Why slick tires don’t stick well?
Moonbiker
Posts: 1,706
So true or false?
https://janheine.wordpress.com/2016/01/05/why-slick-tires-dont-stick-well/#comments
Im sure im read lots or forum opinions that say slicks are just as grippy as bike tyres can't "aqua plain"so any grip pattern does nothing.
https://janheine.wordpress.com/2016/01/05/why-slick-tires-dont-stick-well/#comments
Im sure im read lots or forum opinions that say slicks are just as grippy as bike tyres can't "aqua plain"so any grip pattern does nothing.
0
Comments
-
Pseudo-engineering of the worst kind and with a confused argument and lack of understandingROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0
-
Its fairly standard marketing technobabble, on the whole. Just enough that makes sense to disguise the bits that don't.Pseudo-engineering of the worst kind and with a confused argument and lack of understanding
There's something in the idea of tyres having to conform to the road surface in order to grip. Thing is, slicks do that anyway.
Love the attempt to distinguish between negative treads and raised treads though. 10/10 for effort.
Now, if he really wanted to befuddle the reader, he should have claimed that tread movement causes the tyre to heat up and provides more grip. Or he could bang on about the "chemical interaction with the road" like David Coulthard does. Which really is bollicks.0 -
slicks are not "just as grippy" as treaded tyres.
OK, so you're not going to "aquaplane" but that is not the point.
It's the bit before you get full film separation that the grip reduces (rather than disappearing all together); essentially the load is shared between the water and the tyre.
From a tribological perspective its the difference between elastohydrodynamic and hydrodynamic.
That's my opinion any way, others are available.0 -
Had to google what tribological means:
& I Just found theese links on the CTC forum
http://forum.ctc.org.uk/viewtopic.php?f=5&t=102720&sid=f567efef2480213948fd97113c6886e7
http://automotive.ing.unibs.it/~gadola/Michelin/GRIP.PDF
see page labelled p69 (not p69 in the pdf)
http://www.nhtsa.gov/staticfiles/safercar/pdf/PneumaticTire_HS-810-561.pdf
see p429 onwards0 -
slicks are not "just as grippy" as treaded tyres.
OK, so you're not going to "aquaplane" but that is not the point.
It's the bit before you get full film separation that the grip reduces (rather than disappearing all together); essentially the load is shared between the water and the tyre.
From a tribological perspective its the difference between elastohydrodynamic and hydrodynamic.
That's my opinion any way, others are available.
So why did the bloke from Continental say in an interview with Cyclist mag a couple of months ago that slicks were just as grippy, tread pattern made absolutely no difference and that it was just there for psychological/marketing/aesthetic reasons?
Just wonderin' like, as he happens to make tires.Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
slicks are not "just as grippy" as treaded tyres.
OK, so you're not going to "aquaplane" but that is not the point.
It's the bit before you get full film separation that the grip reduces (rather than disappearing all together); essentially the load is shared between the water and the tyre.
From a tribological perspective its the difference between elastohydrodynamic and hydrodynamic.
That's my opinion any way, others are available.
So why did the bloke from Continental say in an interview with Cyclist mag a couple of months ago that slicks were just as grippy, tread pattern made absolutely no difference and that it was just there for psychological/marketing/aesthetic reasons?
Just wonderin' like, as he happens to make tires.
market differentiation0 -
To me its about feel not absolute grip, unless your panic cornering!
so the michelin pro 4 grip with a cut tread pattern on the shoulders feels better in the wet than their slick pro 4 sc or comp, but does feel slower compared to pro4 sc.
the other tires i run, veloflex corsa and carbon, have fishbone tread and feel fantastic in the wet and v fast in the dry.
is it down to compound or tread, i doubt anyone on here really knows, all in the eye of the beholder 0 -
slicks are not "just as grippy" as treaded tyres.
OK, so you're not going to "aquaplane" but that is not the point.
It's the bit before you get full film separation that the grip reduces (rather than disappearing all together); essentially the load is shared between the water and the tyre.
From a tribological perspective its the difference between elastohydrodynamic and hydrodynamic.
That's my opinion any way, others are available.
What I think you are talking about is, again, essentially whether or not there is a film of water between your tyre and the road. I think your point is, as with others, if your tyre has pointy bits, it increases local pressure and cuts through said film, like ickle elephants wearing stilettos.
You either believe it helps, or you believe that the contact point of a bike tyre is so small already that it doesn't. But with longer words which help to deflect critical analysis.
I guess to really know, you'd have to consider whether tiny raised file marks (or other small surface features) on a bike tyre are actually sufficiently resilient to be capable of providing a significant increase in the pressure applied to the road surface. If, for example, they are compressed flat with the rest of the tyre at a fraction of the forces required to make a jot of difference, I'd argue that they would then be merely decorative.
I looked at those links. I'm not even going to begin to pick away at the terminology used in the Michelin pdf. Okay, I am. By "molecular contact" they mean "contact". But in a more sciencey way. Kind of like moisturizing cream being like trapping water against your skin by applying an oil base emulsion. But in a more expensive way. So, the take home message is "buy our tyres" and not a whole lot more.0 -
Its also worth noting that Conti do have nice decorative "treads" on a lot of their tyres, so at least he's being honest.slicks are not "just as grippy" as treaded tyres.
OK, so you're not going to "aquaplane" but that is not the point.
It's the bit before you get full film separation that the grip reduces (rather than disappearing all together); essentially the load is shared between the water and the tyre.
From a tribological perspective its the difference between elastohydrodynamic and hydrodynamic.
That's my opinion any way, others are available.
So why did the bloke from Continental say in an interview with Cyclist mag a couple of months ago that slicks were just as grippy, tread pattern made absolutely no difference and that it was just there for psychological/marketing/aesthetic reasons?
Just wonderin' like, as he happens to make tires.0 -
I guess to really know, you'd have to consider whether tiny raised file marks (or other small surface features) on a bike tyre are actually sufficiently resilient to be capable of providing a significant increase in the pressure applied to the road surface. If, for example, they are compressed flat with the rest of the tyre at a fraction of the forces required to make a jot of difference, I'd argue that they would then be merely decorative.
I agree with this (and quite like the condescending tone ) I'd add that unless you are riding on a perfectly flat surface the gaps in the tarmac or small stones or any other number of things would make much more difference than any squidgy bits of rubber would. www.conjunctivitis.com - a site for sore eyes0 -
How hard would this be to test? Not very is the answer. But, at the sort of contact pressures we're talking about, intuitively I find it hard to believe that some little rubber file serrations are going to make a jot of difference especially on a surface where the irregularities are an order of magnitude larger.ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0
-
The point I was trying to make was that you don't have to aquaplane to have a reduction in grip. Most of the arguments made by the tyre companies are around aquaplaning, where the whole tyre is no longer in contact with the surface and is highly unlikely. In reality, a REDUCTION in grip is often enough to send you off down the road on your back and is much more likely.
My own tyres? lithion 2's and I don't remember if they have tread.0 -
well that blogger is certainly talking out of his posterior about how racing slick/treaded tyres work, as a for instance there are several of national level motorbike racing series who use treaded tyres and not slicks,race at racing speeds and their tyres dont rip apart, and Michelin have made fully slick tyres that work in near full wet racing conditions, so frankly I rate the rest of it as pseudo scientific nonsense too
the actual rubber tyre compound,tyre construction and air temperatures (ie winter or summer) its suited to are going to make the most difference to grip on a bicycle tyre, if your tyre is suited for winter its probably of limited grip in the summer and vice versa.0 -
well that blogger is certainly talking out of his posterior about how racing slick/treaded tyres work, as a for instance there are several of national level motorbike racing series who use treaded tyres and not slicks,race at racing speeds and their tyres dont rip apart, and Michelin have made fully slick tyres that work in near full wet racing conditions, so frankly I rate the rest of it as pseudo scientific nonsense too
the actual rubber tyre compound,tyre construction and air temperatures (ie winter or summer) its suited to are going to make the most difference to grip on a bicycle tyre, if your tyre is suited for winter its probably of limited grip in the summer and vice versa.
Dude
As powerful as my bandy legs of power are, I doubt that they are putting out enough wattage to trouble the compound of any bicycle tyre known to man - I haven't chewed a set of tires up in all my racin' years.
Motorbike treaded race tires are essentially cut slicks - utterly different to what you use on the road (which is why they generally have "not for road use" all over. I know this because I used to use them on the road).
Motorbike race tires will "tear apart" no matter what compounds if you do one or all of several things: run too hot, run too cold, incorrect tyre pressures, incorrect suspension settings amongst many.
You'll find that they generally run treaded tires in the race series' where you have to by the rules (super stock, etc). BSB, Superbike on the Irish roads, that sort of thing will only ever run treaded in the damp/wet as they just aren't as good as slicks. Which is why you don't see Valentino and John McPint heading to Carnell's for a set of Pirelli Corsa Rosso/Avon Phukatons on Friday night ready for race weekend
Bicycle tires will not have different compounds for summer or winter and the rubber will work exactly the same. Underneath the rubber is where the difference will be - the Chilli compounds and that malarkey.
A "winter tyre" will work 100% perfect in the summer and vice versa.
Personally I use whatever is blackest and cheapest on the winter bike (has been Vittoria Zaffiro slicks at £6 each for the past 10 years and have had, maybe, 6 punctures in thousands of commuting and training miles).Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
Generally when people say "aquaplaning" they mean dynamic aquaplaning where a tyre rises onto the surface of the water. This is highly unlikely on a bicycle due to pressure, and tread in this case is irrelevant. However if you are referring to viscous aquaplaning which relies on the film strength of water trapped between two smooth surfaces (lubrication) then tread does make a difference. Two very smooth surfaces will produce viscous aquaplaning at very low speeds and very high pressures. Generally the road surface is not all that smooth, but in cases where there are lines painted or metal road furniture or even very old coarse aggregate that has been polished over time even slightly treaded tyres are less smooth than the road surface, so will improve grip. As an example of how much tread is needed, your finger prints are sufficient to allow you to pick up a wet glass. Without fingerprints you become a clutz and randomly drop things at the slightest hint of moisture.
So why did the guy from Continental, the biggest tire manufacturer in the whole world, say the opposite - ie tread does not make an iota of difference?
Just wonderin' like.Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
Taking this argument to it's logical conclusion, the knobblies on my CX bike should grip much better on wet tarmac than the slicks on my road bike. That's not my experience. Being dis-inclined to test this theory in a corner, I base my opinion on wheel spin/slip when climbing the same 14% hill on the two bikes; CX knobblies slip most.0
-
Generally when people say "aquaplaning" they mean dynamic aquaplaning where a tyre rises onto the surface of the water. This is highly unlikely on a bicycle due to pressure, and tread in this case is irrelevant. However if you are referring to viscous aquaplaning which relies on the film strength of water trapped between two smooth surfaces (lubrication) then tread does make a difference. Two very smooth surfaces will produce viscous aquaplaning at very low speeds and very high pressures. Generally the road surface is not all that smooth, but in cases where there are lines painted or metal road furniture or even very old coarse aggregate that has been polished over time even slightly treaded tyres are less smooth than the road surface, so will improve grip. As an example of how much tread is needed, your finger prints are sufficient to allow you to pick up a wet glass. Without fingerprints you become a clutz and randomly drop things at the slightest hint of moisture.
Almost no road surface is that smooth by dint of the materials used. Sure, if the roads were glass smooth, there would be a problems - but the mechanisms you describe would equally apply to cars and, in particular, motorbikes. The truth is, though, that road surfaces are rough at the scale we are talking about and cannot support thin film lubrication. Water doesn't make a very good lubricant either.
If this effect was as marked as suggested, we'd all know that textured tyres made a difference. The truth is that we don't. In fact, from what I can think, there's almost no correlation between the tyres people recommend for wet grip and those tyres being "treaded".
And, whilst everyone agrees none of us have awesome power to break traction in the wet, we all brake. We all also know that braking distances in cars are extended in the wet. So any argument, as presented in the blog, that you only need "tread" for cornering would be (if the mechanism was correct - which it isn't) false.
As I said, none of this stands up to scrutiny.ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
Because he sells tyres and probably doesn't have a degree in thin film fluid dynamics. How many car salesman know anything about cars?Generally when people say "aquaplaning" they mean dynamic aquaplaning where a tyre rises onto the surface of the water. This is highly unlikely on a bicycle due to pressure, and tread in this case is irrelevant. However if you are referring to viscous aquaplaning which relies on the film strength of water trapped between two smooth surfaces (lubrication) then tread does make a difference. Two very smooth surfaces will produce viscous aquaplaning at very low speeds and very high pressures. Generally the road surface is not all that smooth, but in cases where there are lines painted or metal road furniture or even very old coarse aggregate that has been polished over time even slightly treaded tyres are less smooth than the road surface, so will improve grip. As an example of how much tread is needed, your finger prints are sufficient to allow you to pick up a wet glass. Without fingerprints you become a clutz and randomly drop things at the slightest hint of moisture.
So why did the guy from Continental, the biggest tire manufacturer in the whole world, say the opposite - ie tread does not make an iota of difference?
Just wonderin' like.
Ahhhh - so Continental, the biggest tire firm in the world, making bicycle, car, motorbike, aero plane and every other tire type known to man are just a inch of snake oil salesmen budging something together just to shift a few units?
Blimey mate - you should give them a call and see if there's a job for you. Corner the tire development market you could......
Or perhaps that as the firm is worth literally worth billions, I'd take a punt that they have this covered already.
I'm with the guy from the tyre company.
But hey, it's worth a shout and it'll only cost a phone call.Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
Dolan Titanium ADX 2016
Ridley Noah FAST 2013
Bottecchia/Campagnolo 1990
Carrera Parva Hybrid 2016
Hoy Sa Calobra 002 2014 [off duty]
Storck Absolutist 2011 [off duty]
http://www.slidingseat.net/cycling/cycling.html0 -
Generally when people say "aquaplaning" they mean dynamic aquaplaning where a tyre rises onto the surface of the water. This is highly unlikely on a bicycle due to pressure, and tread in this case is irrelevant. However if you are referring to viscous aquaplaning which relies on the film strength of water trapped between two smooth surfaces (lubrication) then tread does make a difference. Two very smooth surfaces will produce viscous aquaplaning at very low speeds and very high pressures. Generally the road surface is not all that smooth, but in cases where there are lines painted or metal road furniture or even very old coarse aggregate that has been polished over time even slightly treaded tyres are less smooth than the road surface, so will improve grip. As an example of how much tread is needed, your finger prints are sufficient to allow you to pick up a wet glass. Without fingerprints you become a clutz and randomly drop things at the slightest hint of moisture.
You know, I think you are right with this.
Run your finger down a dry window pain and your finger sticks to it. Run said finger down a window pain with condensation and the water lubricates the surfaces. Any cyclist must be aware that friction between the road and the tyre is reduced in wet because the wheels lock easier when breaking in the wet.
But it is mainly a problem in the situations you mention - white lines, metal gratings - I slipped off on railway lines in the rain once. On normal road the rough surface provides all the tread necessary.0 -
Ahhhh - so Continental, the biggest tire firm in the world, making bicycle, car, motorbike, aero plane and every other tire type known to man are just a inch of snake oil salesmen budging something together just to shift a few units?
Well they do make tyres they describe a having 330tpi casings when they are actually 3 layers of 110tpi casings. Using their nomenclature Vittoria must be making tyres with 990tpi casings.0 -
Generally when people say "aquaplaning" they mean dynamic aquaplaning where a tyre rises onto the surface of the water. This is highly unlikely on a bicycle due to pressure, and tread in this case is irrelevant. However if you are referring to viscous aquaplaning which relies on the film strength of water trapped between two smooth surfaces (lubrication) then tread does make a difference. Two very smooth surfaces will produce viscous aquaplaning at very low speeds and very high pressures. Generally the road surface is not all that smooth, but in cases where there are lines painted or metal road furniture or even very old coarse aggregate that has been polished over time even slightly treaded tyres are less smooth than the road surface, so will improve grip. As an example of how much tread is needed, your finger prints are sufficient to allow you to pick up a wet glass. Without fingerprints you become a clutz and randomly drop things at the slightest hint of moisture.
You know, I think you are right with this.
Run your finger down a dry window pain and your finger sticks to it. Run said finger down a window pain with condensation and the water lubricates the surfaces. Any cyclist must be aware that friction between the road and the tyre is reduced in wet because the wheels lock easier when breaking in the wet.
But it is mainly a problem in the situations you mention - white lines, metal gratings - I slipped off on railway lines in the rain once. On normal road the rough surface provides all the tread necessary.
no one is arguing that things are slippery when wet.
the debate is whether tread on tyres helps in the wet. I generally go by the rule, tread is only useful on a bike if you leave a 'foot' print on the surface you are cycling on. Like in mud for example.www.conjunctivitis.com - a site for sore eyes0 -
if we're honest, most of us are more interested in getting the logos lined up with the valves than whether any tread helps with grip.0
-
if we're honest, most of us are more interested in getting the logos lined up with the valves than whether any tread helps with grip.
Ne'er a truer word said my man!
Well, that and what makes the best noise when pulling skids.Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
if we're honest, most of us are more interested in getting the logos lined up with the valves than whether any tread helps with grip.
Ne'er a truer word said my man!
Well, that and what makes the best noise when pulling skids.
just before christmas one of my workmates retired. As his leaving present he chose a folding bike for his boat so when he moors up in Holland he can deploy it and pootle off to buy waffles, beer and skunk. On his last day he brought it in to the office to show us. Since we have a large, open plan office I had a go on it. He said he didn't realise it went that fast. I said I wasn't expecting much from the brakes, but they locked up completely and now I have a 6 foot skid mark across the NEW pale grey carpet and pointing straight at my desk :shock:0 -
The biggest tyre manufacturer may surprise a few
http://www.lego.com/en-gb/aboutus/news-room/2012/june/guiness-world-record-to-the-lego-groupwww.conjunctivitis.com - a site for sore eyes0 -
I think, certainly hope, that we've established that the energies and forces, the heat and dynamics in motorsport are on a different planet and not relevant to a discussion of bicycle tyres.
Wrong type of tread. Tread designed for dirt does a totally different job to tread designed for wet but firm surfaces. Look at the difference between a GP wet tyre and a motoX tyre.Taking this argument to it's logical conclusion, the knobblies on my CX bike should grip much better on wet tarmac than the slicks on my road bike. That's not my experience. Being dis-inclined to test this theory in a corner, I base my opinion on wheel spin/slip when climbing the same 14% hill on the two bikes; CX knobblies slip most.
We are looking at a black rubber tube with a smooth-ish surface and full contact area versus a black rubber tube with multiple, small contact patches which do not sum up to the former's total contact area. A treaded road tyre would fall somewhere between these two extremes. And the correlation I find is that, on wet tarmac, the large contact area wins over the small.
I would also add in passing that several bicycle tyre manufacturers have reported that a lightly used (scrubbed-in to use motorsport terminology) slick tyre has better wet grip than a brand new one. (I can dig out a link if required.) Still a slick tyre, still a large contact patch but enough surface texture to allow water to be cleared away.0 -
I'm less sure that tyres in motorsport have no place in this discussion. There are definitely limits to the applicability but perhaps closer than you think. The tyres on my race car are semi-slick (occasional finger-width water channels), they're 7" wide but with only about 200kg (more at the front, less at the rear) through each contact patch. The local contact pressure is probably less than my bike tyre but broadly in the same order. When the track is wet (we only use the one tyre) the surface of the tyre is cold (so no temperature considerations) and race tracks tend to be much smoother surfaces than regular highways - especially in the corners. What I do get is a very good idea of the change in grip on a wet track though a chunk of this is due to the tyres being cold (when compared with fully warmed tyres).
What is clear is that the "lubrication" effect of water is of a completely different order from "aquaplaning". A wet track is more slippery but entirely predictable and does have a good degree of grip (even on cold, effectively slick, tyres) whereas aquaplaning is, effectively, instantaneous zero grip.
Another direct comparison is that proper "wet" racing tyres are of a soft compound and that gives some clues as to what makes a tyre grip in the wet. As I say, in proper wet weather, these tyres are constantly cooled by the water on the track. The internal pressure (good measure of the heat) hardly changes. Wet weather tyres in cycling (Vittoria Open Paves for instance) are also a softer compound - cut easier and wear out quicker.
Another lesson from car racing is that predictability is as important, in some ways, as grip. Having confidence to lean your bicycle in the same way is really important (as anyone who has had a spill will know).ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
if we're honest, most of us are more interested in getting the logos lined up with the valves than whether any tread helps with grip.
Ne'er a truer word said my man!
Well, that and what makes the best noise when pulling skids.
just before christmas one of my workmates retired. As his leaving present he chose a folding bike for his boat so when he moors up in Holland he can deploy it and pootle off to buy waffles, beer and skunk. On his last day he brought it in to the office to show us. Since we have a large, open plan office I had a go on it. He said he didn't realise it went that fast. I said I wasn't expecting much from the brakes, but they locked up completely and now I have a 6 foot skid mark across the NEW pale grey carpet and pointing straight at my desk :shock:
Nice - very nice.
Reminds me of the time a friend got incredibly drunk at a mutual friend's house. The mutual friend, for some reason still unknown to this day, had a tattoo gun, although he wasn't, isn't and never will be a tattooist.
Needles to say, when friend N1 woke up with a 10 inch penis tattooed down his leg he may have been startled.Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
if we're honest, most of us are more interested in getting the logos lined up with the valves than whether any tread helps with grip.
Ne'er a truer word said my man!
Well, that and what makes the best noise when pulling skids.
just before christmas one of my workmates retired. As his leaving present he chose a folding bike for his boat so when he moors up in Holland he can deploy it and pootle off to buy waffles, beer and skunk. On his last day he brought it in to the office to show us. Since we have a large, open plan office I had a go on it. He said he didn't realise it went that fast. I said I wasn't expecting much from the brakes, but they locked up completely and now I have a 6 foot skid mark across the NEW pale grey carpet and pointing straight at my desk :shock:
Nice - very nice.
Reminds me of the time a friend got incredibly drunk at a mutual friend's house. The mutual friend, for some reason still unknown to this day, had a tattoo gun, although he wasn't, isn't and never will be a tattooist.
Needles to say, when friend N1 woke up with a 10 inch penis tattooed down his leg he may have been startled.
Flying back from a family holiday in Corfu, there was a bunch of lads who'd clearly been living it up in the mosquito infested south of the island; they were all covered in bites. One of their number made the mistake of falling asleep. When he woke up he filed down the aisle, and patiently waited his turn to use the toilet. Then we suddenly heard an explosion of obscenities and he came back down the plane hurling a torrent of abuse at his former chums; he'd obviously glanced in the mirror and seen the c0ck and balls in permanent marker on his forehead. 0
