What tyres do the pros tend to use?

nferrar

I'm firmly in the slick tyres are best camp but it's strange that Schwalbe themselves put a diamond file pattern on their aqua tyres (although this could purely be marketing to as the main thing about them is the wetstar compound). Not tried them though as happy enough on my Ultremos

frenchfighter

dougzz wrote:

frenchfighter wrote:

The aviation industry has studied this problem very carefully, and has come up with a general guideline as to when hydroplaning is a risk. The formula used in the aviation industry is:
Speed (in knots) = 9 X the square root of the tire pressure (in psi.)
Tire pressure of 100 psi is 104 mph for Hydroplane speed.
Shiny was correct.

OK, and a 'general guideline' for a 747 weighing 200,000Kgs converts accurately to a bike, mmmm - love your science. I bet that guideline doesn't even convert anywhere near accurately for a car.

Aside from the obvious obtuseness of your points on here which have been adequately refuted, I think I should point out that the weight of a 747 is a lot more than 200k kgs. For both points: http://justfuckinggoogleit.com/

shinyhelmut

frenchfighter wrote:

Aside from the obvious obtuseness of your points on here which have been adequately refuted, I think I should point out that the weight of a 747 is a lot more than 200k kgs. For both points: http://justfuckinggoogleit.com/

Being pedantic a 747 weighs a little less than 200 tonnes (c185), it's the passengers, freight and fuel that add up to the max take off weight of c400 tonnes.

frenchfighter

Yes agreed, but I didn't think it necessary to add that the speed at which aquaplaning occurs matters for safety purposes at full weight.

inkyfingers

Does anybody happen to know the air speed velocity of an un-laden swallow?

shinyhelmut

African or asian?

esspeebee

dougzz wrote:

OK, and a 'general guideline' for a 747 weighing 200,000Kgs converts accurately to a bike, mmmm - love your science. I bet that guideline doesn't even convert anywhere near accurately for a car.

In order to aquaplane, the entire mass of the vehicle in question needs to be lifted by the water under the tyres. Agreed? So, the upwards force that the water needs to exert is directly proportional to the mass of the vehicle.

The speed at which a vehicle will aquaplane is that speed at which the tyre moving forward traps more water underneath it per second than can be pushed to the sides by the downwards force of the vehicle's weight through the tyre. The amount of water trapped under the tyre is a function of the forward speed and the tyre's contact area with the road. The speed with which water can be displaced sideways is a function of the viscosity of water, which for all practical purposes is constant.

So, heavier vehicles need more upwards force from the water under the tyre in order to aquaplane. That upwards force is some multiple of the tyre's contact area times forward speed.

The tyre's contact area is, by definition, the tyre pressure times the vehicle's weight. So, we have something like:

Upward force = some constant * speed * contact area

In order to aquaplane, upwards force must equal weight:

Weight = some constant * aquaplaning speed * contact area
Weight = some constant * aquaplaning speed * weight * tyre pressure

Weight appears on both sides of that equation, and cancels out. The only remaining variables are the aquaplaning speed and tyre pressure, yielding the formula originally quoted once you work out what all the constants are supposed to be. Still love his science?

Jez mon

Sorry being an idiot

tremayne

This from a manufacturer;

On a normal, smooth road, the tread has only limited influence on the ride properties. The grip generated by the tire on the road is almost exclusively the result of the rubber compound.

Unlike a car, a bicycle will not aquaplane as the contact area is so much smaller and the contact pressure is much higher. The floating effect of aquaplaning could only theoretically be achieved on a bicycle ridden at speeds over 200 km/h.

Off road, the tread is very important. In this situation the tread establishes an interlocking cog-like connection with the ground and enables the transmission of all driving, braking and steering forces.

On rough roads, the tread can also contribute to better control.

Will.C

Getting even more off topic now, but exactly is considered rough roads? I'd consider most roads I ride on in Surrey 'rough'.

dougzz

You know what, I did use google, and I found out lots of interesting stuff. Like the weight of a 747, and terms like no precise formula, but 'General Guidelines' based on experimental testing for aircraft. I found out that there are different types of aquaplaning, and that the circumstances for sustaining aquaplaning are quite different to those needed to initiate it. I found out that factors like tread depth, and surface are also important. I also found out that if you think that 'formula' will determine the point at which you aquaplane you may well have a nasty surprise.

confused@BR

The problem with people who carry over the details of car/truck/aeroplane technology to cycling is that they are talking about two different shapes. Truck/etc tyres are essentially, flat; bicycle tyres are round. Tread patterns reduce the area of rubber in contact with the road in most circumstances. They do however, provide a useful, if slightly misleading, wear indicator. Tyre manufacturers exist to sell tyres, they have every incentive to induce you to replace your tyres at the earliest opportunity.

BTW I use Vittoria Randoneurs, which have a tread pattern, I have no problem with a, theoretical, loss of grip as I am slow and ride in a conservative manner i e slow.

ddraver

I aquaplaned over a hyowge mud patch yesterday, Came down a straight bit of stony singletrack at full pelt and did nt have any time to stop, Me and the bike went from spotless to totally covered head to toe in mud in about 5 seconds.

Was great fun!

tonyf34

ddraver wrote:

I aquaplaned over a hyowge mud patch yesterday, Came down a straight bit of stony singletrack at full pelt and did nt have any time to stop, Me and the bike went from spotless to totally covered head to toe in mud in about 5 seconds.

Was great fun!

Nope, you lost traction, you didn't aquaplane over the mud, the hint is in the word, hearstopping and adrenalin pumping at the same time though

ddraver

I think you took that far more seriously than it was intended....

chilipapa

Looking around the team buses and shows. it looks like the pro tubs have tread, diamond mostly. The Contis were file tread. And the pro tub version Schwalbes had tread as well. Yet neither do a competition tyre with such a tread?

joelsim

If Valverde had been using Marathon Plus... :P

sherer

more importantly, which colour is the quickest ?

rick_chasey

Weird thread resurrection.

mechanism

sherer wrote:

more importantly, which colour is the quickest ?

I prefer to ask which colour is the most expensive, because the most expensive will be the quickest.

ContrelaMontre

sherer wrote:

more importantly, which colour is the quickest ?

Black, because they will absorb more light and thus heat up quicker.

drlodge

ContrelaMontre wrote:

sherer wrote:

more importantly, which colour is the quickest ?

Black, because they will absorb more light and thus heat up quicker.

But when they heat up, that increases the air pressure, which makes them too hard and so performance degrades. If my I recall my physics O level, black absorbs light but radiates heat best so they'll actually be cooler...

inseine

drlodge wrote:

ContrelaMontre wrote:

sherer wrote:

more importantly, which colour is the quickest ?

Black, because they will absorb more light and thus heat up quicker.

But when they heat up, that increases the air pressure, which makes them too hard and so performance degrades. If my I recall my physics O level, black absorbs light but radiates heat best so they'll actually be cooler...

I'm pretty sure that Conti say that their black tyres are better than the coloured ones. More carbon content perhaps. I'm not sure it's just aesthetics that make car tyres black.

drlodge

More black = more of the rubbery stuff I suppose. Any dye or coloured stuff isn't rubber so will tend to detract from the qualities of rubber, which will make the tyres less good at gripping, ride quality etc.

richard_farrant

sherer wrote:

more importantly, which colour is the quickest ?

Surely red tyres are quicker?

philbar72

Read that when TTing Tony Martin uses clinchers. he also runs a 58/12 when in full flight.

ridgerider

drlodge wrote:

More black = more of the rubbery stuff I suppose. Any dye or coloured stuff isn't rubber so will tend to detract from the qualities of rubber, which will make the tyres less good at gripping, ride quality etc.

Don't they add 'black' to rubber to give it the colour, rubber is a yucky brown colour normally I think?

monkimark

Carbon black is the black stuff in rubber and it actually improves some qualities of the material - possibly not stickiness though.