Kapusta

What is to address? Where are these tests? He is stating something, but I am not seeing any of the data. Most importantly, I don't know what type of tires or roads he is talking about. How does he even test the RR on the road?

Sorry, but I am not taking someones word for this.

Why am I skeptical? My first inclination that something was off was when they gave the Compass Bon Jon Pass (among the fasted tires I have run) a pretty slow score. This made no sense to me and is definitely not my experience. Further, as I looked around to compare to other tires I have owned, I found they gave a very similar scores to the Bon Jon and the Marathon Supreme. I have owed both of these tires, and there is no way in hell they are anywhere close to each other in rolling resistance. The Bon Jon was WAY faster. Night and day difference. Heck they rated the Gatorskin (which I have also owned) only slightly slower, and that is a freaking garden hose compared the Bon Jon Pass.

I think the problem with the roller drum test is that it deforms to tire differently than a flat surface does. Is deforms the casing under in the middle or the tire (under the tread) more sharply than a flat surface does. This means it gives more weight to the flexibility of that part of the tire casing than a flat surface does.

Now, maybe that does not matter for many tires, if they are of similar construction. But what if you have a tire that is especially flexible in the sidewall both rather thick under the tread (Like most compass/RH tires)? I think what is happening is that the thick tread slows it down more on the roller drum than it would on a flat surface (a real road).

So until I see some evidence (not just someone saying it is so) that the roller drum tests are a reliable predictor of rolling resistance on real world surfaces for a wide variety of tire constructions, I am taking them with a big grain of salt. Are the results correlated? I am sure they are, but that can fall apart with individual tires that have unusual characteristics.