Air pressure

: ohhh...really, interesting, can anyone recommend some mtb slicks which
: are weight friendly? and not too expensive.
:
: orfeo
:
:
I have specialized fatboys. 1.25" ~3.1cm. They are slicks with no grooves.
They are pretty good. There are reviews over the web of these tyres. I
think Cycling Australia reviewed them sometime over the last year. Cost
about $40 a tyre.

Peter

Megan Webb wrote:

On this, there check out the thread on hydroplaning. The link below
also explains

http://www.sheldonbrown.com/tyres.html#hydroplaning

You know something...I'm not convinced by this (doesn't mean it ain't
true...I just smell a rat).

For bike tyres it says:

"Bicycles can NOT hydroplane because..."

This is a big statement to make. That is, under all circumstances, no
bike can hydroplane.

"A bicycle tyre has a curved road contact. Since a bicycle leans in
corners, it needs a tyre with a rounded contact area, which tends to
push the water away to either side."

The same would apply to Motorbikes. They too have rounded contact
areas, and lean into corners. But no motorbike rider in their right
mind uses a slick, unless its on a track on a dry day.


"A bicycle tyre is narrower, so not as much water is in contact with the
leading edge at once."

Sounds fair to me, but I'm not sure if this totally rules out aqua-planing.

"The high pressure of bicycle tyres is more efficient at squeezing the
water out from under."

Not quite true. Mountain bike tyre pressures are often the same as that
off a car.

"Cars go much faster than bicycles, again leaving less time for water
to escape. At high bicycle speeds, hydroplaning is just possible for car
tyres, but is absolutely impossible for bicycle tyres."

Note sure about this. Bikes go quite fast, and cars can aquaplane at
fairly low speed.


Does anyone have comments? Has the web site conclusively proved its
point, or is it somewhat lacking?

Mike

Megan Webb wrote:

On this, there check out the thread on hydroplaning. The link below
also explains

http://www.sheldonbrown.com/tyres.html#hydroplaning

You know something...I'm not convinced by this (doesn't mean it ain't
true...I just smell a rat).

For bike tyres it says:

"Bicycles can NOT hydroplane because..."

This is a big statement to make. That is, under all circumstances, no
bike can hydroplane.

"A bicycle tyre has a curved road contact. Since a bicycle leans in
corners, it needs a tyre with a rounded contact area, which tends to
push the water away to either side."

The same would apply to Motorbikes. They too have rounded contact
areas, and lean into corners. But no motorbike rider in their right
mind uses a slick, unless its on a track on a dry day.


"A bicycle tyre is narrower, so not as much water is in contact with the
leading edge at once."

Sounds fair to me, but I'm not sure if this totally rules out aqua-planing.

"The high pressure of bicycle tyres is more efficient at squeezing the
water out from under."

Not quite true. Mountain bike tyre pressures are often the same as that
off a car.

"Cars go much faster than bicycles, again leaving less time for water
to escape. At high bicycle speeds, hydroplaning is just possible for car
tyres, but is absolutely impossible for bicycle tyres."

Note sure about this. Bikes go quite fast, and cars can aquaplane at
fairly low speed.


Does anyone have comments? Has the web site conclusively proved its
point, or is it somewhat lacking?

Mike

Slicks for MTB's are also high pressure - 70 to 110psi, which makes them
still 3 times car tyre pressure. A big difference.
Offroad tyres are lower, but still almost double that of cars, but they
have tread anyway.

I'll start conjecturing now:

Considering a bike tyre's contact patch is the size of a single tread
block on a car, you would need triple the speed on a bike to aquaplane
than a car. (Based on the fact bikes are pushing down on the road 3
times the force than a car per sq.inch)

How much speed do you need to drive a car (with treaded tyres) through a
puddle to aquaplane? 80, 90km? That means 240 or 270kmh on a bicycle..

Hope this helps
GK

Mike Doyle wrote:

Megan Webb wrote:

On this, there check out the thread on hydroplaning. The link below
also explains

http://www.sheldonbrown.com/tyres.html#hydroplaning

You know something...I'm not convinced by this (doesn't mean it ain't
true...I just smell a rat).

For bike tyres it says:

"Bicycles can NOT hydroplane because..."

This is a big statement to make. That is, under all circumstances, no
bike can hydroplane.

"A bicycle tyre has a curved road contact. Since a bicycle leans in
corners, it needs a tyre with a rounded contact area, which tends to
push the water away to either side."

The same would apply to Motorbikes. They too have rounded contact
areas, and lean into corners. But no motorbike rider in their right
mind uses a slick, unless its on a track on a dry day.


"A bicycle tyre is narrower, so not as much water is in contact with the
leading edge at once."

Sounds fair to me, but I'm not sure if this totally rules out aqua-planing.

"The high pressure of bicycle tyres is more efficient at squeezing the
water out from under."

Not quite true. Mountain bike tyre pressures are often the same as that
off a car.

"Cars go much faster than bicycles, again leaving less time for water
to escape. At high bicycle speeds, hydroplaning is just possible for car
tyres, but is absolutely impossible for bicycle tyres."

Note sure about this. Bikes go quite fast, and cars can aquaplane at
fairly low speed.


Does anyone have comments? Has the web site conclusively proved its
point, or is it somewhat lacking?

Mike

Slicks for MTB's are also high pressure - 70 to 110psi, which makes them
still 3 times car tyre pressure. A big difference.
Offroad tyres are lower, but still almost double that of cars, but they
have tread anyway.

I'll start conjecturing now:

Considering a bike tyre's contact patch is the size of a single tread
block on a car, you would need triple the speed on a bike to aquaplane
than a car. (Based on the fact bikes are pushing down on the road 3
times the force than a car per sq.inch)

How much speed do you need to drive a car (with treaded tyres) through a
puddle to aquaplane? 80, 90km? That means 240 or 270kmh on a bicycle..

Hope this helps
GK

Mike Doyle wrote:

Megan Webb wrote:

On this, there check out the thread on hydroplaning. The link below
also explains

http://www.sheldonbrown.com/tyres.html#hydroplaning

You know something...I'm not convinced by this (doesn't mean it ain't
true...I just smell a rat).

For bike tyres it says:

"Bicycles can NOT hydroplane because..."

This is a big statement to make. That is, under all circumstances, no
bike can hydroplane.

"A bicycle tyre has a curved road contact. Since a bicycle leans in
corners, it needs a tyre with a rounded contact area, which tends to
push the water away to either side."

The same would apply to Motorbikes. They too have rounded contact
areas, and lean into corners. But no motorbike rider in their right
mind uses a slick, unless its on a track on a dry day.


"A bicycle tyre is narrower, so not as much water is in contact with the
leading edge at once."

Sounds fair to me, but I'm not sure if this totally rules out aqua-planing.

"The high pressure of bicycle tyres is more efficient at squeezing the
water out from under."

Not quite true. Mountain bike tyre pressures are often the same as that
off a car.

"Cars go much faster than bicycles, again leaving less time for water
to escape. At high bicycle speeds, hydroplaning is just possible for car
tyres, but is absolutely impossible for bicycle tyres."

Note sure about this. Bikes go quite fast, and cars can aquaplane at
fairly low speed.


Does anyone have comments? Has the web site conclusively proved its
point, or is it somewhat lacking?

Mike

Specialized Fat Boys are the slick to get. Thin as you can get them.

I have used them for years. They are fast and don't puncture often.



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--------------------------
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Specialized Fat Boys are the slick to get. Thin as you can get them.

I have used them for years. They are fast and don't puncture often.



--
--------------------------
Posted via cyclingforums.com
http://www.cyclingforums.com