Challenge Criterium RS

[LanceLegstrong]

They are right about one thing: the only correct color for these tires is white, and they are beautiful.

[TobinHatesYou]

Wet grip is still a problem with the new compound, but everything else looks quite good.

And BRR’s scale does not adequately enumerate how bad the wet grip is on Challenge tires. They are downright dangerous.

[Yoln]

Wet grip is still a problem with the new compound, but everything else looks quite good.

And BRR’s scale does not adequately enumerate how bad the wet grip is on Challenge tires. They are downright dangerous.

Care to elaborate?

[LanceLegstrong]

Anybody with a membership care to post the rolling resistance vs psi chart? Looks like less than a watt compared to GP5Ks at 100psi. Curious to see them at lower psi.

[Yoln]

Basically identical RR to Michel Power Cup, and .7 to .9W higher than GP5k depending on the version at 80psi

[LanceLegstrong]

Not bad at all. Thanks.

[TobinHatesYou]

Care to elaborate?

There’s nothing elaborate about my comment. They have no wet grip in a practical riding sense.

[RDY]

Depends on the road surface. On slick asphalt, yeah, they're lethal. But IMO no more so than similar tires. I.E. I've found the GK Slicks just as bad as Strada Bianca HTLR on smooth asphalt. On rougher tarmac they're certainly not class leading, but not dangerous either.

But the amount of time I ride on smooth asphalt, is very small, and smooth wet asphalt is close to nil.

Anyway once available in larger sizes, these should be my tire of choice for dry weather given the excellent RR at 60psi, and good puncture protection. Challenge say end of year / early next for the bigger sizes. I'd guess there will be a 30 and 33 if they conform to sizing in other tires.

[TobinHatesYou]

Depends on the road surface. On slick asphalt, yeah, they're lethal. But IMO no more so than similar tires. I.E. I've found the GK Slicks just as bad as Strada Bianca HTLR on smooth asphalt. On rougher tarmac they're certainly not class leading, but not dangerous either.

But the amount of time I ride on smooth asphalt, is very small, and smooth wet asphalt is close to nil.

Anyway once available in larger sizes, these should be my tire of choice for dry weather given the excellent RR at 60psi, and good puncture protection. Challenge say end of year / early next for the bigger sizes. I'd guess there will be a 30 and 33 if they conform to sizing in other tires.

Not my experience at all. With 40mm Strada Bianca Pros I went down instantly (slid out both tires) while taking a slow corner at about 25km/h with barely a lean and no brakes. Everyone else in my group made it around with no issues on regular narrow road bike tires. The road was damp and the surface was standard asphalt/bitumen.

Check the comment section here: https://www.bicyclerollingresistance.co ... r#comments

[RDY]

Fat slicks are going to be much worse than narrow slicks in greasy or wet conditions. They aquaplane much more readily. That's what's happening when they slide.

[Miller]

Fat slicks are going to be much worse than narrow slicks in greasy or wet conditions. They aquaplane much more readily. That's what's happening when they slide.

We do not ever experience aquaplaning with bicycle tyres, our tyre pressures are too high and our speeds are too low. Assuming THY was running say 60psi, and using an equation given in wikipedia, he'd need to be travelling at 80mph/130kph before aquaplaning could occur.

So no aquaplaning and that's just physics (lol).

[Lina]

I'd like to see any bicycle tire aquaplaning at 25 km/h. Reality is that it just doesn't happen at those speeds. Even on a full slick. Losing traction on wet doesn't mean that the tire is aquaplaning. It's aquaplaning when it can't displace all the standing water between the road surface and tire so that the tire is no longer in contact with the road.

[RDY]

Ok, I'm using the term incorrectly. But adhesion is going to be minimal in wet, especially on a compound that has poor wet adhesion, so you're relying on deformation. If your tire pressure is just a little bit too much than the (wet) conditions demand on a fatter tire, then you're going to go down as they won't deform enough to grip. Even at too high pressure a narrow tire will still deform quite significantly at the contact patch, even if area of contact is small. My experience was that you had to run big GK Slicks and SBs way below normal pressure in the wet on smooth surfaces. If the surface is smooth it significantly reduces the deformation. I expect other fat slicks wouldn't be hugely better, unless they deform a lot more. I haven't found a similar need to run narrower slicks way below dry pressure in the wet even if their adhesive properties are better.

[mathias720]

i have been running the michelin powercup tlr untill now for road racing, but really looking forward to trying these as they seem to have way bette puncture protection, same rolling resistance, and a bit wider thread.
i really dont race in wet coniditions anyway.

[ViperFFM]

At this point I wonder if there ever will be a better tyre than the 5000 TL that Conti discontiniued because it was too good