Are my tires splitting?

[strat61caster]

Originally Posted by DM7

Decades ago many tires did not have grounding strips. Cars would build up static charge as they drove along and shock the occupants when they stood on the ground exiting and entering. Some people installed anti static straps to prevent static charge from building up while driving.

I owned a set of Motomaster AW (my fellow Canadians know this budget tire brand) tires five years ago that did not have grounding strips built into them. I would get a zap each time I closed the door as I was leaving the car after a long drive.

Ok I'll bite, how does the charge get from the wheel to the 'grounding strip' portion of the tire?

[churchx]

Magic.

[DM7]

Originally Posted by strat61caster

Ok I'll bite, how does the charge get from the wheel to the 'grounding strip' portion of the tire?

Rubber compounds can be formulated to be just a little bit conductive creating a path from the wheel to the tire.

[soundman98]

Originally Posted by DM7

Decades ago many tires did not have grounding strips. Cars would build up static charge as they drove along and shock the occupants when they stood on the ground exiting and entering. Some people installed anti static straps to prevent static charge from building up while driving.



I owned a set of Motomaster AW (my fellow Canadians know this budget tire brand) tires five years ago that did not have grounding strips built into them. I would get a zap each time I closed the door as I was leaving the car after a long drive.

Do you have a source? Because i can't find any information on this anywhere besides forums and reddit threads. Many petroleum facilities where I'm at still require the grounding straps like that picture for any vehicles entering.

[soundman98]

Originally Posted by strat61caster

Ok I'll bite, how does the charge get from the wheel to the 'grounding strip' portion of the tire?

It can't, simply put. think of the how's and where's any static charge has a chance to be built up, and how many poorly conductive connections and materials are between the solid chassis where most charges get built up and the wheel hub--the only solid metal piece firmly connected to the wheel assembly.

[humfrz]

Originally Posted by strat61caster

Ok I'll bite, how does the charge get from the wheel to the 'grounding strip' portion of the tire?

This may help explain it.

"Static electricity can be a problem with tires. Static electricity and an inadequate electrical ground can be a real concern when you’re refueling, or when you’re sliding out of the car. Modern tire compounds feature less carbon black to cut rolling resistance and weight, but that also means a tire that’s less conductive for an electric ground between the vehicle and the road surface. The solution is an “antenna tread” in the tire’s surface – a thin, continuous strip of rubber that serves as an efficient conductor between the tire and pavement so the vehicle is always grounded."


https://patents.google.com/patent/US7029544B2/en


humfrz

[DM7]

Originally Posted by soundman98

Do you have a source? Because i can't find any information on this anywhere besides forums and reddit threads. Many petroleum facilities where I'm at still require the grounding straps like that picture for any vehicles entering.

I used to work in a tire factory. We only made tires for passenger cars and light trucks (F150, Silverado, Ram). All of our tires had a grounding strip in the tread cap. Not all makes and models of tires have grounding strips because as far as I know it's not a DOT requirement. It's not a feature the marketing teams can do much with to spin it into a selling point for consumers so it mostly remains industry knowledge. Considering how obscure this bit of knowledge is; I'm not surprised that petroleum facilities will take all precautions to make sure vehicles are properly grounded and have decided the best way to do that is to require vehicles to have grounding straps.

Best I could find is this quote.

"Static electricity can be a problem with tires. Static electricity and an inadequate electrical ground can be a real concern when you’re refueling, or when you’re sliding out of the car. Modern tire compounds feature less carbon black to cut rolling resistance and weight, but that also means a tire that’s less conductive for an electric ground between the vehicle and the road surface. The solution is an “antenna tread” in the tire’s surface – a thin, continuous strip of rubber that serves as an efficient conductor between the tire and pavement so the vehicle is always grounded.

https://tires3.com/blog/view/4-thing...not-have-known

[strat61caster]

Originally Posted by DM7

Rubber compounds can be formulated to be just a little bit conductive creating a path from the wheel to the tire.

Then why bother with a strip? Especially in the center, the charge will just bleed out through the compound that's less conductive because it can get to ground faster.

[DM7]

Originally Posted by strat61caster

Then why bother with a strip? Especially in the center, the charge will just bleed out through the compound that's less conductive because it can get to ground faster.

It's hard to formulate compounds that "do it all". The grounding strip only needs to be millimetres wide so they use a small amount of specific compound in the centre of the tread. The rubber used for the grounding strip probably doesn't have any other desirable traits like low rolling resistance, high grip, low durability, heat tolerance or cost to be justified being used on the entire tread cap. It's easier to make the rest of the tread of high grip rubber for performance. Or low rolling resistance rubber for fuel economy.

[86MLR]

This is something I had no clue about.

Aerials in my tyres, time for tin foil on my head.

I smell a conspiracy

[ermax]

Originally Posted by strat61caster

Then why bother with a strip? Especially in the center, the charge will just bleed out through the compound that's less conductive because it can get to ground faster.

I think you have the definition of conductive backwards. If something is “less conductive” that means it is “harder” to pass electricity through. The wire is added to make the tires “more” conductive so that energy is dissipated easier. The thing that I find odd is that tires are already full of steel belts. What difference would this additional wire make? Maybe it runs from the bead and then to the ground?

[maslin]

Originally Posted by ermax

I think you have the definition of conductive backwards. If something is “less conductive” that means it is “harder” to pass electricity through. The wire is added to make the tires “more” conductive so that energy is dissipated easier. The thing that I find odd is that tires are already full of steel belts. What difference would this additional wire make? Maybe it runs from the bead and then to the ground?

Not a wire, just a different compound of rubber down the center. Seems to be a lot more discussion in the motorcycle world, “antenna tread” brings up lots results on Google.

Come to think of it, some of the tires I put on at the shop have a small raised ridge down the middle. Not a casting line, a regularly shaped raised portion, maybe 4mm x 2mm or so? Haven’t paid much attention to it, Contis maybe?

“Motorcycle tires have a lot of different materials in the compound. One in particular, silica, helps the rubber heat up quickly and improves grip in cold and wet conditions. One drawback of silica is that it's a good electrical isolator. Tires with rubber compounds that use a lot of silica build up a static-electricity charge as you ride, sometimes enough to give you a light shock when you put your foot on the pavement, becoming the ground in the circuit.

According to our source from one of the major motorcycle tire manufacturers, that line around your tires is called "antenna tread." Unlike the rest of the compound that makes up the tire, this line doesn't have any silica in it, so it dissipates the static electricity as you ride rather than letting it accumulate. Antenna tread isn't new or peculiar to any one brand. All motorcycle tire manufacturers build it into their tires—even car and truck tires have it—though it's much harder to see there because of the dense tread pattern. The visible line of antenna tread might fade or disappear over time, but meanwhile it's nothing to worry about.”

[norcalpb]

Hi guys, just wanted to mention my tires wore down back to normal so thank you again for the help and informative thread.