I came off

[Yellow Saddle]

Read what I said again. The issue is the level of hysteresis is different in different tyre designs. This, coupled with the fact that tyres under greater pressure are less prone to deformation per se results in more "bounce" (for want of a better word). The lack of deformation results in upward movement and this reduces downward force and thus friction

You are confusing a bunch of things here.
Hysteresis relates to internal energy losses inside the tyre and other than the heat that it generates that influences the tyre compound, has no validity in the discussion here.
Tyres under greater pressure are less prone to tyre deformation IN THE CASING. The internal pressure does not affect the tread's deformation. That remains constant.
Downforce does affect overall friction but not the coefficient of friction. But I'm not sure why downforce is even under discussion here. If there was any significant "bounce" as you put it, one would not be able to corner. Bicycles corner very well without the aid of suspension, so bounce is moot.

 

[Ajax Bay]

Back on topic, first of all hope your bike's OK, @Rooster1 that you're no more than a bit grazed and that you're back blasting the roads.
A day's gone since your post and many have wished you well. Thanks for posting the video: most of us have been somewhere there.

Its the road conditions that caused it not the tyres

IMO the reason you lost the rear wheel on the white line was that you were braking (see second 03 (no brakes) and following two seconds of the video, quite firmly applied (both)) and you didn't release the levers as you crossed the white lines. You needed to slow down for the corner but you must not have brakes on or be significantly turning across white lines or metalwork, or if you must, expect that you may slide (and recover, because you're expecting it).
Off topic, on a normal asphalt/tarmacced road, tread or lack of it makes no difference to grip ( @bozmandb9 referenced article seems pretty good to me - post #44). Unreasonably high pressures in tyres [ @Rooster1 : I maxxed out the tyre pressure] will increase the likelihood of a bit of bouncing on rough road surfaces, more so at speed, of course, and that can make grip hazardous when necessary braking is added to the mix (ie to the the need to turn to follow the road). You need a combination of decent bike handling skills and a speed suitable for the road, its gradient, the sightlines, conditions and your skill/risk threshold. We can leave @mrj to tread on his road detritus on wide tyres with low pressures in. Others may just ride normal tyres and take note of the leaves, thread their way through, sitting well back up the hills to maximise weight on the rear wheel and thus the amount of power they can put down, before they slip.

 

[Yellow Saddle]

I understood that it was the road that gripped the tyre. I.e weighted tyre deforms and the coarse surface digs into tyre and creates friction.

So I'm in the no tread camp.

Yes, but probably not the way you put it. The courseness at visual level is irrelevant. Tyres perform very well on smooth glass. It is the courseness at molecular level that, when the tyre squeezes into it, the contact area between the two is much larger than the contact path's surface area. Imagine squeezing into a brocolli floret and comparing the surface area of that "contact" area with that of the surface area of a sphere the same size as the piece of broccoli.

Friction is not mechanical in the interlocking sense of the word but electical in the positive attracts negative sense. Imagine an atom as an amoeba with only two components - a negatively-charged mush and a positively-charged mush. The two mushes are in free suspension and can move around. When the amoeba gets close enough to something similar, the negative mush moves to the cell's one end and the positive mush to the other end. Now the amoeba is polar. It will attract and stick to the other amoeba.

The distance is crucial and in the nano scale. If the two amoeba are not very, very close to each other, they won't morph their polarity and attract. This is the Van der Waal's force and technically one of nature's weak forces.

But, Van der Waal is strong enough to provide the centripetal force that keeps your bike from sliding when cornering. It is strong because a very weak force was multipled by very, very close contact.

 

[nickyboy]

You are confusing a bunch of things here.
Hysteresis relates to internal energy losses inside the tyre and other than the heat that it generates that influences the tyre compound, has no validity in the discussion here.
Tyres under greater pressure are less prone to tyre deformation IN THE CASING. The internal pressure does not affect the tread's deformation. That remains constant.
Downforce does affect overall friction but not the coefficient of friction. But I'm not sure why downforce is even under discussion here. If there was any significant "bounce" as you put it, one would not be able to corner. Bicycles corner very well without the aid of suspension, so bounce is moot.

At the risk of this becoming tiresome (see what I did there) for everyone, minimisation of the vertical component when you're cycling is critical to the amount of friction exerted between the tyre and the road. Increase in vertical up force reduces the down force and thus friction is reduced. Coefficient of friction is constant, force reduces so friction between two surfaces reduces. Bikes bounce, chatter, what ever you want to call it. This is caused in part by lack of deformation in tyres which in turn reduces the friction between tyre and road. Less deformation = more vertical movement = less down force = less friction

 

[Ajax Bay]

Increase in vertical up force reduces the down force

What is this vertical up force, please? Surely the 'vertical up force' is the normal reaction (from both tyre contact points) to the weight of the bike and its rider (factored by any 'g' force effect of going into a dip) - the 'down force'. When one tyre bounces/chatters the other's taking the load (so therefore more grip if required).

 

[nickyboy]

What is this vertical up force, please? Surely the 'vertical up force' is the normal reaction (from both tyre contact points) to the weight of the bike and its rider (factored by any 'g' force effect of going into a dip) - the 'down force'. When one tyre bounces/chatters the other's taking the load (so therefore more grip if required).

I don't think that, for example, reduced grip on the front compensated for by increased on the back is such a great thing, Anyway, enough of thread derailments

 

[Ajax Bay]

I don't think that, for example, reduced grip on the front compensated for by increased on the back is such a great thing

Sorry - my abilities of comprehension have failed here ^^^^ (maybe some missing words). And what is the 'vertical up force that reduces the down force' of which you spoke.

 

[cyberknight]

In m y opinion, that's a fact, not an opinion.

I concur , changed tyres after a few of these sort of crashes even taking as slow as i could and i havent fell off since in the same conditions .

 

[MichaelW2]

Wet paint, always aim for the gaps.My local Tesco has an entrace defined by a line of bricks jutting 1" up above the level of the tarmac. On the wide sweeping downhill entrance I almast came off from the bump.

 

[HLaB]

They are definately end of life, and as I said, even climbing a hill they were slipping. I maxxed out the tyre pressure but not sure what it is exactly.

If you maxxed out the tyre pressure you probably have them too hard.

 

[Alan O]

I've found this discussion of tyres very interesting - you folks clearly know a lot more about the theory and practice than I do.

But if I can offer one observation based on my own experience - the biggest factor that's affected my grip (when cornering, when on slippy surfaces, whatever) has not been my tyre tread, it's not been my tyre compounds, not the width, not the inflation pressure... it's been the nut on the saddle

 

[Ajax Bay]

the biggest factor that's affected my grip . . . [has] been the nut on the saddle

I'm having trouble with the nut on my old Brooks saddle, but only when standing out of the saddle. Since I'm invariably seated when cornering and braking - not a factor - for me.

 

[Deleted member 35268]

Old Tyre (RED) vs New

 

[si_c]

Old Tyre (RED) vs New

Nice that Rubino doesn't look too worn though, be interesting to see how you feel about the new tyres, I propose a test ride

 

[ianrauk]

Nice that Rubino doesn't look too worn though, be interesting to see how you feel about the new tyres, I propose a test ride

Agreed. I would say there's plenty of life left in that tyre.