swing either way when actually tested.

But based off the available information it's impossible to say that the latex tubed GP5K will be faster than the GP5K TL.

Data collected from:
GP4K Lates vs GP4K Butyl vs GP5K Butyl:
https://www.bicyclerollingresistance.com/road-bike-reviews/compare/continental-grand-prix-4000s-ii-2014-vs-continental-grand-prix-4000s-ii-latex-tube-2014-vs-continental-grand-prix-5000-2018
GP5K Tubeless:
https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-5000-tl-2018
Stans Sealant Weight (108g/100ml):
https://singletrackworld.com/forum/topic/tubeless-weight-saving/

[azrider]

Again, you're wrong because you're arriving to the wrong corrective variable (2 watts) based off a non-commonality (Shwalbe vs Conti tires). Your corrective variable shouldn't be in watts but rather in percentage, and it should be to the closest possible comparative tire to the GP5k, which is the GP4k.

The percentage difference between the GP4k latex vs butyl is roughly a 13.8% difference, and if you apply that percentage gain in the tube switch to the GP5k clincher you get RR wattages of 8.6, 9.2, 10.4, and 12.2 for 120, 100, 80 and 60 psi respectively, which are still higher than the GP5k TL figures of 8.3, 8.9, 9.9 and 11.6. And that is with a ~8% weight difference (GP5K latex is 221+80g tube, while GP5k TL is 295+32g sealant) and ~4% width difference (GP5K 26mm, GP5k TL 27) as well. The cumulative difference is about 4% between the non-tested extrapolated figure of GP4k Latex and the tested GP5k TL so could easily swing either way when actually tested.

But based off the available information it's impossible to say that the latex tubed GP5K will be faster than the GP5K TL.

Data collected from:
GP4K Lates vs GP4K Butyl vs GP5K Butyl:
https://www.bicyclerollingresistance.com/road-bike-reviews/compare/continental-grand-prix-4000s-ii-2014-vs-continental-grand-prix-4000s-ii-latex-tube-2014-vs-continental-grand-prix-5000-2018
GP5K Tubeless:
https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-5000-tl-2018
Stans Sealant Weight (108g/100ml):
https://singletrackworld.com/forum/topic/tubeless-weight-saving/

Check out the big brain on Brad.........;)

[Mark McM]

Again, you're wrong because you're arriving to the wrong corrective variable (2 watts) based off a non-commonality (Shwalbe vs Conti tires). Your corrective variable shouldn't be in watts but rather in percentage, and it should be to the closest possible comparative tire to the GP5k, which is the GP4k.

The percentage difference between the GP4k latex vs butyl is roughly a 13.8% difference, and if you apply that percentage gain in the tube switch to the GP5k clincher you get RR wattages of 8.6, 9.2, 10.4, and 12.2 for 120, 100, 80 and 60 psi respectively, which are still higher than the GP5k TL figures of 8.3, 8.9, 9.9 and 11.6. And that is with a ~8% weight difference (GP5K latex is 221+80g tube, while GP5k TL is 295+32g sealant) and ~4% width difference (GP5K 26mm, GP5k TL 27) as well. The cumulative difference is about 4% between the non-tested extrapolated figure of GP4k Latex and the tested GP5k TL so could easily swing either way when actually tested.

But based off the available information it's impossible to say that the latex tubed GP5K will be faster than the GP5K TL.

Data collected from:
GP4K Lates vs GP4K Butyl vs GP5K Butyl:
https://www.bicyclerollingresistance.com/road-bike-reviews/compare/continental-grand-prix-4000s-ii-2014-vs-continental-grand-prix-4000s-ii-latex-tube-2014-vs-continental-grand-prix-5000-2018
GP5K Tubeless:
https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-5000-tl-2018
Stans Sealant Weight (108g/100ml):
https://singletrackworld.com/forum/topic/tubeless-weight-saving/

Well, we're both wrong then (although the data suggest you may be the more wrong).

I'm not sure that the comparison between the latex and butyl tubes is proportional - much of the data suggests that the difference is more of a (constant offset). If the www.bicyclerollingresistance test between the GP4000II (with butyl and latex tubes) and the GP5000TL, the difference in rolling resistance between butyl latex only varies from 1.6 W to 2.2 W, even as the pressure is cut in half (from 120 psi to 60 psi). The greater variation in the Schwalbe V-Guard tire between butyl and latex may be due to this tire being much heavier and lossier, so that the tire itself plays a larger role (by all measures, the GP5000 is more similar to the GP4000II than to the Schwalbe V-Guard).

Interestingly, the GP4000II vs. GP5000TL test actually shows that at lower pressures, the GP4000II with latex has less resistance than the GP5000TL. Since the GP5000 has already tested to have lower drag than the GP4000II at all pressures with butyl tubes, and that tires with latex tubes have lower rolling resistance than tires with butyl tubes, it is reasonable to guess that the GP5000 with a latex tube will have lower drag than the GP500TL (at least at lower pressures).

But we don't have to guess about this, as apparently it has already been tested, and the GP5000 with latex tube was found to have a lower rolling resistance than the GP5000 TL:

https://www.aero-coach.co.uk/gp-5000-tubeless-data

https://d2f0ora2gkri0g.cloudfront.net/7b/66/7b663672-0dec-4057-825f-2d84d17beea4.png

[saab2000]

Did it come in #1 again on the "Still feels like a garden hose taped to the rim" test?

I have a set of GP4000s and running on wide rims at appropriate pressure (80 PSI or so for my 23s) they are surprisingly decent. I got them as part of a wheel deal a number of years ago and expected to hate them but didn't. Zero flats over the time I've had them and far, far better ride quality than I expected.

My mind has been opened to Continental clinchers.

[yinzerniner]

Well, we're both wrong then (although the data suggest you may be the more wrong).

I'm not sure that the comparison between the latex and butyl tubes is proportional - much of the data suggests that the difference is more of a (constant offset). If the www.bicyclerollingresistance test between the GP4000II (with butyl and latex tubes) and the GP5000TL, the difference in rolling resistance between butyl latex only varies from 1.6 W to 2.2 W, even as the pressure is cut in half (from 120 psi to 60 psi). The greater variation in the Schwalbe V-Guard tire between butyl and latex may be due to this tire being much heavier and lossier, so that the tire itself plays a larger role.

Interestingly, the GP4000II vs. GP5000TL test actually shows that at lower pressures, the GP4000II with latex has less resistance than the GP5000TL. Since the GP5000 has already tested to have lower drag than the GP4000II at all pressures with butyl tubes, and that tires with latex tubes have lower rolling resistance than tires with butyl tubes, it is reasonable to guess that the GP5000 with a latex tube will have lower drag than the GP500TL (at least at lower pressures).

But we don't have to guess about this, as apparently it has already been tested, and the GP5000 with latex tube was found to have a lower rolling resistance than the GP5000 TL:

https://www.aero-coach.co.uk/gp-5000-tubeless-data

https://d2f0ora2gkri0g.cloudfront.net/7b/66/7b663672-0dec-4057-825f-2d84d17beea4.png

I honestly don't know where you're getting a constant offset since the data proves otherwise when it comes to RR differences based on tube type. The difference in latex vs butyl for the GP4k was 1.6,1.8,1.9 and 2.2 (gradual) while the Schwalbe was 1.5,1.7,2.1 and 2.4 (big jump at 80-100 psi change). The offset isn't constant at all, as the Schwalbe has lower differences at the higher pressures but higher differences at the lower pressures when compared to the GP4k.

Again you're reaching a preconcieved conclusion based off of a faulty understanding of the facts.

At NO POINT do I suggest that the GP5K TL will be "faster" than the GP5K with a latex tube. I only state that it's impossible to ascertain the correct conclusion based off the information from bicyclerollingresistance.com and AeroCoachLTD.

The AeroCoachLTD test doesn't mention the total weights of the tires and tubes/sealant. This is pretty important, as Vittoria latex tubes are either 75 or 85g for the 19-24 or 25-28 and the test also uses 50ml of sealant with the GP5K TL. The weight penalty is a min of ~40g to a max of ~55g depending on the tubes and sealants used. That's a pretty considerable weight difference of 13-19% depending on what's used, which could easily explain the 1.2W difference between the clincher and tubeless GP5Ks since a 20g weight difference in butyl tubes created wattage differences of .8-1.2W when testing the different tubes used in the Schwalbe:
https://www.bicyclerollingresistance.com/specials/schwalbe-one-tubeless-clincher

And it was found that adding sealant affects RR, although it's not as stark as the tube change:
https://www.bicyclerollingresistance.com/specials/road-bike-tubeless-sealant
Also the test above shows that effect of tubeless sealant on rolling resistance isn't proportional, as the RR difference from 0 to 20ml is much less than 20 to 40ml. The author guessed that the differences accelerate because at 20ml of sealant a good amount is stuck to the rim/bead so it doesn't effect rolling resistance. Could an even larger jump of sealant from 20ml (BRR test) to 50ml (ACLtd test) have caused an even larger change in rolling resistance? Possible, but not 100% proven.

I've stated all along that it's impossible to know which tire is faster all things being equal until a test gets just about everything equal as possible including total tire plus tube/sealant weight, pressure, measured width/height, etc. Then again, the AeroCoach LTD seems to get it as close as possible to typical riding conditions, with the caveat that the tubeless setup is MUCH more practical for everyday use than the clincher and latex tube setup, but the typical clincher an latex tube combo will be faster and will be the better choice for raceday and pure performance setups.

Now my big brain needs to get back to important things, like Cardi B and the perfect implementation of the phrase "I'll buy THAT for a dollar!"

[azrider]

I have a set of GP4000s and running on wide rims at appropriate pressure (80 PSI or so for my 23s) they are surprisingly decent. I got them as part of a wheel deal a number of years ago and expected to hate them but didn't. Zero flats over the time I've had them and far, far better ride quality than I expected.

My mind has been opened to Continental clinchers.

Well now how big a fellar are ya ?? :p

We're much the same in the sense that I typically run GP4000s, on wide rims, only diff being pressure (90 PSI for 25s) and for my 6'2 170ish frame it's, as you say, surprisingly decent.

FWIW I do run Gatorskins from October through February (crits start early here :)) and switch to GP4000s for 'faster' months so not sure if that's helping the GP's feel better or I guess I'm just not that good a rider but to compare them to riding on garden hose......c'mon now :rolleyes:

The one thing I do miss is how the CorsaG's looked on my bike......so there's that

https://forums.thepaceline.net/showthread.php?t=160115&highlight=workhorse&page=2

[Bob Ross]

You guys wait when someone flats?

How novel


True story: Was leading a Club ride 9 or 10 years ago and a guy gets a flat. I stop the group, and proceed to help change his tire. As I'm assisting he looks me in the eye and in complete seriousness asks "Hold on, so you're not really an A rider?"

[Mark McM]

I honestly don't know where you're getting a constant offset since the data proves otherwise when it comes to RR differences based on tube type. The difference in latex vs butyl for the GP4k was 1.6,1.8,1.9 and 2.2 (gradual) while the Schwalbe was 1.5,1.7,2.1 and 2.4 (big jump at 80-100 psi change). The offset isn't constant at all, as the Schwalbe has lower differences at the higher pressures but higher differences at the lower pressures when compared to the GP4k.

Again you're reaching a preconcieved conclusion based off of a faulty understanding of the facts.

I didn't say that the butyl-latex difference was a constant offset, I said it was closer to a constant offset (than it was a percentage of tire weight) - i.e., a first order approximation. As an engineer, I know that handling many non-linear affects is made easier by using siimplified models. For example, rolling resistance drag is often expressed using a single linear coefficient (Crr), which is constant with speed. In reality, testing has shown that rolling resistance actually increases with speed - but the variation with speed is small in comparison with the non-speed varying coefficient, so that for most purposes we can ignore speed affects. So too, all the tests of latex tube have shown that at the pressure values of interest, the difference between a latex tube and a standard butyl tube is roughly 2 Watts - close enough for a first order approximation.[/QUOTE]

At NO POINT do I suggest that the GP5K TL will be "faster" than the GP5K with a latex tube. I only state that it's impossible to ascertain the correct conclusion based off the information from bicyclerollingresistance.com and AeroCoachLTD.

Likewise, at no point did I state that the GP5000K with latex absolutely was faster than the GP5000TL, just that extrapolating from other data it appeared it was likely (first order approximation).

The AeroCoachLTD test doesn't mention the total weights of the tires and tubes/sealant. This is pretty important, as Vittoria latex tubes are either 75 or 85g for the 19-24 or 25-28 and the test also uses 50ml of sealant with the GP5K TL. The weight penalty is a min of ~40g to a max of ~55g depending on the tubes and sealants used. That's a pretty considerable weight difference of 13-19% depending on what's used, which could easily explain the 1.2W difference between the clincher and tubeless GP5Ks since a 20g weight difference in butyl tubes created wattage differences of .8-1.2W when testing the different tubes used in the Schwalbe:
https://www.bicyclerollingresistance.com/specials/schwalbe-one-tubeless-clincher

And it was found that adding sealant affects RR, although it's not as stark as the tube change:
https://www.bicyclerollingresistance.com/specials/road-bike-tubeless-sealant
Also the test above shows that effect of tubeless sealant on rolling resistance isn't proportional, as the RR difference from 0 to 20ml is much less than 20 to 40ml. The author guessed that the differences accelerate because at 20ml of sealant a good amount is stuck to the rim/bead so it doesn't effect rolling resistance. Could an even larger jump of sealant from 20ml (BRR test) to 50ml (ACLtd test) have caused an even larger change in rolling resistance? Possible, but not 100% proven."

If you are that interested, you could probably contact Aero Coach for that information. In any case, here is another report of a direct comparison between the GP5000 and GP5000TL that does give that information:
http://www.cyclesetforme.fr/test-de-roulement-continental-gp-5000-et-5000-tl/

In this test, the GP5000TL did slightly better than the GP5000 with latex - but only by about 1% (vs. the GP5000 being 4.5% better in the Aero Coach test). Possibly the differences were in test conditions, or perhaps manufacturing batch variations in manufacturing the tires. In any case, it appears the data is pointing toward the GP5000 with latex being as good as, or a little better, than the GP5000TL.

[mtechnica]

Was looking at this data and looks like its about 8 watts difference between the 5000 tire and the 4 Season tire that I ride year around as I ride on bike trails which have a lot of junk on them.

My q is how noticeable will this be? Is this really 8 watts which for me would be about 5% improvement in FTP? Do you think it would really be this noticeable or is it theoretical?

I know I could try it out and do a test but that's a lot of work. Interested in others feedback etc.

Alan

I’ve had 4 seasons and I can tell a difference between them and gp4000s, they do feel like they roll slower.

[Mark McM]

I’ve had 4 seasons and I can tell a difference between them and gp4000s, they do feel like they roll slower.

That's my experience as well. When switching between bikes with GP4Seasons and GP4000SII tires, my impression is that I average about 1/2 - 1 mph slower on the GP4Season tires. Of course, there may be other differences in the bikes and riding conditions other than the tires, but looking at the speed & power for the rides, and the measured differences in rolling resistance, the numbers suggest that the speed difference I perceive is in the ball park of what would be expected.

[dton]

I’ve had 4 seasons and I can tell a difference between them and gp4000s, they do feel like they roll slower.

+1 same.

Its important to note that the "7-8 Watt" difference is per tire, and therefore with two tires, the difference would be more like 14-16 Watts - a not insignificant value. If you're at your near your FTP, you're damn well going to notice that difference. But if you're not that type of rider than I doubt the difference will matter much.

[yinzerniner]

I didn't say that the butyl-latex difference was a constant offset, I said it was closer to a constant offset (than it was a percentage of tire weight) - i.e., a first order approximation. As an engineer, I know that handling many non-linear affects is made easier by using siimplified models. For example, rolling resistance drag is often expressed using a single linear coefficient (Crr), which is constant with speed. In reality, testing has shown that rolling resistance actually increases with speed - but the variation with speed is small in comparison with the non-speed varying coefficient, so that for most purposes we can ignore speed affects. So too, all the tests of latex tube have shown that at the pressure values of interest, the difference between a latex tube and a standard butyl tube is roughly 2 Watts - close enough for a first order approximation.

I understand that with engineers for quicker answers you have to implement simplifications, but in this case I disagree with your conclusion that the different figures more closely approximate a constant offset, as well as your conclusion that the offset is 2w. With the figures listed before there's a clear trend that the butyl-latex difference gets larger as the pressure is lessened which to me doesn't signify constant offset at all, and even if you average out the figures listed they come up with 1.875w and 1.925w. Rounding up to 2w would represent margins of error of 6.25% and 3.75%, not insignificant numbers when the differences in rolling resistance seem to lie in the 1-5% range.

Likewise, at no point did I state that the GP5000K with latex absolutely was faster than the GP5000TL, just that extrapolating from other data it appeared it was likely (first order approximation).

Fully understood, I just think your extrapolation is incorrect based on how you're implementing the actual figures, and also how you've created figures that are oversimplified or rounded to suit your preconceived notions (see above and below).

If you are that interested, you could probably contact Aero Coach for that information. In any case, here is another report of a direct comparison between the GP5000 and GP5000TL that does give that information:
http://www.cyclesetforme.fr/test-de-roulement-continental-gp-5000-et-5000-tl/

In this test, the GP5000TL did slightly better than the GP5000 with latex - but only by about 1% (vs. the GP5000 being 4.5% better in the Aero Coach test). Possibly the differences were in test conditions, or perhaps manufacturing batch variations in manufacturing the tires. In any case, it appears the data is pointing toward the GP5000 with latex being as good as, or a little better, than the GP5000TL.

Again you're mixing up numbers just to prove your preconceived point, as the test methodologies, the measured differences and wattage/percentage differences aren't analogous. The french test is totally different from the BRR and ACltd tests, and the percentages cannot be compared to one another, nor can the wattages since the testing methodologies aren't consistent. One test is for power at one speed, another is for power at another speed, one is for "power to overcome," etc. etc.

Again, I don't think your conclusion is wrong, I just think that how you came up the conclusion is problematic for the reasons stated. I'll let others decide based on their own noodles.

[Mark McM]

Again you're mixing up numbers just to prove your preconceived point, as the test methodologies, the measured differences and wattage/percentage differences aren't analogous. The french test is totally different from the BRR and ACltd tests, and the percentages cannot be compared to one another, nor can the wattages since the testing methodologies aren't consistent. One test is for power at one speed, another is for power at another speed, one is for "power to overcome," etc. etc.

Huh? I don't understand what you are getting at here. I didn't make any comparisons between tests, just pointed out the results of each test. It sounds like you're the one jumping to conclusions here. It's like you're grasping at straws just to maintain your narrative of, "you're wrong!".

[BikeNY]

I thought we've determined that these drum tests don't do a good job of predicting rolling resistance on an actual road with an actual rider on the bike?

[Mark McM]

I thought we've determined that these drum tests don't do a good job of predicting rolling resistance on an actual road with an actual rider on the bike?

Yes, but that actually doesn't matter. While drum tests don't do well at predicting tire rolling resistance on varying road services, they do an excellent job at comparing rolling resistance between tires. In other words, if tire A rolls better on drum than tire B, then tire A will also roll better on a paved road than tire B. There will always be variations and exceptions, but this general rule of drum testing being good at determining relative differences between tires has been re-confirmed many times.

So, when choosing between different tires, drum testing may not be able to tell you exactly what the rolling resistances of each will be on the pavement you ride on, but it will be able to tell you which will roll better than the other on the pavement you ride on.

Think of it like this: Say you had to select between two otherwise very similar bikes to climb a variety of long, steep hills. When you put the bikes on a scale, one weighs 15 lb. more than the other. Just from the weight data, you can't determine how long it will actually take you to climb each hill - but its a very good bet that you'll climb each hill faster on the lighter bike.

[Calnago]

I don’t know that I agree with the above post. Here’s why... on a cylindrical drum, the tire doesn’t even get a chance to “spread out” like it would on a flat surface. It will squash out along just the very tangential surface where the two circles (tire and drum) meet. Versus if the tire we’re allowed to spread out on a flat surface (real road), I think the two total surface areas in contact with each other at any given time would be very different. Thus, the tire that is more supple might be able to squash out relatively more on the flat surface, increasing friction, and hence rolling resistance. So, a nice supple tubular for example might indeed have more rolling resistance than a less supple clincher but because of the better contact with the pavement it would likely be a better handling tire as well. Tradeoffs. Always tradeoffs.

[David Benson]

the tire that is more supple might be able to squash out relatively more on the flat surface, increasing friction, and hence rolling resistance.

Respectfully, you are misunderstanding the mechanism that causes rolling resistance.
The roller test is a measure of the energy required to deform the casing as it rolls into the contact patch.
You can find wordy, and maybe tendentious, arguments as to whether a roller test produces results that are truly comparable over a wide range of tyre section and casing flexibility, however, wherever you stand on those arguments, the internal friction in the tyre casing is the cause of the rolling resistance measured.

[Calnago]

Thanks, and I’m willing to learn more, but I’m not there yet from your explanation. What do you mean by “internal friction”? Where does the external friction between the tire and the road (or the rollers) come into play. If you’re talking about the measure of friction within the rollers somewhere, it really has no idea how much surface area contact there is between the tire and the surface, does it? Would not a bicycle “treadmill” produce much more realistic surface to tire friction numbers.
Assume for example, the the rollers were made of see through glass. Now, with the same pressure exerted on a tire (say about 200lbs for a bruiser like me), there would be a visible contact patch where the tire meets the roller and if you could stop that roller at any given point you could measure the area of that contact patch. I suspect the area for two different tires, one supple and one not so supple, might still be fairly close to each other simply because of the the two round shapes trying to squeeze against each other, versus two flat shapes being sandwiched together with full contact. But if the same thing was done on say, a flexible glass treadmill (if there were such a thing) that contact area might be larger for the supple tire than the stiff tire. I’m talking more than just in the same proportion as on the rollers and hence the difference. I’m saying the difference in the areas would be greater on the flat surface than the difference in the areas on the two round surfaces meeting each other. And if the area is larger, so must be the friction with the same given weight pushing down on it.
Does that makes sense. I’m not saying I’m correct for sure, but that’s my intuition and it is something I’ve thought about before but it’s just not big enough of a bother to worry about. Still, I am curious and since I’m visiting here and saw this thread I just thought I’d throw the thought out there. Thanks for any further insights you might have to help me understand why it doesn’t make a difference where friction results are measured between a tire rolling against a drum versus on a flat treadmill.

[EDS]

How hard are the GP5000s to mount?

[dddd]

I could see that perhaps different tires would respond a bit differently to a flat surface vs. a curved surface, and perhaps near in proportion to the change in the length of the contact patch. But do different tires built for a common type of use employ much difference in their bias angle and thickness for this to matter?

Where rough vs. smooth-surface rolling resistance shows big differences between tires is when tire size (with appropriate pressure) changes. With a larger/softer tire, the mass that moves (and whose motion energy is then damped) is largely localized to a small portion of the tire/tube itself, versus the entire tire, wheel and front end of the bike that must move (and be damped) when the tire is more unyielding.

So with these racing tires, assuming all same-sized tires, the rolling resistance differences we are comparing should have little to do with the roughness of the road.
But a test to compare flat versus curved-surface rolling resistance of a batch of tires would be a good thing to include with one's data table comparing lots of tires that have been tested on a roller.

[dddd]

How hard are the GP5000s to mount?

That's going to depend more on the rim, and to whether or not the tire has been in use or at least inflated for a while.

Tire beads that have some dust on them slide more easily along the length of the rim bed, so that working slack can be pulled out of the tire with less force.
A tire lubricant does this even better.
A thin and slippery rim tape would seem likely to help greatly as well.

[bikinchris]

How hard are the GP5000s to mount?

I have only mounted a regular (not tubeless) set on a Mavic rim and they fit very well. When I mount a new set of tires, I usually talcum powder inside the tire and the new tube, but I was a long way from my talc, so they went on dry so to speak. No problem.

[bismo37]

Anecdotally... I rode Conti GP4000 for years. Then switched to Vittoria Corsas and Paves for a few years. They rode better and felt grippier, particularly on wet sloppy roads. Since Vittoria switched to graphene and then lost ISO Grip tread, 360TPI and stopped making the Pave version, I lost interest in them and switched some bikes back to GP4000SII. Well, dang it if the Continentals don't feel noticeably faster. I will likely be trying out the GP5000 when I need new tires.

[David Benson]

Thanks, and I’m willing to learn more, but I’m not there yet from your explanation. What do you mean by “internal friction”?

For 'internal friction', read 'energy required to deform the casing at the contact patch'.
Energy lost due to molecules of tyre stuff bumping into each other.

Where does the external friction between the tire and the road (or the rollers) come into play.

I think that, travelling in a straight line, friction between the tread and road surface is probably negligible.

Assume for example, the the rollers were made of see through glass. Now, with the same pressure exerted on a tire (say about 200lbs for a bruiser like me), there would be a visible contact patch where the tire meets the roller and if you could stop that roller at any given point you could measure the area of that contact patch. I suspect the area for two different tires, one supple and one not so supple, might still be fairly close to each other simply because of the the two round shapes trying to squeeze against each other, versus two flat shapes being sandwiched together with full contact. But if the same thing was done on say, a flexible glass treadmill (if there were such a thing) that contact area might be larger for the supple tire than the stiff tire. I’m talking more than just in the same proportion as on the rollers and hence the difference. I’m saying the difference in the areas would be greater on the flat surface than the difference in the areas on the two round surfaces meeting each other. And if the area is larger, so must be the friction with the same given weight pushing down on it. ...
Thanks for any further insights you might have to help me understand why it doesn’t make a difference where friction results are measured between a tire rolling against a drum versus on a flat treadmill.

Contact patch area is determined by load (ie bike & rider weight), tyre pressure, and casing stiffness. The contact patch area will be the same whether the test is on a a roller or flat treadmill, however the shape of the contact patch will be different.

Jan Heine has written an article about why he considers testing on a flat surface is superior to using a drum, but his argument also boils down to energy loss from casing flexion rather than contact patch area:
https://janheine.wordpress.com/2018/05/02/testing-tires-isnt-easy/

[Keith A]

That's going to depend more on the rim, and to whether or not the tire has been in use or at least inflated for a while.

Tire beads that have some dust on them slide more easily along the length of the rim bed, so that working slack can be pulled out of the tire with less force.
A tire lubricant does this even better.
A thin and slippery rim tape would seem likely to help greatly as well.Tire lubricant? Never heard of such a thing, but I'm interested in finding out more about this.

[BikeNY]

Tire lubricant? Never heard of such a thing, but I'm interested in finding out more about this.

There's a product called Bead Slip or something like that. Or do as MTB riders have been doing for years with tubeless tires, a bit of soapy water.

[Keith A]

There's a product called Bead Slip or something like that. Or do as MTB riders have been doing for years with tubeless tires, a bit of soapy water.Thanks. I've used the soapy water trick and it does help on those extra tight tires.

[BikeNY]

Yes, but that actually doesn't matter. While drum tests don't do well at predicting tire rolling resistance on varying road services, they do an excellent job at comparing rolling resistance between tires. In other words, if tire A rolls better on drum than tire B, then tire A will also roll better on a paved road than tire B. There will always be variations and exceptions, but this general rule of drum testing being good at determining relative differences between tires has been re-confirmed many times.

So, when choosing between different tires, drum testing may not be able to tell you exactly what the rolling resistances of each will be on the pavement you ride on, but it will be able to tell you which will roll better than the other on the pavement you ride on.

Think of it like this: Say you had to select between two otherwise very similar bikes to climb a variety of long, steep hills. When you put the bikes on a scale, one weighs 15 lb. more than the other. Just from the weight data, you can't determine how long it will actually take you to climb each hill - but its a very good bet that you'll climb each hill faster on the lighter bike.

I can maybe believe that if comparing same size tires for use on very smooth roads, but other than that, I think these tests are meaningless. Different tires react differently to a smooth steel drum than they would to a paved road with lots if regularities. Also, a round drum is pushing further into the tire than a flat surface would, causing threads and such to compress more than they would in normal use, and perhaps more than they were designed to.

[GregL]

I can maybe believe that if comparing same size tires for use on very smooth roads, but other than that, I think these tests are meaningless. Different tires react differently to a smooth steel drum than they would to a paved road with lots if regularities. Also, a round drum is pushing further into the tire than a flat surface would, causing threads and such to compress more than they would in normal use, and perhaps more than they were designed to.
Respectfully, you missed Mark's point. The drum tests give accurate, relative ranking of tire rolling resistance. The tires will in fact have different performance in the "real world," but their performances relative to each other will remain the same.

Greg

[BikeNY]

Respectfully, you missed Mark's point. The drum tests give accurate, relative ranking of tire rolling resistance. The tires will in fact have different performance in the "real world," but their performances relative to each other will remain the same.

Greg

I didn't miss his point at all. I'm saying that for same size tires that relative ranking might be true, but when comparing different size and construction tires, the relative rankings will not be accurate.

[Mark McM]

I didn't miss his point at all. I'm saying that for same size tires that relative ranking might be true, but when comparing different size and construction tires, the relative rankings will not be accurate.

And yet: No doubt you've heard that wider tires have lower rolling resistance than (otherwise similar) narrower tires. This result has been duplicated not only on rollers of varying diameter, but also on (flat) pavement. The is true for differences in tire construction as well..

Interest in tire rolling resistance is not unique to bicycles. With requirements and regulations for increased automotive fuel mileage, auto and truck tire rolling resistance has become of increasing importance. Tire and vehicle manufacturers are keenly interested in using the lowest rolling resistance tires (and there's a lot more money riding on it). What system and equipment do they use to measure and compare tire rolling resistance? They roll the tires against metal drums. Here's one such test machine:

https://www.polinggroup.com/testing_end_rrt-tb.php

https://www.polinggroup.com/im/p/rrt-tb.jpg

[yinzerniner]

Huh? I don't understand what you are getting at here. I didn't make any comparisons between tests, just pointed out the results of each test. It sounds like you're the one jumping to conclusions here. It's like you're grasping at straws just to maintain your narrative of, "you're wrong!".

What you wrote a few posts before:
In this test, the GP5000TL did slightly better than the GP5000 with latex - but only by about 1% (vs. the GP5000 being 4.5% better in the Aero Coach test). Possibly the differences were in test conditions, or perhaps manufacturing batch variations in manufacturing the tires. In any case, it appears the data is pointing toward the GP5000 with latex being as good as, or a little better, than the GP5000TL.

If THAT statement isn't a comparison between tests, then I don't know what is. You stated that one test shows a small difference to result A, while another shows a larger difference towards result B, and you're siding with result B even though the testing methodologies and results figures for those tests are completely different.

I stand by my assessment that your conclusions are based off of faulty methodology for my statements provided earlier, which one might label as "grasping at straws" while another might label as "submission of evidence." I myself am awaiting the inevitable test done by BRR on the latex vs butyl vs tubeless, for as you stated earlier:
"this general rule of drum testing being good at determining relative differences between tires has been re-confirmed many times."

See, something we can agree on!
:banana:

[mtechnica]

I didn't miss his point at all. I'm saying that for same size tires that relative ranking might be true, but when comparing different size and construction tires, the relative rankings will not be accurate.

Incorrect

[dddd]

I didn't miss his point at all. I'm saying that for same size tires that relative ranking might be true, but when comparing different size and construction tires, the relative rankings will not be accurate.

It shouldn't matter much if tires at least similar in size are being compared, but I don't see the point of comparing much-different size tires, inevitably run at very different pressure.

The softer tire will show improvement (relative to a smaller, harder tire) as the surface becomes rougher, since the softer tire won't lose as much energy to wheel/bike mass motion being damped.

The drum could be used to compare the bigger tires to other similarly-sized tires, or perhaps as an indicator of how wider tires compare to narrower tires on smooth roads, but then the question would arise as to what pressure would be used in each.

I'm confident that the testers are aware of the effects of the drum's finite radius, and have made it big enough to nullify most of the effect of said radius versus a flat surface. For comparative purposes it should be fine.

[benb]

Did it come in #1 again on the "Still feels like a garden hose taped to the rim" test?

Haha! This!

Every time I try Contis they're really hard to mount, feel horrible, don't inspire confidence in cornering, seem to get more flats, etc...

But the positive in it is they wear out fast so I can get back to tires I like!

Weird thing, I'm sure some people like them, we're all different, but they don't work for me.

I have been really happy with Specialized's faster options the last few years. They work for me. Pretty much 0 flats, do well in the tests, good feel, confidence inspiring in any weather... even kept me upright on dirt & mud when it was unavoidable. The ones I've been riding have been the S-Works Turbo which is not the cotton one. I might be giving up 3-5W vs the fastest tires.

[Mark McM]

What you wrote a few posts before:


If THAT statement isn't a comparison between tests, then I don't know what is. You stated that one test shows a small difference to result A, while another shows a larger difference towards result B, and you're siding with result B even though the testing methodologies and results figures for those tests are completely different.

Again, you're exaggerating in an attempt to prove your point. I'm not "siding" with either test. I merely made the observation that from these two tests it appears that the GP5000+latex rolled similarly to the G5000TL, and that one test showed a more favorable result toward one GP5000+latex than the other test was unfavorable toward it. I have no idea how a reasonable person could object to that observation.

As far as comparing different tests to each other: It is true that variations in the tests could result in variations in results. But if the tests are well controlled, the variations should be small. As we've also been discussing in this thread, drum testing produces useful information for comparison of tire rolling resistance on actual (flat) roads. So why shouldn't two drum tests provide useful information in comparison to each other?* The entire tire industry believes they should, and have re-confirmed this relevancy since drum tire testing began (almost a century ago). If you don't believe that the rolling resistances from two drum tests can be compared, then you must not believe that the results of drum tests can be compared to rolling resistances on the road. In which case you must believe that all the drum tests done over the many years on a wide variety of different types of tires are completely worthless.

**While it is true that one of the drum tests on the GP5000/TL reported results in power, and the other reported results in Crr, that doesn't mean that they have no relevance to each. Afterall, power and Crr are proportional to each other (P = Crr x N x V).

[Mark McM]

I can maybe believe that if comparing same size tires for use on very smooth roads, but other than that, I think these tests are meaningless. Different tires react differently to a smooth steel drum than they would to a paved road with lots if regularities. Also, a round drum is pushing further into the tire than a flat surface would, causing threads and such to compress more than they would in normal use, and perhaps more than they were designed to.

None of these concerns are new. Using drum tests for tire rolling resistance testing has been done since the 1920s. Various methods have been developed to compensate and correct for issues such as those you mention. Drum testing has been found to be a quite reliable method to estimate rolling resistance on pavement. There's enough information on this on the web that a quick google search should provide lots of information on how drum tests are performed, and why this method is preferred.

[Jere]

Thanks. I've used the soapy water trick and it does help on those extra tight tires.


If you do not like Soapy water try Windex the old blue stuff.
It’s and old motorcycle tire trick I used when changing 650c for little friend.
JB

[Rusty Luggs]

Interesting that the test results cited by the OP shows reduction in rolling resistance with INCREASING pressure.....

[GregL]

Interesting thread. Rolling resistance is obviously important, but not the only determining factor for a "fast" tire. There is lots of tire testing information out there, but putting it all together in a cogent manner is often challenging. The fastest tire is the one with the right combination of low rolling resistance and low aerodynamic drag on the wheel under test. If a tire with low rolling resistance is an aerodynamically poor match for the wheel it is mounted on, it may end up being slower than expected. Tire inflation pressure also plays a large part in minimizing required input power. In short, it's the tire/wheel/inflation pressure combination that will determine what is optimum for speed. Now add reliability/resistance to punctures and the elusive "road feel" to the decision making matrix.

I like to have a fast tire/wheel combo, but I'm not going to over-analyze this. Pick what makes you happy and ride on!

Greg

[benb]

Interesting thread. Rolling resistance is obviously important, but not the only determining factor for a "fast" tire. There is lots of tire testing information out there, but putting it all together in a cogent manner is often challenging. The fastest tire is the one with the right combination of low rolling resistance and low aerodynamic drag on the wheel under test.


To many of these threads act like we ride in perfectly straight lines on flat ground in perfect weather.

These variables can be meaningless as soon as you throw in some curves and descents and such.. if tire A has less rolling resistance and tire B gives more confidence cornering/braking tire B can end up being a lot faster in the real world. Poor cornering erases a ton of speed. Anyone can see these.. we're here debating < 10W or even 5W at probably 30mph but anyone with a PM has seem there average/normalized power for an interval plummet by quite a bit more than that just going through one tight corner at speed. If one tire lets you dive into that corner harder and gives you confidence to pedal deeper into the corner, pick up the power sooner, or gives you confidence to pedal all the way through the corner that's worth a lot.

This stuff is all probably near meaningless anywhere except a TT with a specific type of course profile with an elite athlete riding the bike. All the tires keep getting faster but the differences between brand A and brand B are not that big, and it's not like anyone is debating about running a 1985 tire vs a 2019 tire.

Feel of speed is great fun but so is feeling good in the corners & in the rain.

[AngryScientist]

i'll be doing some of my own testing in the spring.

classically, i have really disliked conti tires due to sidewall reliability issues i've experienced, and generally dont like the way they "feel", especially compared to vittoria or veloflex.

anyway, you can read about a tire all week on the internet or you can just buy a pair and give them a try and see for yourself. that's what i intend to do.

additional datapoint: on a 23mm rim, these 25c tires measure out to 24mm inflated to 85 pounds.

https://instagram.fewr1-1.fna.fbcdn.net/vp/d7b8efc2180ad4690d6069303fea994b/5CD1217A/t51.2885-15/e35/47693186_1097430527103003_6887730600347674122_n.jp g?_nc_ht=instagram.fewr1-1.fna.fbcdn.net

[Mark McM]

additional datapoint: on a 23mm rim, these 25c tires measure out to 24mm inflated to 85 pounds.

Is that 23mm internal rim width? If not, do you know what the internal width is?

[AngryScientist]

Is that 23mm internal rim width? If not, do you know what the internal width is?

no, 23mm external. i dont know the internal width offhand. i can measure though this weekend.

[Mark McM]

no, 23mm external. i dont know the internal width offhand. i can measure though this weekend.

Thanks. I've been considering the GP5000 for a bike I have with HED Jet wheels (21mm internal width), but the frame only has clearance for tires that are a maximum of 26mm wide. 700x25c GP4000S tires expand to 28mm on this rim, and so won't fit, but I'm hoping the GP5000s will fit.

[yinzerniner]

Thanks. I've been considering the GP5000 for a bike I have with HED Jet wheels (21mm internal width), but the frame only has clearance for tires that are a maximum of 26mm wide. 700x25c GP4000S tires expand to 28mm on this rim, and so won't fit, but I'm hoping the GP5000s will fit.

Based off of others' observations for 17c rims the GP5ks are just about true to size, give or take .5mm either way due to rim design variation. If you're using 21c rims the 25mm GP5ks will probably be 27mm wide as the 28mm GP5ks fit to 29.2mm on a 19.5mm ID Easton Rim (made by HED).

https://www.bentrideronline.com/messageboard/showthread.php?t=143342

If you're OK with running clincher then maybe the 23mm GP5ks will be the best bet.

[Davist]

So, from my riding buddy who has 5ks in 25mm: "My 5K contis on my zipp 454 measure 26m at 90PSI"


17mm internal per zipp.

My Chinese Zipp clones, also 17 with 4k 28s measure 33mm


Per above, looks like the 5ks are true-er to size on rims now. Good news.

[biker72]

Quote from bicyclerollingresistance.com:
Size. Surprise: the 25-622 version of the GP 5000 measures 26 mm wide and 24 mm high at an air pressure of 100 psi / 6.9 bars on a 17C rim. This is a surprise because all previous 25-622 Continental Grand Prix tires with the 3/330 casing measured 27 mm wide on my rim.


I'm pretty sure Continental adjusted the size of the casings with the release of the GP 5000 as it makes sense with the popularity of wider rims these days. It also explains the lower specified weight of the GP 5000 range of tires. Be aware that the 28-622 GP 5000 is 25 grams lighter than the equivalent rated GP 4000 and might possibly be 2 mm smaller.

[Cloozoe]

I've thoroughly enjoyed the battle of the Brads and as such this seems almost off topic, but...

Early in the thread some seemingly defensive Conti aficionados said, in effect, "you can have your "supple" Vittorias; I'll ride past you and wave while you're fixing your flat."

But RR rates the Vittoria Corsa G+ slightly more puncture resistant on both tread and sidewalls. Is he wrong?

[tuscanyswe]

I've thoroughly enjoyed the battle of the Brads and as such this seems almost off topic, but...

Early in the thread some seemingly defensive Conti aficionados said, in effect, "you can have your "supple" Vittorias; I'll ride past you and wave while you're fixing your flat."

But RR rates the Vittoria Corsa G+ slightly more puncture resistant on both tread and sidewalls. Is he wrong?

Yes that is wrong! :)

Vittorias are rubbish in this regard, imo.

[simonov]

Yes that is wrong! :)

Vittorias are rubbish in this regard, imo.

Ditto. Vittoria G+ ride nice enough, though I wasn't blown away by them, but they aren't nearly as durable as claimed. Like not by a country mile. Like I had to toss the rear after 200 miles bad.