Get a Grip Cornering

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Ajax Bay

Guru
Location
East Devon
Jan Heine (BQ Ed but also Compass Tyres) has written this article: why-slick-tires-dont-stick-well.
Key assumption is that interlocking (ie mechanical) element of grip rubber/road when cornering becomes important, along with the normal adhesion (rubber/road) at the molecular level. Therefore key deduction is that a tyre with small ridges (ie a fine tread) on its shoulders will grip better when leant over. However, unlike the superb work he's done on wider tyres/lower pressures and rolling resistance (taking into account the benefits of better (tyre) suspension on the body), there seems no science behind this; more 'feel'. Rather difficult to test friction thresholds in real life road surfaces. Extract(s) from article:

Shoulders

The tread on the shoulders provides traction when cornering, so it’s of great importance.
The best solution is to provide little ridges that “catch” on the road surface irregularities and thus interlock with the road surface. One advantage compared to the slick race car tires is that the ridges cut through the water when the road is wet, thus providing the interlock even in the rain. On wet roads, the coefficient of friction between road and tire is reduced by more than 50%, so the interlock between tire tread and road surface becomes much more important.
Since the pavement aggregate is random, you want to provide as many interlocking surfaces, oriented in as many directions, as possible. By making the tread as fine as possible, you have a good chance that a rib lines up with the edge of a piece of aggregate in the pavement. That is why small ribs work best.
A criss-crossing pattern of fine ribs maximises interlocking surfaces - standard on high-performance bicycle tires for so many years. In the old days, rubber compounds were much less evolved and provided less friction especially in wet conditions. Without the interlocking ribs, the tires would have been very dangerous in the wet. Modern rubber compounds have improved the coefficient of friction, but interlocking still is important for grip, especially in the wet.
 
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Rooster1

I was right about that saddle
All very well but my elbow still hurts lol
 
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Ajax Bay

Ajax Bay

Guru
Location
East Devon
Can't give that a like but I hope the pain fades. Reiterate YS's thanks to you for posting your 'I came off' thread.
Your video was really thought-provoking and I'm glad you posted it. . . . . It elicited some good debate and you never placed blame anywhere other than on your skill and/or luck at the moment.
 

Old jon

Guru
Location
Leeds
I do not often bite, but I have looked at the article. And I happily ride my bike in the wet. The writer tested two pairs ( presumably, he calls them sets ) of his company's standard tyres and one pair of shaved ( ? tread removed? ) tyres that his company may or may not market. He provides no detail at all beyond that, apart from he fell off on the tyres he had taken a razor to and he cornered badly on another set. Hmmm. He then presents assumption as fact with no meaningful data to bolster his beliefs. As he almost comments, "Slick tires are based his simplified, incomplete understanding of tire grip." As an advert for Compass tyres, I think he may have missed the target.
 

mjr

Comfy armchair to one person & a plank to the next
I hate my stupid new tyres, they have a tread which is making things sloowwwwwwwww. Mistake purchase at £46. Oh well
I suspect the weight and inflexibility resulting from the full-width puncture resistance layer has more to do with it than tread. The compound is Endurance which is used in various tyres, but I think might be slower than their RaceGuard, SBC or Dual "active" and "performance" compounds.

I feel that Marathons are better (due to only the centre being full-thickness PR) and Marathon Almotion are reportedly even better (due to the new OneStar compound). I think all have similar tread.
 

Drago

Legendary Member
I'm a big fat bloater, a grip challenge for any bike tyre, and I've been using modern virtually treadless road tyres for years with nary a mishap. very much a non story.
 

nickyboy

Norven Mankey
It's an interesting hypothesis but until there are some controlled experiments that's all it is, a hypothesis

It should be possible to set up some dynamic rig and test how great an angle a bike can be leant over without loss of traction for differing tyres

Something I didn't understand in the article; motorcycles are rear wheel drive so the front wheel doesn't suffer the same wear as the rear. So why not some shoulder tread on the front at least if this hypothesis is real?
 

Smokin Joe

Legendary Member
The author claims that the grooved tread on a cycle tyre disperses water the same as the tread on a car tyre. Unless someone has altered the molecular structure of water the tiny grooves on a race tyre will shift bugger all.
 
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Ajax Bay

Ajax Bay

Guru
Location
East Devon
someone should tell Jan Heine that bicycle tyres don't, and never have, aquaplaned?
Where in the article did you sense that he doesn't know that? Did you read it? I quote:
"Cyclists don’t have enough power to spin their wheels, and bike tires are too narrow to hydroplane. There is no need to evacuate water from the road/tire interface, and deep groves like those of a car tire serve no purpose."
The author claims that the grooved tread on a cycle tyre disperses water the same as the tread on a car tyre.
I can't find where he says or implies that. Best I can find is: (while cornering "the ridges cut through the water when the road is wet, thus providing the interlock even in the rain." But this is the mechanical interlock argument, not the 'clearing water away' (vehicle) requirement.
 

Smokin Joe

Legendary Member
Where in the article did you sense that he doesn't know that? Did you read it? I quote:


I can't find where he says or implies that. Best I can find is: (while cornering "the ridges cut through the water when the road is wet, thus providing the interlock even in the rain." But this is the mechanical interlock argument, not the 'clearing water away' (vehicle) requirement.
Which is bollocks. The ridges on the edge of a cycle tyre are not deep enough to cut through anything.
 
Location
Loch side.
Where in the article did you sense that he doesn't know that? Did you read it? I quote:
"Cyclists don’t have enough power to spin their wheels, and bike tires are too narrow to hydroplane. There is no need to evacuate water from the road/tire interface, and deep groves like those of a car tire serve no purpose."

I can't find where he says or implies that. Best I can find is: (while cornering "the ridges cut through the water when the road is wet, thus providing the interlock even in the rain." But this is the mechanical interlock argument, not the 'clearing water away' (vehicle) requirement.
I must say, I also interpret that as a variation of the "clearing away the water" theme.

I'm kinda shocked that Jan wrote such nonsense - the mechanical interlocking thing in particular is absolute drivel.
 
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