In praise of titanium - and Spa Cycles

[PhilDawson8270]

Would you concede the term 'inappropriate' is not, er, appropriate in this case?

It suggests the material is not capable of doing the job, as in chocolate is an inappropriate material for a fire guard.

Not necessarily. From @Yellow Saddle posts, I guess he either has some personal mechanical engineering knowledge, or comes from a mechanical engineering background.

But an inappropriate material isn't one that is unusable. But one that is obviously not the best choice.

To go back to the biro analogy. You could make it from titanium, it would work. But it's not really, from an engineering view, an appropriate material. It will do the job, it's strong enough, light enough. But there are plastics that are cheaper, easier to manufacture, lighter.

Now, there is no doubt a titanium pen (I have a titanium ring, of course an aluminium ring will do the same job). But, it's a fashion thing. An exotic material for those who want to use it.

It's appropriate to use one on an aircraft, but a bicycle. No, not really

 

[Pale Rider]

Oh so sorry, but I can't let this one go.

More surface area does NOT equal more grip. Friction is independent to area.

Schwalbe would give you an argument:

"On a normal, smooth road, even in wet conditions, a slick tire actually provides better grip than a tire with a tread, because the contact area is larger."

http://www.schwalbe.com/en/profil.html

 

[PhilDawson8270]

Schwalbe would give you an argument:

"On a normal, smooth road, even in wet conditions, a slick tire actually provides better grip than a tire with a tread, because the contact area is larger."

http://www.schwalbe.com/en/profil.html

They're wrong

Frictional Force = coefficient of friction * Reactive Force

Nowhere in any equation for friction is surface area a factor.

 

[Pale Rider]

They're wrong

Frictional Force = coefficient of friction * Reactive Force

Nowhere in any equation for friction is surface area a factor.

They might be wrong, but they are a respected tyre maker.

They also have no vested interest in the sense they couldn't give a stuff if you buy a slick or treaded tyre, provided it's a Schwalbe one.

Seems to me more tyre on road = more grip, all other things being equal.

A couple of posters in this thread need to be wary of applying engineering principles too closely to a bicycle.

It is a strange and wonderful contraption which doesn't always behave in the way a text book might indicate.

 

[PhilDawson8270]

They might be wrong, but they are a respected tyre maker.

They also have no vested interest in the sense they couldn't give a stuff if you buy a slick or treaded tyre, provided it's a Schwalbe one.

Seems to me more tyre on road = more grip, all other things being equal.

A couple of posters in this thread need to be wary of applying engineering principles too closely to a bicycle.

It is a strange and wonderful contraption which doesn't always behave in the way a text book might indicate.

More tyre does not equal more grip, it never has and never will.

Engineering principles, and basic physics such as friction apply to bicycles as well as everything else on this planet. The laws don't change because it is on a bicycle.

A nice explanation here of why friction doesn't increase with surface area:

"Although a larger area of contact between two surfaces would create a larger source of frictional forces, it also reduces the pressure between the two surfaces for a given force holding them together. Since pressure equals force divided by the area of contact, it works out that the increase in friction generating area is exactly offset by the reduction in pressure; the resulting frictional forces, then, are dependent only on the frictional coefficient of the materials and the FORCE holding them together. "

 

[Pale Rider]

More tyre does not equal more grip, it never has and never will.

Engineering principles, and basic physics such as friction apply to bicycles as well as everything else on this planet. The laws don't change because it is on a bicycle.

A nice explanation here of why friction doesn't increase with surface area:

"Although a larger area of contact between two surfaces would create a larger source of frictional forces, it also reduces the pressure between the two surfaces for a given force holding them together. Since pressure equals force divided by the area of contact, it works out that the increase in friction generating area is exactly offset by the reduction in pressure; the resulting frictional forces, then, are dependent only on the frictional coefficient of the materials and the FORCE holding them together. "

So why do sports cars - and at the extreme F1 cars - have very wide tyres?

It is surely so they will, in the right hands, go around bends at ridiculous speeds, rather than going straight on.

Another reason must be to get lots of power down without the wheel spinning.

Grip of a tyre on a road, which is what I'm on about, may not be the same as friction as discussed in a classroom.

 

[jowwy]

That's called a 'straw man' argument, by the way. First we have 'appeal to authority', then 'straw man' - can we go for the full set?

Oh i have missed the third sibbling in the equation who only picks up on my posts.

We have the responder = ys
The defender of the responder = cyclist33
Now the trollette of any post by me = citius

In this case the trollette added nothing to the post other than to just quote my posts for his self worth

 

[Citius]

Oh i have missed the third sibbling in the equation who only picks up on my posts.

We have the responder = ys
The defender of the responder = cyclist33
Now the trollette of any post by me = citius

In this case the trollette added nothing to the post other than to just quote my posts for his self worth

That's another ad hominem. Does that score separately or is it just added to the previous one..??

As for the bit in bold - obviously you've never ever done that yourself in any thread on these forums. Can we add hypocrisy to the list..??

 

[PhilDawson8270]

So why do sports cars - and at the extreme F1 cars - have very wide tyres?

It is surely so they will, in the right hands, go around bends at ridiculous speeds, rather than going straight on.

Another reason must be to get lots of power down without the wheel spinning.

Grip of a tyre on a road, which is what I'm on about, may not be the same as friction as discussed in a classroom.

They use wide tyres to dissipate the heat. If you had a bicycle size tyre on an F1 car they would melt them pretty damn fast. It is purely to have a large area in which to dissipate the heat.

 

[Citius]

What I will say in relation to this thread is that 'confirmation bias' has an extremely powerful influence on people. I have suffered from it myself. I remember being slightly underwhelmed when I went for my first ride on a new Ti frame - it was nothing like I was expecting and not obviously better than the steel frame it replaced. I convinced myself it was better though.

I had a similar experience when riding my first carbon frame. I had read all the press reviews of carbon frames and was expecting it to "surge forward with every pedal stroke" like all the magazine reviews keep saying. It didn't. It built into a light bike though.

 

[Profpointy]

Oh so sorry, but I can't let this one go.

More surface area does NOT equal more grip. Friction is independent to area.

I thought that was only true for O-level physics classical friction. Rubber on road isn't quite as simple as I understand it - eg racing cars have wide tyres

 

[PhilDawson8270]

I thought that was only true for O-level physics classical friction. Rubber on road isn't quite as simple as I understand it - eg racing cars have wide tyres

Exactly the same, it also applies to their clutches and brakes. The size is purely to dissipate heat

 

[PhilDawson8270]

I have also just emailed Schwalbe, asking them to explain how their tyres have more grip for a wider area,

Hi,

During a discussion on a cycling forum called cyclechat.net your site and page http://www.schwalbe.com/en/profil.html was quoted as a source of evidence with regards to sick tyre friction.

Your site states, "a slick tire actually provides better grip than a tire with a tread, because the contact area is larger."
This seems to be contrary to the equation for frictional force

Frictional force = Coefficient of Friction * Reactive Force

Since when the contact area increases, with the same force, the pressure holding the surfaces together reduces, thus contact area having no effect on the friction of the tyre and road.

Can you please explain, what physical mechanism allows for Schwalbe tyres to have more grip due to a larger contact area.

Many Thanks,
Phil Dawson

I will post any reply I get.

 

[Profpointy]

tyre widths - try google. Quite a lot of explanations of the variety of subtle reasons wide tyres give more grip - mostly on Physics type websites, not the car equivalent of this place. Heat dissipation didn't feature that highly

 

[midlife]

Formula 1 clutch is smaller in diameter than the tablet I am holding

Way smaller than the one in my 1.2 Clio

Shaun