Excellent test, thank you for providing the link and many thanks to Aerocoach for testing !

An addition to this test, you can also look at my friend’s Alban rolling resistance results : http://www.cyclesetforme.fr/...-gp-5000-et-5000-tl/

It’s great that Continental managed to improve on an already excellent every day tire that’s also great for racing when we want to play it a bit safe in term of puncture protection ! Good job Conti ;-)

Wow, and bike closet has them for 54.99 right now. Might have to splurge on a couple. Good to see some actual data.

Nice test and thanks for the link. Looks like the 5000s are a nice upgrade from the 4000s. I have used the 4000s as my everyday tire for years, so it is nice to have a simple upgrade.

It looks like the ultimate TT tire is still going to be application dependent because the aero advantage is too small at low yaw and Crr isn't good enough to match the more fragile SS and Corsa Speeds.

Thanks for sharing. Based on those results, the GP 5000 will likely become my new "go-to" tire. IMO, the very minor total wattage penalty it sees to the GP TT is offset by its markedly increased puncture protection.

Edit: interesting, the French site has the tubeless GP 5000 tire outperforming the clincher GP 5000 with a latex tube. Not by much but I still find that interesting.

Thanks for sharing. While I am all for data I would have preferred to see this test done with:

1) a deep front wheel of some sort, preferably a wider one
2) as a wheel only test

Interesting that the GP5000 was also narrower but tested worse at low yaw than the wider GP4000.

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That's very disappointing.

In 6-12 months, basically the whole world is going to be rolling around on tyres that are significantly faster than the (currently near-ubiquitous) 4000 SIIs and those of us that actually pay attention to these things and are already running quicker tyres will have lost a little bit of our advantage :(

 
Interesting, thanks for the link

Seems to be in line with initial claim (12 % better RR than GP4000s2), as they are measured here exactly at 12% gain in RR vs GP4000s2 ...
bringing it around same results as GP Attack/Force and Michelin Power Comp for rolling resistance. But less fragile ?

Waiting for BRR test to confirm RR (not a lot of suspense...), and their puncture test :-) as I do not try to picture my own tires voluntarily...

Don't worry, I'm sure Conti and others will issue more efficient and fragile tires, you will be able to continue to take puncture risk for a few watts ;-)

Very nice data, this is gonna be a cash cow for 10+years for continental no doubt.
Any data on the puncture resistance yet?

yes, the GP TT is a popular tire.

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

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Agreed

I don't see any good reason why you would choose to put a rider on the bike when testing the front wheel aerodynamics.
All it does is add massive potential for error.
I'd also like to see a deep section wheel as you say. The aerodynamic data is going to be relatively unimportant to anyone using a shallow box section rim. It would be more useful to test with a more representative deep rim, ideally with a 19mm+internal width as that will still provide the RR data for all, but also more useful aero data for those interested.

They did test with a wide rim - 19.6 internal ID. I suspect it's the same box-section rim that forms their Aeox deep wheels, since it also has the same outer ID.

However, since wheels like FLO were designed specifically to match the GP4000s, and the Aeox to match the Corsa Speed, I guess that's a pretty decent rationale for choosing a "neutral" rim. If compared to a deep rim, they should've gone for some no-name Chinese rim that sure as hell wasn't "optimised" for anything.

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ZONE3 - We Last Longer

I know they used a wide rim. I was saying they could still have achieved this with a deeper rim and lost nothing on the rolling resistance testing. Aerodynamics cannot be dismantled piecemeal. You can't neutrally test a tyre. I think I know what you and they mean about avoiding unfair advantages due to optimised pairings but it's not really a sensible argument for choosing a box section rim IMO. That too will favour one over another, though unintentionally. Any deep section wheel whether optimised or not is more representative than this. A tyre cannot exist on a bike in isolation. There is always a rim. The aerodynamics cannot be simplified to just the tyre. Best option is to test the tyre with a few different appropriate rims. If testing aerodynamic efficiency, then more aerodynamically efficient rims are appropriate. If you can only test one, pick a popular one and if there's any specific optimisation claimed, state it. Simple as that.

What does 12% improvement in rolling resistance mean in real world for your average MOP rider?

Edit - I do see the chart they posted, claiming 4 watts @ 45km/hr. So maybe more like 2 watts at 35km/hr....

I'm thinking good opportunity to stock up on sale GP4000IIS's..... :)

agreed....all im reading is while its an improvement on the 4000s in both RR and aero, it still falls short overall to the less aero gp TT, purely on RR alone.

On real roads, a bit more watts, corresponding approximately 90 to 120 seconds on a IM70.3 90km bike course.

Really?!! I save 2 min in a HIM over the 4ks2? That’s a lot!

And one more minute if you go GP TT.
At around 33/35 km/h average.
Using same inner tube, of course.

At higher speed, gain is a bit smaller, but when you are a pro, it can be worthy.

Why do you think pro take the risk to get a flat running fragile tires and fragile inner tube ?

They are different tires though. I think a better test would be the 5000 TL setup tubeless vs the 5000 TL w/ latex tube.

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Why?
Obviously the same tyre with a tube will be higher RR than without!
There's no need for the test you suggest.

GreenPlease's comparison is between the sensible tubeless and tubed options as they are intended.
If you intended to use a tube there's no reason to get the tubeless version which will presumably have more, or different material, and/or a different bead to ensure air retention.

Look at TomA's testing. A corsa speed setup tubeless tested no faster than with a latex tube. They were exactly the same.

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So based on their testing, is the 23mm version the best size for modern wide rims like HED and Flo?

And their testing, it was with the -tubed- version, right??

Cheers

I hadn't seen that. Presumably this is due to the sealant? Did Tom ever suggest an explanation?
Were the difference solely tube or no tube I would have a very hard time believing such a result was not down to experimental error.

I'd speculate that it's just that the losses from a latex tube are so small they can't be measured with the precision of the tools used.

Any scientific testing includes certain assumptions and limitations - they chose theirs. I agree it would be more appropriate to test any kind of deep-section rim (even a 50mm road-focused rim).

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ZONE3 - We Last Longer

I realise that. I've done my share. But I think they chose very badly both by using a rider and using box sections. Thus my comment.

Of course. If I had a dollar for every time I disagreed with an author's methods, I'd be able to publish in predatory journals...

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ZONE3 - We Last Longer

Actually, no. IME, testing road tires with a latex tube results in the same Crr as with it set up tubeless.

That's the reason I don't bother testing them set up as tubeless.

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http://bikeblather.blogspot.com/

Which is exactly my point.....

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The latex tube is in there, just in liquid form…

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Eric Reid AeroFit | Instagram Portfolio
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I'm not sure if I understand your point then. You are saying above that a test of the TL tire with and without a latex tube in it is somehow better than comparing the clincher w/latex vs. the TL?

The former doesn't give you much new info (i.e. they will test ~ the same), the latter tells you if you gain anything running the non-TL w/latex vs. the TL.

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http://bikeblather.blogspot.com/

I took a look at these results and I'm mind blown by the width/height difference between the 4000sii and 5000. I can't fit a 25mm 4000sii on my NP3 on wide rims (enve 7.8) . Now I'm debating if the 25m 5000 will fit, since it's much less wide and high...

Yes, the 5000, not the 5000TL. They do not specify tube type. But specify 90 PSI.

Front wheel : 23mm better for aero I guess. Plus 25mm does not work on my P3
Rear wheel : being a bit heavy (170lb) I will stick with 25mm on rear wheel, i think RR gain (at 115 PSI) will largely overcome slight aero loss, and is more comfortable

I’m not willing to give up puncture resistance for a minute. Over 20 races and I still have yet to get a flat with the 4ks2’s. I’ve had 2 flats in training in 5 years.

+1

Used GP4000S2 this year
Was planning Michelin Power Comp for next year. But GP5000 is looking good. Waiting for puncture tests :-)

I don’t need a test. Can’t be worse than the 4ks2’s. They already said it’s better.

Funny.

I am actually totally fine with their rim choice. I think it was Cycling Weekly that did a windtunnel test using the 25mm Michelin on something like 10 different aero wheels. That's a nice tire, but nobody designs for it. There were some really odd results that I can only attribute to the tire being different from the shape used to design the rim (e.g., the Rovals were absolutely terrible. Worse than some open mold rims). At least the box section rim indicates differences in the profile of the tire as the leading edge of an airfoil and whether the texture encourages flow attachment out to higher yaw angles.

This is "early" data but do you have any speculation as to how the tubeless tire with a butyl liner manages to perform on par with the regular clincher with a latex tube?

If you look at this test: http://www.cyclesetforme.fr/...-gp-5000-et-5000-tl/

...you'll see that he standardized at 6 bar and that the 25mm 5000 tl actually measured nearly 1mm narrower than the 25mm clincher... so if anything casing tension should have biased the test in favor of the clincher. The same goes for the RS tire which measured a full 3mm wider. I'm not sure how repeatable this tester's setup is but it sure seems like he's making a decent stab at it. His comment of switching from latex to butyl adding "10watts on the rollers and 2watts in the real world" is a bit strange...

It would not shock me if Continental took the approach of focusing improvements of the 5k on rolling resistance and weight. Then simply make claims on durability and puncture resistance that are on par or better than the 4kS2. Weight is super easy for anyone to confirm. Rolling resistance is going to get independently tested by multiple sources. But puncture resistance is highly anecdotal. For every person that says they get 2-3 flats per year on their 4k tires, there is another person that says they never got one in 5 years.

Overall, the 4k tires get good reviews on general puncture resistance due to the thousands of anecdotal responses from users...not really because Continental says it's good. So I don't think we'll really know if we'll know for sure about this for a while. And even if they puncture resistance on the 5k tires are 50% worse in reality, will anyone really notice the difference. That person who was getting 2-4 flats per year may now get 3-5 flats per year. That person who never got a flat in 5 years may now get 1 in 5 years.

I would love for it to be true that Continental lowered rolling resistance, lowered weight, maintained or slightly improved aero, and maintained or slightly improved puncture resistance. I'm just not going to hold my breath at this point.

I’m sure it can be tested somehow.
But what other test can be be better than empirical observation. 1 puncture every so often plus 20+ races of no flats is a strong evidence of some puncture resistance.

I get where you are coming from Tom. You make a valid point that the original test may be better. But I'm merely trying to point out that a tubeless tire setup tubeless is NOT any faster than with a latex tire in it. Your corsa speed test proved that but there are countless people out there that still think a tubeless tire is faster. Mostly due to the marketing of TLR wheels and tires.

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Rolling resistance will be tested seriously by independent sources
Aero also
Weight is easy to check

AND

Puncture resistance will be seriously tested also by at least one independent source (tread and lateral)
Durability can be easily tested by thousands of user

Finally, the only one parameter not seriously tested (to my knowledge) will be grip

Perhaps it's not a butyl liner? I don't recall Conti saying...

Best I can tell, he's using even smaller diameter rollers than I do, so that 2W to 10W "amplification" could make sense.

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http://bikeblather.blogspot.com/

Multiple press releases had it as a butyl liner. Whatever they're using, initial reports seem promising.

What I'm wondering is why do they even make a non tubeless version.

Because tubeless + inner tube will be heavier and less performing than standard + inner tube.
Not even sure tubeless alone will be better than standard + latex inner tube (apart maybe self healing capability from sealant). This comparison will be interesting, because up to now, from the serious comparison I've seen, the tubeless do not win. But it will come. Will it come with GP5000 ? May be.

But for sure tubeless + inner tube better than standard + inner.... no

And non-tubeless is ... mmmm... more than 90% of the market.

Why make a competitive product for 90% of the market... instead of a non-competitive product.... mmmm ,,,, wondering....

From what I see the tubeless tyre with latex tube is 2 watts faster. not calculating.,how hilly a course has to be to make it slower than the non tubeless due to weight, but I imagine it will be a lot of hills required

I would imagine that for most the heavier tubeless with latex tube will be faster.
I guess the reason they make the non tubeless is purely for the reason that conti believes most people are to stupid or lazy to use latex tubes ( they might have a point there but still it's not performance in my mind it's more an "Ignorance" tyre)
I don't think many people have complained that vitoria speed is only avaialbe in tubeless version.

I guess I'm coming from this point as I never use the 4000 as for me it's to slow for racing and to expensive for training.

Do not know where you find these 2 watts.

On the french site the guy (Alban Lorenzini) test "5000TL alone" vs "5000 + latex" and find 0,3w difference at 30km/h (calculated from roller measurement processed), probably less than the margin error for this test process (roller and 6 bars pressure - quite low).

So, as I say, "5000TL alone" might be slightly better than "5000 + latex", or not, but I will wait for more precise test on big drums to say.

And for sure, if you add an inner tube to the 5000TL, it won't help.

Thanks for this second link. Interesting also.

Similar results for "5000TL alone" and "5000 + latex".

Alban says in the comments that his recommended config is :
5000 + Latex for rear wheel
5000 + Butyl front wheel

due to similar perf with a "5000 TL alone" x2 config, and much better repairing possibilities with the 5000, compared to 5000TL.

What are the much better repairing possibilities? Does the TL not accept a boot as well or something? And why butyl in the front?

I will not translate the complete exchange in french between Alban and the other guy, but to make a long story short :
- they both feel manipulation of tubeless is a pain in the ass
- butyl in front for heat protection on braking : latex too fragile to support high temperature variations due to intense braking, so not good on front wheel

et maintenant, dodo

Huh. Thanks for the translation.

Not IME.

Since Conti do not even make latex tubes, they clearly do not believe in them full stop. Heck, consumers cannot even buy their tubs with latex inners, which are reserved exclusively for pro/semi-pro teams.

Hello

this quote is a traduction of what Alban say in some comments/discussion with another guy (en francais dans le texte).

Personally, I only used latex inner tube on track : little braking involved. So, no experience on the road.

But I heard many times (including from road pro) that latex inner tube are considered dangerous on carbon wheels if heavy braking is involved.

Then, of course, "heavy braking experience" can be different if you tri on a relatively flat course or if you repeat up/down alpine and pyrenean pass.

Doing both, I do not use latex on the road. I mean... for inner tube.

 
Another comment made by Alban (en francais dans le texte) is that installing the GP5000TL was very difficult first time, a bit easier second time.

And he was sure that trying to install it with an inner tube (at least for 23mm and 25mm, might be easier for 28mm, TBC) will most probably lead to the inner tube destruction.

So, it appear using GP5000TL with inner tube, compared with GP5000 + same inner tube :
1) will be much heavier
2) will most probably lead to worse Crr (but still to be measured)
3) is nearly impossible to install on a rim... well you can try, but it will cost a lot in inner tube

The answer to the question : "why a standard version ?" is now clear.

May be the question should be : "why a tubeless version ?" as tubeless is a very small part of the market, and apparently still a bit crappy techno.
Answer is probably : as a market leader, better be early in a niche market which could develop, even if now most people still don't care about it.

I confirm the tubeless hassle but still prefer it because it will seal in case of puncture, that trump any hassle. When i train for that big race i don't want to think about eventual puncture.
I'm actually riding Corsas TLRs and with sealant they're a reliable option. From time to time i have a puncture and finish the ride between 3-4bars which is barely noticeable in term of rolling resistance on such a good tire.

Never an issue here either. Raced on the tremblant course about 12 times now, latex front and rear, with full carbon clinchers, and with HED Jets, never a single flat, no issues. I train mostly indoors, but in the outdoor riding I've done over the past 5+ years, I've used latex, not a single flat tire. (knock on wood). I've used both the red vittoria latex tubes, and the Vredestein latex tubes.

Tubeless road wheels and tires have been around since at least....what....2004 (specifically remember the dura ace pre-builts back then)? Gotta be a reason why after 15 years, most people still don't want to deal with them.

Most people also don't use latex tubes. I'm a diehard member of the Effing Road Tubeless Mafia (FRTM). I will smugly ask, "Need anything?" as I roll by you on the side of the road.

The most challenging braking I do is racing down 10mi of switchbacks, slamming on the brakes before each turn. The latex tubes have been fine for that.

Zipp did a braking heat test, and found that their rim strip would fail before the latex tube. But there are other reasons why latex could be an issue with carbon rims and extreme braking. The rim and tire bead become softer when they get hot, and latex is not as good at retaining the tire.

>90% of the flats I get are sidewall cuts, and tubeless wouldn't help. Small sharp things like goatheads, staples, tire wires, etc will rarely puncture the latex tube if I stop and pull them out. Bigger things that puncture the tube are unlikely to be fixed by sealant.

Not my experience.

That’s great for you. My experiment with road tubeless resulted in a cut that wouldn’t seal, so I gave up and threw a tube in. I love the promises; the reality leaves something to be desired for some use cases.

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The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

Yeah, but if the sealant doesn't work . . . good luck getting a tube in that thing!

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Dimond Bikes Superfan

Not the whole world.

It seems shorter riders are being left behind, Instead of 700 & 650C it looks like Conti are only making 650B GP5000s.

Im hoping that’s only a short term situation.

Agreed. We are riding all kinds of nasty off road tubeless and it’s all good.

I’ve been tubeless road for two years now without difficulty. Actually the only flats I’ve had have been butyl tubes with small wire/stick. Off road and on road tubeless are fine. My tubeless tire is easier to mount than my Michelin tubed tires

 
From Alban tests, GP5000 TL are much more difficult to install than the GP5000.

Regarding the Michelin tires, I had also difficulties (Power Endurance), until a guy in a LBS show me how to do, now I do that very easily.

Bicycle Rolling Resistance just posted their test results for GP5000. Rolling resistance was measured as being comparable to the GPTT and significantly lower than the GP4000. Puncture resistance using their test protocol is a little better than the GPTT but not as good as the GP4000. I have been using 23mm GPTTs, but given these results I may make the switch to 23mm GP5000s based upon the GP5000s smaller size and potentially better aerodynamics.

They obviously believe in them enough to put them in those Pro LTD tubs ;) their sponsored teams get. My guess is it's a cost exercise. Not enough sales to warrant manufacturing them and more cost effective to chuck in their own buttel inner tubes in their tubs.

Of course, this is just after I bought a new set of GPTTs. Might use them on the rear with a GP5000 on the front...

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ZONE3 - We Last Longer

I also have a pair of unused GPTTs and am thinking of doing the exact same thing. GP5000 on the front for improved aero and GPTT on the back because it will roll at least as fast as a GP5000.

So based on their results, looks like it is roughly 2 watts faster than a 4000?
So the very general rule of thumb that 10 watts = 1second/km...
The 5000 will be roughly 36 seconds faster over an Ironman, but have slightly lower puncture resistance.

Seems like a good reason to stick with 4000's and grab some good sale prices.... :)

Double all that for two wheels.

Updated data for the 25c tubeless and clincher versions of the GP 5000: https://www.aero-coach.co.uk/gp-5000-tubeless-data

On modern wide rims like Flo and HED, do 25mm tires balloon out too much and lose watts to aerodynamics?

Caveat to that data which I just learned on Twitter...all of the Crr tests are done at 90 psi. According to my own calcs, based on the measured widths, if the 23C was run at 90 psi, then the 25Cs should be inflated to 80 psi to get the same "Berto 15% drop".

In other words, the Crr for the larger tires won't be as low "in the real world" as compared to the 23C as reported...and might tilt the overall demand results more in favor of the narrower tires...just sayin'...

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http://bikeblather.blogspot.com/

Sorta kinda, just looking at Tom A's one test.

The 24mm Turbo Cotton kinda sucked (at aero) on the HED Jet 6+ compared to its 22mm SW Turbo sibling on the same wheel. Of course that's just one wheel and one tire.

And there is other anecdotal stuff I've read here that suggests that ~23mm tires are the sweet spot for the front wheel on modern rims if you're going for every last bit of Cd. I think someone here (GreenPlease?) even pitches like 20mm tires on the HED Jet+, but, I, personally, would not attempt that.

I've always though the interesting thing about the below is that the classic narrow H3 with 19mm tires does not win at low yaw (excepting watts-to-spin and Crr, blah blah)

I believe you’re right about this coming from GreenPlease, but I think this is in reference to the latest 20c GP SS which with the new casing measures up more like a 23c tire.

I have been racing on this combo. The 20c SS measures exactly 25mm when mounted on a jet + rim, and looks perfect from an aero perspective.

How hard is it to get that tire on the HED Jet+ compared to a GP4000?

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What's your CdA?

easily done with hands, though a little tougher than a 25c 4000 (haven't mounted a 23c 4000 in awhile so can't speak to that).

So I was all excited about building up a road bike out of a cross frame for the 33c TL version of this tire. Was pretty sure I was going to go with the ENVE 4.5 AR disc wheelset, but just noticed they say this tire isn't compatible? Anybody know what's up with that?

No bead hook on the ENVE?

EDIT- Confirmed. Continental recommends against hookless rim designs for this tire.

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"They're made of latex, not nitroglycerin"

yes known... but what is special or unspecial about the 5000TL that it cant work like a Pro-One from Schwalbe can ?

Dunno, this is straight from the ENVE website...

Bummer

i think the best result can be
GP TT rear, 25mm
GP 5000 front, 23mm

Weird. I assumed all TLR rims were hookless these days.

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Any run that doesn't include pooping in someone's front yard is a win.

+1

Rear wheel I usually have 25mm around 115 psi (I'm 170 lb / 77kg)
Front wheel, either :
25mm 100 psi (road bike), as less weight on front wheel, and need for some grip
23mm 110 or 115 psi (P3 tri bike, 25mm don't fit, not enough clearance, and better aero with my rims size)

not a problem, 23mm 110/115 psi is around same resistance as 25mm 100 psi, as confirmed by BRR tests on GP4000s2, or other tests.

What internal rim width? Those psi are...excessvely high

Edit: typo

I'm thinking this may be the way too. I have been using gpTT 25 on both wheels, which are super fat Aeolus, 27mm wide at the brake track. It seems a 25mm gp5000 on the front may be the way to roll now.

Hello

Internal rim width : 15 (road aluminum) or 17mm (55mm carbon)

Found these rec. for road 25mm tires :
70 kg : 7,5 bars
80 kg : 8 bars

I'm 77kg, so go for 7,8 bars (113 psi) for rear wheel

Front wheel, remove 10 to 15% if 25mm. If go down to 23mm, in this case same pressure than rear 25mm wheel.

Globally remove 10% or 20% if wet (for grip).

This is coherent with discussions I had with most elite or pro using similar tires (with weigh adaptation, of course). And I'm used to ride on far than perfect road.

in front TT tire is not good because it is flat thread so not good for air flow. you need some thread, thats why gp4k or gp5k front

Disappointed they are not making a 24mm. I wonder if the 25mm will fit any better on my P2 than the 4000!?!?

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"The first virtue in a soldier is endurance of fatigue; courage is only the second virtue."
- Napoleon Bonaparte

yes, but the RR more than made up for it. With the gp5000 the gap of RR has seemed to have decreased significantly

I'm heavier than you, usually 80-82kg for races but above 85kg at the moment :(
For my road bike I use 23mm with 85-95psi at the front and 100-105psi at the back without any problems. I often ride on very bad roads and I'm using 15mm internal rims. In summer I switch to 25mm (23mm is needed for clearance from mudguards in winter) and with these I drop to about 75-85psi front and 85-90psi rear on the same rims.
On the tri bike I've got 19mm internal rims and I use 25mm with 70-80psi on the front and 80-90psi rear.

Bad roads make lower pressures desirable IMO, especially on the front when riding a tri bike on the extensions without your arms providing the same shock absorbing duties they do on the road bike. Last time I got a pinch puncture was hitting a raised edge on a drain about 6 years ago so I'm certainly not running too soft for reliability. I do like the front at the mid to upper end of those ranges if I'll be sprinting or climbing on the road bike, just to avoid an excessively squishy feel.

Thinking it may be time to upgrade the race wheels to these tires, I appreciate the lower rolling resistance but I'm also a fan of the greater puncture protection. Hopefully the hype will die down and they will come down in price soon.

Really, marketed sizes have almost become irrelevant as measured sizes are almost always different....although rarely smaller on a road tire so your point is taken.

Michelin suggest pressure between 6 and 8 bars on the road.
6 bars (approx 87 psi) for 50kg rider
8 bars (approx 116 psi) for 80 kg or higher

at 77kg, running my rear wheel on the dry between 110 and 113 is OK for me depending on road quality.
Alu training wheels are comfortable, and do the job.
Racing, generally better road quality, feel OK with carbon race wheels (55mm).

Rec. from Continental for GP4000S2 :
23mm : 110 psi (7,6 bars) - max 120
25mm : 95 psi (6,5 bars) - max 120

I suppose this is for average weight rider : 70kg ?

Considering at 77kg (+10%) I'm in the high range, adding 10% to 95 psi, and running 105 psi (for 25mm rear wheel) make sense for me (Ok I'm slightly above).

Again, when wet, go down to 90/100 PSI (F/R, when both 25mm).

Thanks. I think a lot of P2 owners on this forum will attest than a Conti 4000 larger than a 23 does not fit well on that bike (depending on the year) and may rub. I'm running 25's on mine, but it required liberal screw adjustment in the rear dropouts and is still pretty tight. Was just thinking a 24 might be a good compromise. At the end of the day, I guess I should be using 23s, but greatly prefer the 25s.

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"The first virtue in a soldier is endurance of fatigue; courage is only the second virtue."
- Napoleon Bonaparte

On my P3 (2014) :

no problem to run 25mm GP4000s2 on rear wheel
front wheel, 25mm GP4000s2 leave not enough clearance (1 or 2mm only), but I did it anyway. After few hundreds km, the tire slightly change shape, and was rubbing on down tube.

Even if GP5000 is announced 1mm less in height (BRR measurement), I will go for 23mm for front wheel !

Early accounts are that the 5000's fill out a bit smaller than the same nominally sized 4000SII. For all intents and purposes, a 25c 5000 seems to fit like a 24c 4000SII would have, if such a thing ever existed.

continental-grand-prix-4000s-ii-2014-vs-continental-grand-prix-5000-2018 (scroll to "Size and Weight Measurements" )


I was planning to order a set of 5000's, but the 4000SIIs are down to $30 (25's and 28's, anyway; didn't check 23's) with free Prime shipping on Amazon. For my non-race bike, the performance difference isn't enough to pay another ~$50/pair.

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"They're made of latex, not nitroglycerin"

In terms of comfort I'm inclined to go lower than that. There's no need for pressures that high. As I mentioned, I'm heavier and ride a lot of very poor roads yet I don't suffer pinch punctures. Beyond that it's about performance, where a compromise between comfort and rolling resistance is probably justified in long distance racing but comfort wins out in training. Do you know if they give any rationale for those recommended pressures or are they simply bouncing back what people tell them they use? Do they even break down the recommended pressures by tyre sizes, rider weight, bike type, or road quality?

For now. Since this is largely a new tread compound, I imagine they'll be rolling that compound out across the line over the next year or so.

Nope...for road/gravel use that Enve rim is a bit of a "unicorn"...and not necessarily in a good way due to its equipment restrictions

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http://bikeblather.blogspot.com/

So is hookless really an MTB thing? All my other TLR rims are for CX/MTB.

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Any run that doesn't include pooping in someone's front yard is a win.

Pretty much...and its only real purpose is to make carbon rims easier to manufacture.

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http://bikeblather.blogspot.com/

Yep, I've come to the conclusion that lower pressures are not only better for training, but also for racing.

Sure there's a small increase in rolling resistance, but you're not loosing momentum (or dropping a chain) bouncing all over the place.

Plus it also allows you to keep the power down over really bumpy stuff & corner with far more confidence.

At ~80kg I'm now running 80/75 on 25mm GPTTs. That's still a decent (pinch flat) margin over ENVE's tubeless ~67psi recommendation.

^^^^
Awesomeness. I'll try the 5000 25's out this spring.

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This does not make sense. Why would you use the tire with much less puncture resistance on the wheel with far greater chance of puncturing? According to the tests done so far, there is a negligible difference in rolling resistance between the gp tt and the gp 5000 ( .1 watt?)- So what is the advantage of greatly increasing your chance of puncturing on the rear wheel?

Keep in mind that the sizing of the GP4000 was off. A 23 mm Conti measured the same as a 25 mm gatorskin. So a 23 mm 4000 was really the size of a 25mm
The GP 5000 were corrected for this. So your 25 mm 5000 will be very close to the 23 mm 4000 :-)

Lower hookless rim lips are less prone to rock strike and damage.
Also less likely to cut the tyre when pinched in hard landings.

I have never had issues with punctures with the tt- plus it seems the 5000 isn’t all that much better

I just do not understand any reason to choose the TT over the 5000. The CRRs are virtually the same, .1 - .3 watts difference in favor of TT, but they were not tested at the same time and this difference is well within margin of test error, and if you tested 10 tires of each there would likely be significant overlap of which is “faster”. While the TT puncture resistance is clearly enough for you, and most riders, the 5000 is in fact much better- by more than 20% by BRR tests, and more than 30% by Conti’s tests. Further tests have shown them to be extremely close on CdA and CRR combined, but the CdA is pretty much a non factor on the rear. The amount of miles you will expect on the tire is about double on the 5000 over the TT, so the cost per mile about 1/2 (BTW- you can get a 5000 today for about $ 45 at http://www.bike-discount.de).
So exactly what is the reasoning to buy the TT over the 5000? 20 grams of weight?

Roval, I9, Boyd and Alto are among a few others that make hookless rims, along with most car and motorcycle wheels. A bead hook is either typically molded in or machined off, the latter of which can weaken fibers. Without the hook a rim can be stronger and have different interaction with tire bead for better shape.

it depends who's testing your looking at. Aerocoach says the RR is far better on the TT than what Tom says. 7 watts@ 45kmhr. Aero wise, it loses 1.7 watts.
Im not saying who is right or wrong for anyone. But i have a few TT tires here already, im not going to worry about putting a 5000 on the rear until the TT atleast wears out.

Ah, then it makes sense that everything is hookless hookless hookless in the MTB/CX world. I guess triathletes don't worry as much and rims holding up to five foot drops.

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Any run that doesn't include pooping in someone's front yard is a win.

I must admit I am hopeless at deciphering the results of the CRR testing.

At the moment I have 23mm Conti SuperSonics on Zipp 808 FC (front and rear) running latex tubes. I was using them for the last two seasons and they are up for a replacement. Up until now I was thinking about picking Conti GP TT next, 23mm for the front (aero) and 25mm for the rear (added comfort)

would the new GP5000 make a better replacement? Should I pick 23mm or 25mm ?

It appears the GP5000 RR is much closer to the TT but the TT is still better (difference varies depending on which testing you look at). Assuming the GP5000 has an aerodynamic advanatge up front which mitigates any small difference in RR, it may be the better choice since you'll get a more durable tyre with little or no cost and maybe even an advantage depending on the balance of RR and aero drag differences. At the back it's more debatable IMO. If it's very close on RR then the GP5000 may be the best choice purely for increased durability. Or, perhaps you stick with TT since the aerodynamic differences are less relevant. If the differences are very small, I'd go with GP5000 for both. If they're bigger, it may be worth considering TT, especially at the back. It may depend on which test data you trust more!

i think, atleast this time around, the contis actually come up close to spec. EG, the 25 Tom tested was 26 in width. I would choose that for your zipps.

My bontragers are 27mm, so 28's would prob blow up too wide. 25 should be about right for me too, although they would probably mate to a firecrest a bit better.

Thanks.

I should have added that the Zipp 808 FC I have are the older kind (pre-2015), so a bit narrower and (as far as I rememeber) optimized around 23mm tires.

Right...so it makes carbon rim manufacturing easier and stronger (like I said), but doesn't exactly improve the security of the tire/rim interface...or else there wouldn't be the restrictions on what tires are allowed, no?

I'll need more objective data on the "better shape" claim before judging that ;-)

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http://bikeblather.blogspot.com/

Hi

Just got this today
$112.00 for two and latex tube’s

https://www.merlincycles.com/...mp;mc_eid=58cf00b7ac

Oh, i'm in that club... I haven't changed a flat on any of my bikes in over 3 years. Why.... tubeless.

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I am not sure if I missed this or not but could someone chime in please - I run the Enve 7.8 wheelset and historically ran a set of 4000II 25mm width - If i want to run the GP5000 would I need to now go with the 28mm width to achieve the same 27mm that the GP4000 gave (or is this not known yet).

It is a shame that they are not recommended to run Tubeless

EDIT: I just read on Rolling resistance that the casing seems to match measured size;



So if this is correct than the 28mm @ 100psi should equal in the 27mm range (which I run 100psi)

Enve 7.8 are tubeless compatible according to their website.

Sean,

It was mentioned earlier in this thread that Enve does not recommend the GP5000 in tubless format for the rims due to the hookless design :(

The 4.5 AR disc are the only enve road wheels that are hookless. You’re good to go with your 7.8s.

Thanks, I missed that!

Well that throws another hitch in the equation!

I guess for me it comes down to which one performs better overall now (waiting for BRR). The size questions still stands though - i'm thinking the GP5000 28mm are the old GP4000 25mm in terms of shape/size.

My GP5000 25mm measured at ~26.8mm when mounted on a rim that was 27.5mm wide with a 19mm internal width. The GP5000 28mm on that same rim was just shy of 29.5mm. Both inflated to 95 psi.

Interesting - thank you for getting that information!

I wonder if it would line up with the Enve rim being so wide. I have been on the struggle bus all day and need to quit skimming things as I misread not only this post with the Enve rims but what BRR stated about the tire width...

Regarding the size difference between the 4000 and 5000:

I just took the 23 mm GP4000s off of my wheels (Giant SLR 0 Aero 55s). They measured approximately 25.50 mm in width fully inflated
.
I replaced them 25 mm GP5000s. The new ones measure approximately 25.70 mm. Just 0.20 mm larger.

They really did shrink them. The new 25s are the old 23s. Glad I didn't buy the 23 mm new ones.

 
Interesting, thanks.

Also use Giant SLR0 aero 55mm on the P3.
Did you also make measurement for heigh ?

The 25mm GP4000 was not fitting on the front wheel with my P3 (rubbing on frame after 300km), was going to go 23mm, but if they shrink, may be not ?

I did not check the difference in height, I admit. I have to think it can't be that much. It seems to me that the new GP5000 25 is just a marginally larger GP4000 23 with lower rolling resistance

How old were your GP4000S tyres? They stretch over time. In my experience they grow at least one mm in width over time.

I've stopped using the GP4000s II tyres, as I had a few too many sidewall cuts with those tyres. I've probably binned four or five tyres due to sidewall cuts. Some cuts were too big too repair safely with a patch. Strangely enough, the old GP Attack and Force 22+24 mm have more durable sidewalls (in my experience), but I get a few more 'standard' penetration punctures. Sidewall cuts are terrible if you're running latex tubes like I do. While stiffer butyl tube sometiems work, the latex tubes peek through the sidewall holes and get punctured straight away.

I've always had issue with the side wall pealing on conti tires. Both for commuting tires and when my gf was running some of the first hot chilli tires. Has this issue been address with conti tires?
I'm a big fan of Vittoria tires - good price, ride nicely, not a lot of punctures. Can anybody comment on performance of the GP5000s vs vittoria tires?

bicyclerollingresistance.com, unbiased reviews of most popular tires. Very detailed, including puncture tests, sidewall, complete weight and measurements, and, of course rolling resistance. All Vittorias and Continentals are on the list, and he has a great comparison tool

I just got them last year. Never heard anything about them stretching over time though. That would have been noticeable on my bike since the clearance in the rear is so tight that larger tires rub on the chainstay.

Gp4000s have always been very good to me. Incredibly tough

<replying to thread in general>

Anyone have or have seen measured width data on the 28 & 33c versions of these? preferably on wide rims like enve? tubeless or non?

GP4000 s2 stretched on my front wheel. I had initially 2mm clearance, and 300km after, it was rubbing on the frame.

Too bad they use butyl tubes in all the tests

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And they don't test all available widths of tires.

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blog

It's a good resource, but I'm a little skeptical of the accuracy and precision of the way he measures force on the tire and power to spin it.

But it also provide comparison for GP4000s2 between :
butyl
butyl light
latex

Actually the accuracy and precision are very high. How directly it applies to riding on a asphalt road surface is a fair question. It certainly provides an accurate and objective comparison of the tires, as they are all tested in highly repeatable conditions with high accuracy.

And it provide comparison for GP4000s2 for 23mm, 25mm and 28mm

Can you explain why you believe that is the case?

Are you sure that's the tire and not the wheel?

Sure, you can question whether the absolute .crr values he comes up with are correct and/or relevant to riding on asphalt or concrete. When you look at the rankings and relative differences between different tires, though, his results generally jibe with others who've tested the same tires.

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"They're made of latex, not nitroglycerin"

Yep

Because I removed the rubbing tyre (of course) and installed another one (GP Attack 22mm), and now the clearance is constant (and larger), so wheel is perfect. And new tyre also.

The GP4000s2 stretched a bit in one place only, probably slightly more than 1mm.
Not an issue, really, I will reuse it on back wheel.
But no more 25mm on the P3 front wheel.

Based on his published testing protocols and, as others have noted, the consistency of his numbers when compared to other testing sources.
Can you explain why you are skeptical of his accuracy? If your issue is the relevance of the numbers to real world use on asphalt roads, I understand your point, but there is no practical way to resolve this as there are infinite variations in hardness and textures of road surfaces.
IMO this data is much more useful than cdr numbers for bike frames, or any component that is part of a much greater system and is tested on it’s own.

I'm not concerned about mimicking asphalt. The apparatus that holds the wheel has a sliding fit with one tube inside another (friction). I'm not sure how the load is applied, but as I recall that was not a simple weight, but rather a load cell of some kind. And measuring motor input and subtracting an efficiency is not the best way to determine power. There are too many opportunities for random errors and a drift in calibration.

The "consistency of numbers compared to other sources" argument doesn't hold weight. Errors big enough to be obvious in that respect would need to be pretty huge. Since he is testing and comparing tires over a span of years, I'd like to know if he gets the same results with the same tires over that span. For instance does the GP4000 measured now have the same Crr as 4 years ago?

That would be nice, but how do you propose he preserve the tire over a 4 year period from environmental changes? Bottom line, I trust his testing and have had good results picking tires from his data. If you are looking for absolute verified perfection, good luck :-) BTW- he has many results posted on his site of the same tire used in multiple tests, you can certainly review those and decide if it meets your standards. If not, and if you have a better source for more reliable tire data, I would greatly appreciate you sharing, as would many other on ST

If he has Tire A as 8% higher .crr than Tire B, which is 5% higher than Tire C which is 7% higher than Tire D, and then you see another tester come up with the same order and very similar relative differences, and then a third, you don't think that gives some validation to his methods?

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"They're made of latex, not nitroglycerin"

 
I agree with gary p and IntenseOne that BRR is making very accurate evaluations of tires, both for dimensioning, puncture resistance and rolling resistance.

Did not found better source in the web.

Of course the margin error can be discussed, but from comparison with others tests, it appear margin error is lower than differences between most tyres.

And I'm not worried about this margin error, because, anyway, when hitting real road, Crr will significantly change, and possibly differently for different tyres and different types of roads...
... plus, the impedance effect will also reverse the lower sides of the Crr/pressure curve, differently based on weight, road, speed, ...

So, real life Crr will be very different, and is much more multi-parameter and complex than the curve given by BRR.
BRR possible margin error is far from being significant then...

IMO, BRR curves are an excellent basis. Not perfect, but really good enough as a first evaluation.

Then you have to make your OWN evaluation for :
1) butyl, light butyl, latex (BRR supply good evaluation for these differences)
2) tyre size (BRR also supply good evaluation for these differences) - taking into account bike clearances
3) optimal pressure (most complex parameter because of impedance "reverse curve" effect depending on pressure, but also road, tyre, speed, ...)

From my personal experience, real life rolling resistance measured are up to 2,3 times BRR figures, on "not good" asphalt.

Show me.

The reason I questioned his setup in the first place (many years ago) was because his numbers did not match other sources. The apparatus is inherently susceptible to error, particularly over time. If there isn't a way accurately calibrate it, and no attempt is made to quantify the degree of error... then it's hard to have faith in the results.

RR just published its results on the TL GP5000 - pretty awesome!

very nice indeed. Link to results =>

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Looks like the TL GP5000 is basically the same as the standard GP5000 with a latex tube.

(assuming the ~2w latex delta is similar to the GP4000 tests).

That is what I am coming up with - I think I am trying tubless for the first time ever this season based on the various results we have seen!