"The simple truth is that side knobs don’t help with cornering traction"

Gravel Myths (5): Side Knobs for Cornering Traction? – Rene Herse Cycles

Rene Herse has come out and said that side knobs don’t help with cornering traction on gravel bikes.

To me, this is shocking.

Does anyone agree with these assertions? If this were remotely the case, then why do mountain bike tires always have side knobs yet gravel bikes are generally ridden in the same places?


Quite frankly, I think that while he may be knowledgeable about some things, he’s generally full of hot air. Someone can correct me if I am misstating this, but I believe he has also claimed that 48mm tires have no aerodynamic detriment compared to 28s. I find it interesting to hear his opinions, but I would never take what he says as fact without corroborating evidence from another party.


I’ve ridden the specialized pathfinders that came on my Diverge sport (they are sawtooth pattern) and I’ve ridden my Nanos with nice side knobs and and the only place my pathfinders are better is on the road. I have way more tractions in all non-paved roads with the nanos. My 2 cents.

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I’m of the opinion that no, knobs dont do anything in gravel; reason being that when you lose traction in gravel…it’s because stones move, not because your tires werent able to grip the stones properly.

That’s not to say knobs arent useful…I think they are very helpful on soft, stable sufaces that dont move - mud.


Knobs don’t grip gravel. Knobs grip soft earth. Hardpack tyres should be about reliable deflection.

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I can’t get their page to load, so maybe they broke the internet.

For gravel and XC, I’m of the opinion that volume and casing suppleness can in many cases reduce the need for knobs, and come with the benefit of reduced rolling resistance.

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It worked for me the 2nd time but didn’t load the first time either. On the laptop I went to the address bar and pressed return. It wouldn’t give the option to refresh for some reason. I thought it was my cr@p laptop.

To elaborate on this further…

Knobs require 2 things. A surface that wont move, AND a surface the knob can penetrate. Only then is there a benefit. That’s why knobs suck on pavement, and dont help on gravel.

For a more extreme example…picture running around in baseball cleats on a tile floor. Or, see if baseball cleats help you at the beach.

  • So slicks for mud, snow and sand are the winning choice?

For sand, slicks very well could be the best choice.

Snow and mud, no. I mean this is all on a spectrum. But assuming there is earth somewhere under the mud, you definitely want knobs. Or if the mud is peanutbuttery mud; that stuff is super clumpy, it’s not going anywhere generally. And packed snow actually offers quite a bit of resistance to being smushed sideways.

Greasy mud on top of pabement? Good luck there…knobs arent going to do much.

Where it gets tricky I think, is when you have a moveable surface on top of something soft and stable. Think…loamy dirt or sand on top of wetter, more solid earth. Then you have to decide if the knobs are big enough to cut through down to the surface with grip…

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No, not in the same way that loose gravel does.

Have you ever seen a ski slope?

Loose gravel I think knobs still aid traction. I know for myself descending a gnarly gravel road/4wd track on DHR tyres and there’s more grip for sure than an equivalent Rekon Race or Aspen, and they’ve both got (small) side knobs.

Jan’s tires at cyclocross courses here in the PNW…


Knobs on dry gravel

I’m sorry but no, slicks are not the best for sand lol

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This was a pair of GK SS+ after 4 miles of mud in the SF Bay. Slick center, minimal side lugs. If anything the lugs retained mud.

That said, for Sea Otter Gravel, I’ll be running Nanos because that’s the kind of roads/dirt that we’ll be hitting out there. Unbound will be GK SS+ or SK+. I ran SK+ last year in the 100 no issues, even in the mud pit. Leaning toward the SS+ for the deuce this year

My point was indirect… that stating near absolutes the way he did is a mistake in a world ruled by nuance, IMO.

“Gravel” has a massive range in what that means and it is more subjective than people give it credit. As such, listing tire recommendations without more specific statement of the road conditions is less than ideal. I’ve ridden “gravel” that was faster than tarmac or covered with river rock the size of a fist… sometimes on the same ride.

Considering the often varied nature of gravel at least in my area, you can take my bike away if you want to take away my knobs. I am happy to have them when I need them, and that’s more often than not for me.


Yeah, really course conditions play a huge role in tire selection (shocking, I know).

My Dead Swede Gravel race last year could have been done on 23mm slicks. There was one section where the gravel got big and chunky, but that was for only 5 miles. The remainder might as well have been tarmac.

The previous year, I was happy to be on my XC bike with knobs. I could take the sweeping downhill corners with decent speed and it could grip the loose gravel very nicely.

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In this conversation the definition of gravel needs to be agreed upon before anything else is discussed.

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For the TL;DR crowd, I think this quote from the article sums up Jan Heine’s argument reasonably well:

“Gerard Vroomen, co-founder of Cervelo and Open, explained this years ago:

“‘In general we find side knobs superfluous on gravel tires. If you’re hanging at such an acute angle, you’re about to hit the ground anyway. Even worse, the only terrain where you could achieve such an angle without falling is on asphalt, and the last thing you want is side knobs hitting the road instead of smoother rubber.’”

Hence the title on the article. My reading is that they think if you’re gonna run a knobby on gravel, then a full knobby (specifically like the ones they sell!) is the right choice. It’s almost like there’s a marketing component here haha.

Disclosure: I have a Bicycle Quarterly subscription and use Rene Herse tires (slicks, thanks for asking) on my main bike. And I plan to buy a set of their knobbies one my Teravail Cannonballs wear out.


I agree. I immediately thought of some sweet singletrack I like to ride my gravel bike on. The side knobs definitely help out on that type of terrain. Some dirt roads are just that - dirt. Knobs would help on those too, I would think.

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