Siping question

[supton]

Wild thought of the morning, came up while driving in.

Siping gives better ice traction. Is ice traction better when the tire is new, or does it better if the tread block gets shorter and stiffer?

I'm thinking it's better when newer. As torque is applied, the block can distort a bit, and that will tend to push a narrow edge into the ice. But I could very well be wrong...

 

[KGMtech]

Not a tire expert, but I would say this question depends on if you were to do siping on a Summer tire or a Winter tire. Winter tires are a softer compound. I would expect that too much siping will affect the integrity of the rubber - it might chunk off if the siping is too deep or cuts the tread pieces too small to stay fully attached.

Experts can chime in now.

 

[UG_Passat]

Ice is only slippery when there is a thin layer of water on it. The sipes enable the tire to break through the water to get the rubber to grip the ice.

Think ice hockey rink and a game. Beginning of period, it is very slippery. By end, the puck moves slower, players move slower, because the thin layer of water and conditioner is gone

 

[supton]

Originally Posted by UG_Passat
Ice is only slippery when there is a thin layer of water on it. The sipes enable the tire to break through the water to get the rubber to grip the ice.

Think ice hockey rink and a game. Beginning of period, it is very slippery. By end, the puck moves slower, players move slower, because the thin layer of water and conditioner is gone

I thought ice skates worked by concentrating the force into a small area, and the high force caused the ice to melt. Thus making it slippery for the ice skate to work. Which would argue against siping, makes for high contact force.

I get the point about getting water out of the way though.

 

[Rand]

its better when new, more flexible tread blocks, newer rubber.

 

[UG_Passat]

Originally Posted by supton
Originally Posted by UG_Passat
Ice is only slippery when there is a thin layer of water on it. The sipes enable the tire to break through the water to get the rubber to grip the ice.

Think ice hockey rink and a game. Beginning of period, it is very slippery. By end, the puck moves slower, players move slower, because the thin layer of water and conditioner is gone

I thought ice skates worked by concentrating the force into a small area, and the high force caused the ice to melt. Thus making it slippery for the ice skate to work. Which would argue against siping, makes for high contact force.

I get the point about getting water out of the way though.


Ice skates glide on over a thin layer of water. The Zamboni machine puts a mixture of water and conditioner on the ice surface, as its final step. That is why at the beginning of the period players glide faster and the puck is faster. By the end of the period, the ice "dries" out, as the layer of water that was originally on top, is no longer there, so the ice and skates are now riding on a dry ice surface.

But when you need to turn or propel yourself, that's what have sharp edges of the blade is for. The sharp edges break through the thin layer of water to grip the ice. Worn edges don't break through the layer of water as easily.

The melting of the snow from friction is more relevant to tires, since rubber has a higher coefficient of friction than say steel alloy used on ice skate blades. That higher coefficient of friction enables the ice to transforms it into the thin layer of water.

 

[redbone3]

I don't know of any tire manufacturer that sells a siped tire. That might be a hint about the value of siping.

 

[supton]

Originally Posted by redbone3
I don't know of any tire manufacturer that sells a siped tire. That might be a hint about the value of siping.

If not "siping" then what is the name for all the little channels in the rubber tread?
https://www.discounttiredirect.com/learn/tire-sipes

 

[supton]

Originally Posted by UG_Passat
Ice skates glide on over a thin layer of water. The Zamboni machine puts a mixture of water and conditioner on the ice surface, as its final step. That is why at the beginning of the period players glide faster and the puck is faster. By the end of the period, the ice "dries" out, as the layer of water that was originally on top, is no longer there, so the ice and skates are now riding on a dry ice surface.

But when you need to turn or propel yourself, that's what have sharp edges of the blade is for. The sharp edges break through the thin layer of water to grip the ice. Worn edges don't break through the layer of water as easily.

The melting of the snow from friction is more relevant to tires, since rubber has a higher coefficient of friction than say steel alloy used on ice skate blades. That higher coefficient of friction enables the ice to transforms it into the thin layer of water.


Ah. I know nadda about hockey nor ice skating, thank you for the explanation.

So that argues for newer being better--if you can get any torque, then the tread block can deform and push the edge into the ice.

 

[knerml]

Originally Posted by supton
Originally Posted by redbone3
I don't know of any tire manufacturer that sells a siped tire. That might be a hint about the value of siping.

If not "siping" then what is the name for all the little channels in the rubber tread?
https://www.discounttiredirect.com/learn/tire-sipes

Tire sipes are the multiple narrow grooves in the tread blocks.

All tires with effective snow traction have sipes.

GM did a study in the early 1970's, that found that snow traction is mostly provided by the number of "edges" the tire presents to the road surface. This led to the development of all season and modern snow tires, with siping. This is also why large aggressive off road tires are typically not effective snow tires.

 

[MNgopher]

Not sure I buy into the whole explanation of the ice rink as being a good analogy.

The rink is fast after resurfacing because the actual surface of the ice is free of contaminants (often called snow) that is created by the constant wear on the surface of the ice by the blades on the skates, in addition to the ruts created by said skates. Witness in most NHL arenas the shoveling done periodically during the game to remove the "snow" from the surface of the rink to make the surface faster for the puck.

An ice resurfacer (Zamboni) shaves the top layer of ice off and collects in a hopper. Some water is used to collect more debris from the ruts, and squeegeed/vacuumed into the hopper as well (on some units). More water is added behind the squeegee and the "towel" is dragged across the ice to create a smooth surface. The "conditioner" is actually the entire device that shaves the ice, washes the ice, and lays down the new water on the ice (ie: the big heavy thing on the back of the Zamboni). Not an additive to the water/ice. The water may be "conditioned" to maintain a certain chemistry (typically to deal with alkaline salts), but the "conditioner" isn't something that wears out.

The goal is to get the ice resurfaced and frozen as quickly as possible - thus why NHL rinks use two Zambonis - to give additional time for the water to fully freeze. Any liquid water on the surface will actually slow, if not stop, a puck from travelling smoothly.

How that all relates to sipes is another story..

 

[supton]

Originally Posted by knerml
Originally Posted by supton
Originally Posted by redbone3
I don't know of any tire manufacturer that sells a siped tire. That might be a hint about the value of siping.

If not "siping" then what is the name for all the little channels in the rubber tread?
https://www.discounttiredirect.com/learn/tire-sipes

Tire sipes are the multiple narrow grooves in the tread blocks.

All tires with effective snow traction have sipes.

GM did a study in the early 1970's, that found that snow traction is mostly provided by the number of "edges" the tire presents to the road surface. This led to the development of all season and modern snow tires, with siping. This is also why large aggressive off road tires are typically not effective snow tires.


Right, which would contradict redbone3's statement. Seemingly all manufacturers use siping.

 

[redbone3]

I stand corrected. I never thought that the narrow channels in the thread were siping. Siping to me is cutting the thread with a heated blade by some guy at a tire store. Do the tire manufacturers claim their tires are siped? I don't recall any tire ad that mentioned siping.

 

[69GTX]

When I was buying my last set of performance summer tires in 2015, many manufacturers mentioned siping in their tire literature. From what I recall, siping plays a role in channeling away rain water from you tire to road interface.

 

[Virtus_Probi]

Originally Posted by redbone3
I stand corrected. I never thought that the narrow channels in the thread were siping. Siping to me is cutting the thread with a heated blade by some guy at a tire store. Do the tire manufacturers claim their tires are siped? I don't recall any tire ad that mentioned siping.

I copied this from TireRack.com...
"Blizzak DM-V2 tires use Bridgestone's adaptive NanoPro Tech Multicell compound that features a water-loving hydrophilic coating and microscopic bite particles. The Multicell compound remains flexible in below-freezing conditions, wicks water off packed snow and ice while the bite particles deliver more grip and improve braking on glare ice. This compound is molded into a directional tread design featuring 15% more aggressive block edges (than the Blizzak DM-V1 it replaces) where wide lateral and circumferential grooves help channel water, slush and snow away from the contact area for added traction while 3D zigzag sipes increase the number of snow biting edges."
This was actually the first snow tire I looked at.

 

[edyvw]

Originally Posted by Virtus_Probi
Originally Posted by redbone3
I stand corrected. I never thought that the narrow channels in the thread were siping. Siping to me is cutting the thread with a heated blade by some guy at a tire store. Do the tire manufacturers claim their tires are siped? I don't recall any tire ad that mentioned siping.

I copied this from TireRack.com...
"Blizzak DM-V2 tires use Bridgestone's adaptive NanoPro Tech Multicell compound that features a water-loving hydrophilic coating and microscopic bite particles. The Multicell compound remains flexible in below-freezing conditions, wicks water off packed snow and ice while the bite particles deliver more grip and improve braking on glare ice. This compound is molded into a directional tread design featuring 15% more aggressive block edges (than the Blizzak DM-V1 it replaces) where wide lateral and circumferential grooves help channel water, slush and snow away from the contact area for added traction while 3D zigzag sipes increase the number of snow biting edges."
This was actually the first snow tire I looked at.

Sipes also get filled with snow. Snow in sipes provide much better traction and braking when in contact with snow!

 

[HighbrowHillbill]

Originally Posted by Rand
its better when new, more flexible tread blocks, newer rubber.

This within reason. The more tread depth you have the better they will perform. I have hand siped a bunch of different tires. The closer the tire gets to used up the less siping the tire will help.

 

[y_p_w]

Originally Posted by UG_Passat
Originally Posted by supton
Originally Posted by UG_Passat
Ice is only slippery when there is a thin layer of water on it. The sipes enable the tire to break through the water to get the rubber to grip the ice.

Think ice hockey rink and a game. Beginning of period, it is very slippery. By end, the puck moves slower, players move slower, because the thin layer of water and conditioner is gone

I thought ice skates worked by concentrating the force into a small area, and the high force caused the ice to melt. Thus making it slippery for the ice skate to work. Which would argue against siping, makes for high contact force.

I get the point about getting water out of the way though.


Ice skates glide on over a thin layer of water. The Zamboni machine puts a mixture of water and conditioner on the ice surface, as its final step. That is why at the beginning of the period players glide faster and the puck is faster. By the end of the period, the ice "dries" out, as the layer of water that was originally on top, is no longer there, so the ice and skates are now riding on a dry ice surface.

But when you need to turn or propel yourself, that's what have sharp edges of the blade is for. The sharp edges break through the thin layer of water to grip the ice. Worn edges don't break through the layer of water as easily.

The melting of the snow from friction is more relevant to tires, since rubber has a higher coefficient of friction than say steel alloy used on ice skate blades. That higher coefficient of friction enables the ice to transforms it into the thin layer of water.


The theory that skates must glide over a layer of water has supposedly been disproved. It's possible to skate at temperatures so low that ice doesn't melt at all from skates gliding over them.

 

[y_p_w]

Originally Posted by edyvw
Originally Posted by Virtus_Probi
Originally Posted by redbone3
I stand corrected. I never thought that the narrow channels in the thread were siping. Siping to me is cutting the thread with a heated blade by some guy at a tire store. Do the tire manufacturers claim their tires are siped? I don't recall any tire ad that mentioned siping.

I copied this from TireRack.com...
"Blizzak DM-V2 tires use Bridgestone's adaptive NanoPro Tech Multicell compound that features a water-loving hydrophilic coating and microscopic bite particles. The Multicell compound remains flexible in below-freezing conditions, wicks water off packed snow and ice while the bite particles deliver more grip and improve braking on glare ice. This compound is molded into a directional tread design featuring 15% more aggressive block edges (than the Blizzak DM-V1 it replaces) where wide lateral and circumferential grooves help channel water, slush and snow away from the contact area for added traction while 3D zigzag sipes increase the number of snow biting edges."
This was actually the first snow tire I looked at.

Sipes also get filled with snow. Snow in sipes provide much better traction and braking when in contact with snow!

Not necessarily the sipes since there's not much area, but definitely the grooves. There are a lot of winter and all-season tire tread designs that are meant to have snow trapped in the grooves since snow sticks to snow. This one has a choppy set of grooves meant to keep snow from falling out.

However it's kind of odd. At least in California there's a requirement for "snow tread tires" about the depth of the tread blocks. In order to meet the requirement, an M+S tire needs to have at least 6/32" tread depth to qualify where those alone can substitute for chains. But with true winter tires the tread is going to be filled with snow that stays there, so exactly what's the purpose of requiring tread depth? A good winter tire isn't really using its tread depth to do much since the tread doesn't really bite through the snow.

 

[y_p_w]

The other thing that might be important when it comes to wear for a tire with such a soft compound is how cold it is. It's going to be softer and mushier in higher temps, and will wear faster. But if it's consistently in cold temps it will probably last longer.

I've actually seen winter tires in the San Francisco Bay Area before. Looked like a car that was taken on ski trips during winter, but where the owner didn't feel like changing the tires all the time. They were "performance winters" though, which I suppose might compromise a bit on winter traction in exchange for better dry performance and better wear in dry conditions.