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According to Bicyclerollingresistance.com, the fairly slick and 34mm wide Panaracer Gravel King has a rolling resistance of 20.8 W whereas the decidedly knobbly and 53 mm wide Continental Race King Protection comes in at 20.2 W. I've ridden the latter and I would find it hard to believe that a skinnier tyre feels faster.

Now I understand that the material alone can make some difference. But I feel I'm missing something along the lines of "Rolling resistance is in function of the tyre width", or "Rolling resistance is just one thing holding you back, there's also another type of resistance that depends on the width of the tyre". Am I?

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    Brr doesn't account for air resistance or weight which both have an effect on tyre feel.
    – Noise
    Commented May 30, 2021 at 18:30
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    According to Jan Heine the sorts of tests BRR do aren't really reflective of how a tire performs in the real world. More generally tire width isn't as important as how the tire is made (if it is "supple"). FWIW he does claim that a well designed, supple, knobbly tire can roll almost as fast as a well made supple slick tire. renehersecycles.com/bq-tire-test-results
    – GageMartin
    Commented May 30, 2021 at 18:45
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    One thing I’ve always wondered when comparing different widths: How do you choose the pressure for a fair comparison? I think the only fair comparison would be with equal “suspension travel” or equal comfort (i.e. shock/acceleration).
    – Michael
    Commented May 30, 2021 at 19:56
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    @Michael: Sometimes the comparison is at equal pressure with a misguided idea to remove one variable. I would argue (similarly to you) it should be "normal" pressure for the tire, whatever that is. It can be hard to define.
    – Ross Millikan
    Commented May 30, 2021 at 21:46
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    In my opinion the facts that Jan Heine still does not explain his secret methods and does not include commonly available tires in his tests do not help with his credibility
    – ojs
    Commented May 31, 2021 at 7:35

1 Answer 1

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Rolling resistance is a function of tyre width and pressure. If two identical tyres in different sizes are inflated to the same pressure, the wider tyre will have less rolling resistance due to a shorter contact patch. This is explained by Schwalbe here

However usually when we use a wider tyre, we do not use the same pressure we would in a narrow tyre. Bicycle Rolling Resistance did a good test that compared different sizes of the same tyre at the same 'comfort level', which showed tyre width made very little practical difference to rolling speed when set up how you would in the real world. bicyclerollingresistance.com

There is also a large component of materials science and construction know how goes into making a modern high performance tyre, and this is often the real differentiator between brands and models.

In terms of the construction of the tyre; casing material, thread count, number of layers, and extra materials (such as puncture belts) all play a role in the rolling resistance of tyres. Vittoria are well known for their fast casings with a supple feel, and this knowhow means they often feature at the top of rolling resistance charts. In general, higher thread count casings deform to the surface better, and have less rubber between the threads and therefore less material to cause rolling resistance. Vittoria casing information

The final element to consider is the rubber compound. This seems to be something of a dark art with very few people knowing the secrets of the latest rubber compounds. It seems that one person was instrumental in the top compounds used by three major manufacturers. Wolfpack Tires

With all these factors involved in the rolling resistance of tyres, it is not surprising that we can find that a high quality knobby tyre can be faster than some slick tyres.

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  • I think the question is why cyclocross and gravel tires are so consistently bad. If the casing, tread compound and secret sauce from the manufacturer were determining factors, they should be near road racing tires and certainly better than city and touring tires. In practice almost all gravel tires turn out to be slower than Schwalbe Marathon that has heavy puncture protection.
    – ojs
    Commented Oct 25, 2021 at 10:30
  • @ojs I very much agree - I think most gravel tyres are overbuilt. A Conti Terra Speed measures to have more puncture resistance (and hence also rolling resistance) than a Conti Race King. My assumption is that this is because some US gravel races are renowned for having sharp rocks and the nature of the events requires more reliability than for an XC race. However i'd personally much rather see some faster gravel tyres available
    – Andy P
    Commented Oct 25, 2021 at 10:36
  • I do not believe gravel tyres are overbuilt. Schwalbe G-One are quite thin and it is certainly possible to have them punctured by a piece of rock. Not that I trust the data from a roller the said website uses. Most of the data is now behind a paywall anyway.But I might think about buying a Terraspeed for a replacement, the tread pattern is quite similar to a G-One Allround.
    – Vladimir F Героям слава
    Commented Oct 25, 2021 at 10:49
  • @VladimirF They may be quite thin, and it may be possible to puncture them. However similar to the case with Conti, the G-One is slower (and more puncture resistant) than Schwalbes fast MTB tyres with no logical reason for this to be the case. A modern xc tyre is expected to deal with rock gardens. As for trusting the data - it's a shame we don't have more sources verifying the data, but from my own experience with riding many tyres I feel like my feelings match well with the data so i'm happy to trust it.
    – Andy P
    Commented Oct 25, 2021 at 10:53
  • I have a pair of Mavic Yksion Allroads that I think are relabeled version of Hutchinson Overide and I can confirm that they are nice, supple, easily punctured and somehow noticeably slower than SportContacts or similar. The strange thing is that Mavic-branded road tires aren't that bad and other manufacturers' gravel tires don't seem to be better.
    – ojs
    Commented Oct 25, 2021 at 11:08

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