I came off

[gavroche]

I also think the white paint on the road got you. No matter the tyre tread , the result would have been the same.

 

[johnnyb47]

I think both sides of the camp have equal and valid reasons as to whether a slick or treaded tyre are the best. If you just go out on a ride for 10 miles , how many different road surfaces do you encounter. Nice and smooth , recently stone chipped to patched work quilt road surface's. All these various road surfaces we encounter will suit a treaded better and then a slick. There's no definitive answer as to what's the best tyre because are roads are not constant enough to cater for a particular type of tyre. If there's lying snow or you cycle though muddy conditions it a definite yes for treaded but on a clean public road it's anybody's guess at any given point of the highway as to what's the most suitable tyre.
I'll just grab my tin hat now and hide behind to wall lol :-)

 

[Yellow Saddle]

I think both sides of the camp have equal and valid reasons as to whether a slick or treaded tyre are the best. If you just go out on a ride for 10 miles , how many different road surfaces do you encounter. Nice and smooth , recently stone chipped to patched work quilt road surface's. All these various road surfaces we encounter will suit a treaded better and then a slick. There's no definitive answer as to what's the best tyre because are roads are not constant enough to cater for a particular type of tyre. If there's lying snow or you cycle though muddy conditions it a definite yes for treaded but on a clean public road it's anybody's guess at any given point of the highway as to what's the most suitable tyre.
I'll just grab my tin hat now and hide behind to wall lol :-)

No need to hide, help is on its way. No lolling either, this is serious stuff.

Here's a rule of thumb for you wrt bicycle, motorcycle and aeroplane tyres.

If the road is harder than the tyre, then the tyre requires no tread.
If the road is softer than the tyre, then the tyre requires tread.

The various "types" of hard road you encounter has no effect on whether you need tread or not.

 

[cyberknight]

I did, I know. I committed Too fast, too wet.

He says that to everyone !

GWS.

 

[Yellow Saddle]

In my opinion, the biggest influence on grip on a road tyre is not the tread, but the compound.

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

 

[mjr]

If the road is harder than the tyre, then the tyre requires no thread.
If the road is softer than the tyre, then the tyre requires thread.

They all require thread, to hold the rubber into shape

Seriously, I'm riding over leaf mulch on roads these days. Last month, it was harvest mud. In a few months, it'll be some other shoot. I'll keep on having a little tread, thanks.

 

[Yellow Saddle]

They all require thread, to hold the rubber into shape

Seriously, I'm riding over leaf mulch on roads these days. Last month, it was harvest mud. In a few months, it'll be some other shoot. I'll keep on having a little tread, thanks.

I've fixed the tread in this thread. Thanks for pointing out.

 

[Deleted member 35268]

main thing is you are ok little bruised and bashed but still fit to cycle, after an accident like that not a single driver stopped to see you where all right perhaps no one noticed?

The Saab pulling out did pause to check i was OK, I waved him an OK. By the time other cars were passing, I was upright and faffing about and not in obvious pain (aside from the general groaning noises I made).

 

[nickyboy]

Not a smart-arse response, but a tongue in cheek comment as this Schwalbe statement is regularly brought up as evidence when this topic is discussed, and I was certainly expecting it when I made my reply

Appeal to authority, is when a statement from a source of perceived authority is used as evidence that the statement is correct.

In this case, the assumption that Schwalbe's statement about tyres is correct, as they are in the industry of selling tyres.

Their primary purpose though is to market, and sell the tyres.

As I say though, their statement does not stack up against physics too well, nor any academic source. Regardless of surface area (or contact patch), the coefficient of friction between the materials will remain the same.

http://www.physlink.com/education/askexperts/ae140.cfm

As that link elegantly puts it, if you increase the surface area, you also decrease the pressure, this exactly offsets the increase in surface area, thus results in no increase in friction. You would need to increase surface area, AND the pressure.

The assumptions in the standard model tend to fail when the object is small enough to dig into the other surface, this isn't at the tiny level of road tyres, but when you have knobbly tyres on a loose surface.

100% agree on the theoretical physics aspect that surface area contact doesn't influence frictional forces. However, you have to consider what is really going on when your tyre comes into contact with the road. Of course it deforms to "mould" to the shape of the road surface, that's the friction in principle. However what it also does is bounce over road surface imperfections and the down force is reduced and thus friction is reduced. So what influences the amount of "bounce"? How readily your tyre deforms and how hard the road surface imperfections are. Some tyre compounds will deform more readily than others so these will exert greater frictional forces

It is also true to say that if you pump up your tyres more and more, the surface area in contact with the road reduces. But also the tyre becomes less able to deform so friction is reduced this way. Less surface area in contact in this case results in less friction

 

[Deleted member 35268]

Ouchiees.

I found Rubinos towards the end of their life because there so hard wearing (can't remember a p'ture) were a bit skitty. Money was a bit tight when I had them so I lowered the pressure to mitigate the skittishness rather than buying a new tyre and never had a problem after that. What pressure are you running?

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.

 

[Deleted member 35268]

One of the most shocking videos I've seen in a long while. How can anyone go out in daylight with cables that don't match?


Oh, sorry about the fall, hope you heal up quick.


Now go swap those cables 100 times

Sorry about the cables, must sort.

 

[Yellow Saddle]

100% agree on the theoretical physics aspect that surface area contact doesn't influence frictional forces. However, you have to consider what is really going on when your tyre comes into contact with the road. Of course it deforms to "mould" to the shape of the road surface, that's the friction in principle. However what it also does is bounce over road surface imperfections and the down force is reduced and thus friction is reduced. So what influences the amount of "bounce"? How readily your tyre deforms and how hard the road surface imperfections are. Some tyre compounds will deform more readily than others so these will exert greater frictional forces

No, Surface area contact does influence friction. This contact is influenced both by tyre compound and by downforce. But "contact" is not as simple as as an area.

It is also true to say that if you pump up your tyres more and more, the surface area in contact with the road reduces. But also the tyre becomes less able to deform so friction is reduced this way. Less surface area in contact in this case results in less friction

No. The contact patch may shrink but pressure (downforce per area) between road and tyre increases and friction is equalised. The equation is almost perfectly balanced - as pressure increases (contact patch grows smaller) the friction increases.

 

[Deleted member 35268]

I am annoyed I did not go for the Graphene Vittorias now as a replacement

Vittoria Rubino Pro G+ Isotech Folding Tyre

 

[lutonloony]

glad your OK apart from hurt pride. I find that I normally take a hoof down the tarmac when I have got new clothing on, thus ensuring it quickly matches the state of my old stuff with rips, tears and blood stains!!

 

[nickyboy]

No, Surface area contact does influence friction. This contact is influenced both by tyre compound and by downforce. But "contact" is not as simple as as an area.



No. The contact patch may shrink but pressure (downforce per area) between road and tyre increases and friction is equalised. The equation is almost perfectly balanced - as pressure increases (contact patch grows smaller) the friction increases.

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