Tubeless Tyres -"saying the same things about tubeless tyres over and over again" Hippy read the first f**king post

Works well if you leave the inner tube in.

Then you need to sort out why it wont seat as you don’t want to be doing that shit at the side of the road

Repped

Once it's seated, it should stay there.

you need to sort out why it wont seat as you don’t want to be doing that shit at the side of the road

Not an issue. If your puncture doesn't seal with goop or anchovy, you're going to be inserting a tube to get you home.

You can run a lever under the bead, moving it into place, to seat some or all of it. This achieves something similar to the inner-tube trick in my experience - and you don't have to mess around with the valve

Thanks, I did, it has sealed 🙏

Riding is always the answer!

I'm taking it for a proper ride tomorrow so will report back on the tyres. The learning from yesterday evening was 80psi is too much in them for a sub-62kg weakling like me.

I thought the fit with inner tube method had been debunked ages ago

Being 350tpi Italian 'open tubular' tubeless tyres these arrive flat as a pancake, so they need to sit on the wheels pumped up hard with a tube in for a bit anyway to become tyre-shaped.

But given pumping up hard with a tube locks the bead on one side, meaning you only have one side to worry about, I don't get why you wouldn't do it?

Because you simply don’t need to with a tyre that’s already round. Totally agree that it makes sense with this specific tyre though.

Is there a verdict on GP5k yet? Pondering 32c

@Fox any feedback on them yet?

Running them in 32 and like them. Smooth ride and fast/grippy as ever.

They're basically Gp4000 28 with a bit less tread thickness, yeah? So faster at the expense of durability/punc protection.

at the expense of durability/punc protection.

I imagine the R&D department will have been aiming for longer life and more puncture protection (they actually claim the latter) by modification of the compound and processing of both the tread band and breaker since the Gp4000S2

Yeah, but did that actually happen?

"benefit of the newly improved Vectran Breaker layer, the polymer which forms a multi-strand thread and acts as a blockade against foreign objects such as thorns, glass or flint. This is said to be improved by 20 per cent in the new GP 5000"

"Our tests confirm rolling resistance of the GP 5000 is actually even lower with a maximum of 18% less rolling resistance at the highest air pressure of 120 psi / 8.3 bars! At the lower air pressure of 80 psi / 5.5 bars, there is indeed 12% less rolling resistance according to our tests."

"Unfortunately, our tests indicate that puncture resistance of the GP 5000 has gone down when compared to the GP 4000"

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

These guys actually do a comparison: https://www.bicyclerollingresistance.com/road-bike-reviews/compare/continental-grand-prix-4000s-ii-2014-vs-continental-grand-prix-5000-2018

I don't know how they do their puncture tests but that tallies with what I said - they're a couple of watts faster but not as puncture resistant. Has anyone done a long term test for durability?

Also comparing a tubeless tire vs non tubeless has got to make direct puncture resistance more difficult

There is a normal GP5000 though. So that comparison should be the same.

I don't know how they do their puncture tests

Hammer and nail, then adjusted by tread thickness. It's only one point difference, and they don't show the spread of numbers for the multiple test points to give an indication of the error bars. 10 vs. 11 could be 10.4±2 vs. 10.6±2 🙂

"The puncture resistance test is performed with a 1 mm steel needle to which weight can be added.
The needle gets positioned at the center of the tread for the tread puncture test and on the sidewall for the sidewall puncture tests. More weight gets added until it punctures the tire.
The puncture test is performed 5 times for both the tread and sidewall. We then take the average of these 5 punctures and calculate this to a puncture force score in points. A score of 10 in the puncture force test means it takes twice as much force to puncture when compared to a score of 5.

Puncture Factor
Puncture Factor is calculated by multiplying the puncture force from the puncture test by the measured tire thickness. Just like the force required to puncture a tire, the thickness of the tread and sidewalls is also very important to prevent punctures in real-life.
What we've found is that casing material and anti-puncture strips take a lot of force to puncture. The rubber, on the other hand, doesn't take much force to puncture as it's a very soft material. We found that a tire without an anti-puncture strip but that does have a thick layer of rubber doesn't take a very large force to puncture. In reality, it does offer a lot of puncture protection because the thick layer of rubber simply doesn't allow the object to reach the inner tube."

Yeah, so now I need someone like skinny to run them to their death like I would and let me know how they compare with 4000S. I know Matt F didn't have much luck with them in last year's TCR whereas I was golden on my Pro 4 Endurance but they're substantially tougher than 4000S and eventually met their match with speed + rocks in Spain.

I've had tubeless set up on my cross bike for the past couple of years without any troubles, but suddenly a set of Schwalbe x-ones that have been installed fine for the past few months have begun to leak at one point on the rim and won't seal.

I can't see any damage to the tyre and I'm beginning to suspect I've damaged the rim? Is there anything else I should check? Damaging the rim seems slightly unlikely because although I regularly smash them into hard things, I haven't done so recently and the leak is a new problem.

@ewanmac - have they simply become quite loose on the rim? An extra layer of tape has resolved this issue for me.

You may have pinched the tires just where it meets the rim. Or the rim tape may have somehow moved and the air is leaking under. The valve may be full of gunk and not closing fully.
Just fill something with water and find the offending leak, mark it and investigate

Humph... definitely a (pretty minor) dent in the rim. I can get it to seal fine in my garden but just about to take it for a spin around my village to see if riding causes it to leak again. If I survive the village then I’ll be straight out on a 3 hour loop in the Cotswolds... I can’t imagine that anything could possibly go wrong.

You can get the dent out with a spanner and a flat piece of steel if it's causing issues.