New Continental 5000S Tires - Tubeless Compatible

[AJS914]

Is there much benefit of going road tubeless if one hardly ever gets flats? I've had one flat in the last three years (GP4000s).

[Mr.Gib]

Is there much benefit of going road tubeless if one hardly ever gets flats? I've had one flat in the last three years (GP4000s).

Nope, just more weight, cost, less choice, and more work if you need to change tires. It's all about avoiding punctures. I won't run tubeless in the summer and I won't ride without tubeless in the winter.

[TobinHatesYou]

Is there much benefit of going road tubeless if one hardly ever gets flats? I've had one flat in the last three years (GP4000s).

Rolling efficiency and being able to run lower pressures than regular clinchers.

One puncture in three years is a bit extreme.

If you're running tubeless, you won't even notice the next puncture you get three years from now until after the ride.

[bm0p700f]

More comfortable and more grip with tubeless.

[bm0p700f]

Marin,

The IRC rbcc tyre has higher rolling resistance than the conti by a few watts but I think there was more sealant in the test I had done so the result is not comparable. Even with 20ml sealant the rbcc tyre is not as quick rolling. Its not a test artifact.

The IRC rbcc tyres though don't slice as easily and have more grip. The conti's feel quicker. So there a trade off. There might be a wear rate difference too.

Jarno puts 20ml of sealant in the tyre which is not enough. I normally shove 40ml min, in the the tyre. That's adds a few watts by itself.

[Marin]

Thanks!

[aeroisnteverything]

Jarno's test use a 42.5kg load at 28.8km/h. The difference between a Fusion Galactik and GP5K TL at 80psi is about 2.4W. x2 for two tires.

So let's assume a real world condition of a 85kg system weight up an 8% grade at 14.4km/h. The rolling efficiency will be roughly halved...so back down to around 2.4W total. So it's 2.4W vs 150g.

With bikecalculator an 85kg rider+bike going 14.4km/h up 8% is pushing 313W. An 85.15kg rider+bike pushing 315.4W is going 14.46km/h. You might lose more during accelerations and such, but it's so close even at low speeds that the weight savings doesn't overcome the better rolling efficiency. Now add flat ground and the obvious winner is the GP5K TL.

Have done the math also for a lighter rider (68 kg, with bike base weight of 8kg). Works out that Conti is better than Hutchison at all speeds and grades. Scenarios chosen are somewhat personalised, but nevermind that:
- holding 250 watts on conti up 10% grade on hoods gives 10.66 kmh, vs 10.65 kmh on Hutchison at corresponding wattage/weight
- same up 5% grade: 18.27kmh on conti vs 18.18 kmh for Hutchison
- on flat, at 200 watts and in the drops: 34.49 kmh for conti vs 34.03 kmh for Hutchison

The thing of course is that this speed differences are pretty tiny - until you get to flat road. And even on flat road, there is likely a bigger difference between the two tyres in aero performance (both tyre shape itself and how it interacts with the wheel that it sits on). Which one is better in the aggregate? Most likely Conti, but margins are slim and unless one spends $$$$$ on your specific bike, with your specific wheels, testing little variations in the wind tunnel - going to be hard to tell. But given the data at hand, and since Conti is also superior in puncture protection, the choice seems pretty clear.

[Marin]

It's sad that physics is killing our weight obsession. I'm suffering massive cognitive dissonance because I'm about to order 32mm GP5000 Tubeless - at 380g per tire. That's MTB tire weight FFS!!!!!

[aeroisnteverything]

It's sad that physics is killing our weight obsession. I'm suffering massive cognitive dissonance because I'm about to order 32mm GP5000 Tubeless - at 380g per tire. That's MTB tire weight FFS!!!!!

At that width, you are also probably killing your wheels aero performance though....

[zefs]

Thing is as the tire wears you loose rolling resistance, but the overall lighter tire will always be lighter. Might not be worth considering in this case but it would be interesting to see how wear affects rolling resistance in a test.

[Marin]

At that width, you are also probably killing your wheels aero performance though....

It's a "fast touring" bike with aluminum rims...

[Marin]

Thing is as the tire wears you loose rolling resistance, but the overall lighter tire will always be lighter. Might not be worth considering in this case but it would be interesting to see how wear affects rolling resistance in a test.

Tom Anhalt had a test that showed that tires get faster as they wear IIRC

[zefs]

Thing is as the tire wears you loose rolling resistance, but the overall lighter tire will always be lighter. Might not be worth considering in this case but it would be interesting to see how wear affects rolling resistance in a test.

Tom Anhalt had a test that showed that tires get faster as they wear IIRC

Rolling resistance is based on the tire compound which decreases heat generation, so when it wears there would be more heat so it could make the tire faster in that sense so probably right I guess. I thought it was the opposite.

[morrisond]

Has anyone measured a 32mm Tubeless or Tubed yet?

[RocketRacing]

I thought there was a bike rolling resistance article on how old ires are slower...