In praise of titanium - and Spa Cycles

[Yellow Saddle]

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



I will post any reply I get.

My I reply on their behalf?

"Because most people believe that it would not do us any good to put counter-intuitive real science in our marketing literature. The same goes for the concept of bicycle tyres with tread which are not better in the rain that smooth tyres, but if we try and market a smooth tyre for all conditions, someone else will bullshit the market and steal our market share."

 

[PhilDawson8270]

There is confusion.

Wide tyres roll slower. Not due to the additional friction, but due to deformation on the leading edge.

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

You will have to provide a source for one that claims wide tyres provide more grip due to increase contact patch.

 

[Yellow Saddle]

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

And to spread wear over a larger surface and therefore last longer.

 

[Yellow Saddle]

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.

I think @PhilDawson8270 answered that one nicely. I would still like you to complete my pen materials experiment and post the results.
Speaking of inappropriate materials. If you have a fancy for today's large watches with dials and buttons and propellers and things, you'll know that they are really heavy and actually not all that comfortable to wear, especially in active environments for which, ironically, they were designed. They swing around on your arm like a sledgehammer on a necklace. One watch company, Sector, came up with a solution and instead of milling the watch body out of stainless steel or indeed, titanium, they do it from aluminium and then hard anodize it for either a greyish Ti look or a shiny chrome/stainless steel look. Obviously the body is still strong enough for the job and if the anodizing does its job, corrosion won't be an issue. Therefore, I think aluminium is a more appropriate material for a big chunky watch that requires a metal look. The best of the bunch is of course a Casio G-Shock made from plastic. But that doesn't mean a gold Rolex hasn't got a niche market somewhere.

 

[Profpointy]

I think @PhilDawson8270 answered that one nicely. I would still like you to complete my pen materials experiment and post the results.
Speaking of inappropriate materials. If you have a fancy for today's large watches with dials and buttons and propellers and things, you'll know that they are really heavy and actually not all that comfortable to wear, especially in active environments for which, ironically, they were designed. They swing around on your arm like a sledgehammer on a necklace. One watch company, Sector, came up with a solution and instead of milling the watch body out of stainless steel or indeed, titanium, they do it from aluminium and then hard anodize it for either a greyish Ti look or a shiny chrome/stainless steel look. Obviously the body is still strong enough for the job and if the anodizing does its job, corrosion won't be an issue. Therefore, I think aluminium is a more appropriate material for a big chunky watch that requires a metal look. The best of the bunch is of course a Casio G-Shock made from plastic. But that doesn't mean a gold Rolex hasn't got a niche market somewhere.

Yebbut, you've already conceded (I think?) that titanium is strong and light, so why is that a bad thing for bikes, but a good thing for aircraft (the latter point you've said isn't a sensible comparison, but I don't follow the argument why)

OK, titanium is difficult to work with, and may not be readily available in the tubing you'd ideally choose, but neither of these points make the material itself unsuitable.

 

[stoatsngroats]

If you think about the rear tyre on a bike being braked, and then the front brake being applied additionally, the rear wheel becomes more likely to lock.. true..?
If you agree then ask why, it's because the 'load' on the rear tyre has been reduced by the centre-of-gravity moving forwards because the front brake and tyre are causing deceleration, (nothing else has changed) which means the rear tyre has less load, not necessarily any less contact.... this shows that contact area doesn't necessarily dictate grip (or friction), but the load changing does.

 

[Profpointy]

If you think about the rear tyre on a bike being braked, and then the front brake being applied additionally, the rear brake becomes more likely to lock.. true..?
If you agree then ask why, it's because the 'load' on the rear tyre has been reduced by the centre-of-gravity moving forwards because the front brake and tyre are causing deceleration, (nothing else has changed) which means the rear tyre has less load, not necessarily any less contact.... this shows that contact area doesn't necessarily dictate grip (or friction), but the load changing does.

If you unload the back tyre (as you indeed will) then the contact patch reduces as well. If you break hard, the back wheel will lift and you'll have zero load, zero friction, and surprise surprise, zero contact patch.

 

[stoatsngroats]

If you unload the back tyre (as you indeed will) then the contact patch reduces as well. If you break hard, the back wheel will lift and you'll have zero load, zero friction, and surprise surprise, zero contact patch.

Yep, (this is of course if you brake with the front hard enough) but I didn't mention unloading the back wheel, merely reduced the load..... I brake gently (and with the front brake only! )

 

[Profpointy]

Yep, (this is of course if you brake with the front hard enough) but I didn't mention unloading the back wheel, merely reduced the load..... I brake gently (and with the front brake only! )

it'll still reduce the contact patch as the tyre will flex / spread less with less weight on it

 

[Profpointy]

There is confusion.

Wide tyres roll slower. Not due to the additional friction, but due to deformation on the leading edge.



You will have to provide a source for one that claims wide tyres provide more grip due to increase contact patch.

Uh, google - I might add Wikipedia on slip angles

 

[Pale Rider]

Wide tyres, like for like apart from width - roll better than narrow ones.

Schwalbe again: http://www.schwalbe.com/en/rollwiderstand.html

Continental also say the same.

No doubt some posters will say it's yet more rubbish, this time from two tyre makers.

But why would the companies put rubbish in an information sheet?

Both will quite happily sell you a narrow tyre or a wide one.

Another question: Why have the pros largely switched to wider tyres?

It's not because the team bosses want to give their riders an easier ride.

 

[PhilDawson8270]

Wide tyres, like for like apart from width - roll better than narrow ones.

Schwalbe again: http://www.schwalbe.com/en/rollwiderstand.html

Continental also say the same.

No doubt some posters will say it's yet more rubbish, this time from two tyre makers.

But why would the companies put rubbish in an information sheet?

Both will quite happily sell you a narrow tyre or a wide one.

Another question: Why have the pros largely switched to wider tyres?

It's not because the team bosses want to give their riders an easier ride.

Their comments with regards to rolling resistance make sense, and seem to be accurate. A narrower tyre with a smaller surface area will have a greater force than a wider tyre, with the same inflation pressure, the narrower tyre will have more deformation. It is the deformation that determines how well a tyre rolls.

But note, even they say that if you run the narrower tyre at a higher pressure they can roll the same. There are many variables, and I will concede my comment was a little too general.

 

[PhilDawson8270]

Uh, google - I might add Wikipedia on slip angles

I don't fancy randomly googling for potential sources. If you have seen anything that supports your view, please do post it.

 

[Citius]

Another question: Why have the pros largely switched to wider tyres?

It's not because the team bosses want to give their riders an easier ride.

(slightly) Wider tyres roll better for a given pressure - but the improvement is not linear. In other words, the principle would not extend to running 45mm tyres and expecting to see the same benefit. If it did, I imagine the pros would all be riding fatbikes.

I don't know the percentage of the pro peloton that has gone from 23 -> 25, but it is most likely at the enouragement of their tyre sponsors.

 

[Milkfloat]

Oh, by the way Pale Rider, congrats on the new bike, it looks like a corker.