Make my own silent tyres

[GSLex]

Hello my friends,

Normally I am driving on 245-45-18 Dunlop with NST (Noise shield technology)
These tyres are extremely silent because they have a layer of foam sticked in the inside of the tyre on the part of the thread.

Since I can't mount these tyres anymore because I have found my ultra rare Japanese dream rims which are way wider then original I am planning to mount. It will be 215-50-18 in the front and 225-50-18 in the rear.

There are no manufacturiers who make "extra silent" foam tyres in this size and since the technique is just a layer of foam I thought I could do this trick myself. I have seen many kinds of cheap and expensive kinds of foam in my life and I am pretty sure that the foam in my Dunlop tyres isn't the state of the art stuff.

I have a thick layer of silent coat sticked into the interior of my car and that stuff feels way better. More little air bubbles per inch.

My idea is to cut the foam really precise in a strip and stick it in the tyres myself. I am aware that thats needs to be cut and sticked in really precise.

My question to you guys is. Could there be any big or small risk to this idea? Big risk in a way of damaging the tyre after a wile causing an accident or a small risk like making some bad vibrations in the steering wheel.

I am really interested in your thoughts!

 

[Jetronic]

the foam needs to be open cell, you want to dampen the pressure waves created by the rolling and deforming tyres. The biggest risk is heating up of the tyre especially if the foam is too closed.

 

[nobb]

I think someone attempted this elsewhere and the biggest issue is getting the foam to reliably adhere to the tire long term. Getting two materials to stick under a wide range of thermal and mechanical forces is actually quite difficult.

 

[GSLex]

the foam needs to be open cell, you want to dampen the pressure waves created by the rolling and deforming tyres. The biggest risk is heating up of the tyre especially if the foam is too closed.

What a super interesting answer. This is extremely helpful! I never thought about it this way and believe me. I have thought about it quite much.

The "Silent Coat" foam doesn't have an open cell on top. The top layer has a very very thin layer of plastic which is made of the same material as the foam. I think they did this so water couldn't enter it.

The thickness of the "Silent Coat" foam is 10mm. Do you think it could heat it up so much that it could blow the tyre?

 

[GSLex]

I think someone attempted this elsewhere and the biggest issue is getting the foam to reliably adhere to the tire long term. Getting two materials to stick under a wide range of thermal and mechanical forces is actually quite difficult.

That sounds like a really important aspect! Since I have experimented with putting this stuf on my car I have experienced that when I stick it somewhere, it doesnt come off. This stuff is sticking really hard and it comes off in pieces. (Thats why cutting it straight is almost impossible. I need a laser cutter or something.) But I havent thought about the wide range of therminal and mechanical forces.....

When I see both the answers which have been given in this topic, I'm starten to think that my idea is quite risky and can couses quite some trouble....

 

[AZjeff]

99.9% chance it won't stick and you'll end up with a loose band of foam inside your tire or worse it balls up and goes out of balance. (Consider wheel weights come in 1/4 ounce increments.) Then you have to dismount the tires from your cool ultra rare dream rims again risking damage.

Credit for wanting to try things. Quiet tires is a big deal?

 

[eljefino]

Don't do this.

Whatever rubber cement you plan to use has to be strong enough to hold the foam but weak enough so its solvents don't dissolve the actual tire.

This is something that needs to be engineered by tire engineers.

 

[nobb]

That sounds like a really important aspect! Since I have experimented with putting this stuf on my car I have experienced that when I stick it somewhere, it doesnt come off. This stuff is sticking really hard and it comes off in pieces. (Thats why cutting it straight is almost impossible. I need a laser cutter or something.) But I havent thought about the wide range of therminal and mechanical forces.....

When I see both the answers which have been given in this topic, I'm starten to think that my idea is quite risky and can couses quite some trouble....

Yea even the most strongest feeling glue that seems permanent...can still have failure points. I remember where I saw this now, there is a 17 page discussion on a Tesla forum of someone having spent a bunch of time and money testing this out and his conclusion was that it was very difficult and not worth it.

I would personally love to attempt this, but I'm not sure how you get around the bonding aspect and it takes a lot of special R&D and equipment I would imagine. Any consumer or industrial glue isn't going to work unless you spend a bunch of time learning and figuring out the chemistry behind such a bond. I was thinking perhaps with an open cell foam, you could bond a sort of rubberized substrate (think of how air filters have that bonded surrounding foam gasket), then use a vulcanizing component like rubber cement to vulcanize the substrate to the tire itself?

One of the challenges is that although we call tires "rubber", there's a lot of special chemistry behind it to make them durable and resistant to chemical attack or degradation. That's why you can have a set of tires exposed to the elements (various oils, acids, salt, etc...) for a decade and still be safe to drive on. Rubber on a tire is pretty darn inert to many strong chemicals.

Another thought I had was what if instead of bonding, you had a compressed foam chunk inside the tire that holds itself mechanically (expansive force). But then again you have to keep this pretty secure because any shift in weight would throw off your balancing. Lastly, instead of trying to bond foam to the rubber tire, I wonder if there would be any value to securing sound dampening material to the rim itself (which is more acoustically reflective) via straps.

 

[Gimpy1]

WHY?

 

[CapriRacer]

GSLex,

You're new here, so allow me to introduce myself. I used to work as an engineer for a major tire manufacturer. Among the things I did was answer questions that came through our 800 number or the internet.

You should be aware that when tires are manufactured, they put a mold release agent on the inside so the curing bladder releases when the tire comes out of the mold. That release agent needs to be removed to get anything to stick to it.

I do not know for a fact that Dunlop cleans the inside when they apply the foam, but I can not imagine anything else. I also do not know what might dissolve it (not a chemist.).

But I do know that certain chemicals will dissolve the innerliner. Among these are gasoline and brake cleaners. The only thing I am sure will not dissolve the innerliner is alcohol. I do not know how effective alcohol would be as a cleaning agent.

It appears to me that the mold release agent will be your biggest obstacle.

 

[SubLGT]

....Since I can't mount these tyres anymore because I have found my ultra rare Japanese dream rims which are way wider then original I am planning to mount. It will be 215-50-18 in the front and 225-50-18 in the rear....

What car are these dream rims for?

 

[Vercingetorix]

Can you adhere the foam to the wheel?

 

[GSLex]

What car are these dream rims for?

Lexus LS430

 

[GSLex]

Yea even the most strongest feeling glue that seems permanent...can still have failure points. I remember where I saw this now, there is a 17 page discussion on a Tesla forum of someone having spent a bunch of time and money testing this out and his conclusion was that it was very difficult and not worth it.

I would personally love to attempt this, but I'm not sure how you get around the bonding aspect and it takes a lot of special R&D and equipment I would imagine. Any consumer or industrial glue isn't going to work unless you spend a bunch of time learning and figuring out the chemistry behind such a bond. I was thinking perhaps with an open cell foam, you could bond a sort of rubberized substrate (think of how air filters have that bonded surrounding foam gasket), then use a vulcanizing component like rubber cement to vulcanize the substrate to the tire itself?

One of the challenges is that although we call tires "rubber", there's a lot of special chemistry behind it to make them durable and resistant to chemical attack or degradation. That's why you can have a set of tires exposed to the elements (various oils, acids, salt, etc...) for a decade and still be safe to drive on. Rubber on a tire is pretty darn inert to many strong chemicals.

Another thought I had was what if instead of bonding, you had a compressed foam chunk inside the tire that holds itself mechanically (expansive force). But then again you have to keep this pretty secure because any shift in weight would throw off your balancing. Lastly, instead of trying to bond foam to the rubber tire, I wonder if there would be any value to securing sound dampening material to the rim itself (which is more acoustically reflective) via straps.

I wanted to go easy and buy the foam with the glue allready on it from Silent Coat. That sticks really extreme on almost everything... But again... I dont proceed this foam project. There are to many obstakels and I am not willing to take any risk on this.

Ill wait a few years. I'm sure that there will be some reliable "do it yourself" kits on the market or maybe all tires will have this foam in there standard.

 

[GSLex]

GSLex,

You're new here, so allow me to introduce myself. I used to work as an engineer for a major tire manufacturer. Among the things I did was answer questions that came through our 800 number or the internet.

You should be aware that when tires are manufactured, they put a mold release agent on the inside so the curing bladder releases when the tire comes out of the mold. That release agent needs to be removed to get anything to stick to it.

I do not know for a fact that Dunlop cleans the inside when they apply the foam, but I can not imagine anything else. I also do not know what might dissolve it (not a chemist.).

But I do know that certain chemicals will dissolve the innerliner. Among these are gasoline and brake cleaners. The only thing I am sure will not dissolve the innerliner is alcohol. I do not know how effective alcohol would be as a cleaning agent.

It appears to me that the mold release agent will be your biggest obstacle.

Hi Capri, thanks for the introduction and cool to see that you have worked as an engineer in the tire business.

I can imagine that there are greasy solutions on tires and I wanted to clean it with 96% alcohol since that seemed to be the safest in my view but like I said. I am not proceeding this project and decided to keep it original.

I hope when I go from 245 "foam tire" to a 225 "non foam" tire that this will fill the sound gap, because wider tires make more roadnoise then narrower tires.

Since you are working as an engineer maybe you can answer another question I've had for a very long time.
I have heard that the bigger the rim size the more roadnoise the car gets but what if you keep the width exactly the same when the car gets a lager rim? Let's compare between 18 and 19 or maybe even 20 inch. But again. We keep exact the same width.

I have called and written to all car manufacturiers over here and nobody could give me an answer on that because there are no engineers available to answer my question.

 

[CapriRacer]

............

Since you are working as an engineer maybe you can answer another question I've had for a very long time.
I have heard that the bigger the rim size the more roadnoise the car gets but what if you keep the width exactly the same when the car gets a lager rim? Let's compare between 18 and 19 or maybe even 20 inch. But again. We keep exact the same width.

I have called and written to all car manufacturers over here and nobody could give me an answer on that because there are no engineers available to answer my question.

First, there is much, .much more variation in noise levels between makes and models of tires than between different sizes of the same make/model. So the premise of your question is wrong.

Why would people think that larger wheel size means noisier tires?

Because when people upsize the wheels, they also go wider with a lower aspect ratio (in order to maintain the load carrying capacity - very important!). Lower aspect ratios = quicker steering response, and tires with lower aspect ratios tend to be high performance tires where noise can be sacrificed to get better performance, particularly wet traction.

So it's not the wheel size that is driving the increased noise. It's the increased performance levels of lower aspect ratio tires.

But to answer your question, if you keep the width the same, the noise level will NOT change - unless you change make and model. That's because it is easy to increase the length of an individual pitch length of a tread pattern (the part that doesn't repeat) to accommodate larger circumferences. Typical passenger car tires have 40 to 50 pitches.

It's harder to do width and keep the same tread pattern. Sometimes a rib will be added or subtracted. That's why you will find some models with both 4 rib and 5 rib (3 grooves/4 grooves) depending on the size.

The engineers at car manufacturers are not going to know this. To them, tires are a "Black Box" - that is, they want a certain performance level and they expect the tire manufacturer to deliver it, but they don't know themselves how to get it. That's probably why they didn't answer your question.

 

[GSLex]

First, there is much, .much more variation in noise levels between makes and models of tires than between different sizes of the same make/model. So the premise of your question is wrong.

Why would people think that larger wheel size means noisier tires?

Because when people upsize the wheels, they also go wider with a lower aspect ratio (in order to maintain the load carrying capacity - very important!). Lower aspect ratios = quicker steering response, and tires with lower aspect ratios tend to be high performance tires where noise can be sacrificed to get better performance, particularly wet traction.

So it's not the wheel size that is driving the increased noise. It's the increased performance levels of lower aspect ratio tires.

But to answer your question, if you keep the width the same, the noise level will NOT change - unless you change make and model. That's because it is easy to increase the length of an individual pitch length of a tread pattern (the part that doesn't repeat) to accommodate larger circumferences. Typical passenger car tires have 40 to 50 pitches.

It's harder to do width and keep the same tread pattern. Sometimes a rib will be added or subtracted. That's why you will find some models with both 4 rib and 5 rib (3 grooves/4 grooves) depending on the size.

The engineers at car manufacturers are not going to know this. To them, tires are a "Black Box" - that is, they want a certain performance level and they expect the tire manufacturer to deliver it, but they don't know themselves how to get it. That's probably why they didn't answer your question.

Thanks so much for this information. I have one last (to me) very important question.

When I take a bigger rim and I go from 16 inch to 19-20 of maybe even 21 (not that I like that but just for example) and I keep exactly the same sidewall hight or maybe even a higher sidewall, can I expect the same level of comfort or will I lose comfort?

 

[CapriRacer]

Thanks so much for this information. I have one last (to me) very important question.

When I take a bigger rim and I go from 16 inch to 19-20 of maybe even 21 (not that I like that but just for example) and I keep exactly the same sidewall height or maybe even a higher sidewall, can I expect the same level of comfort or will I lose comfort?

While this seems like a simple question, it is actually quite complex. that's because you are supposed to size tires such that the load carrying capacity is equal to or greater than what came on the car.

Plus, ride comfort varies according to make and model - and the range is quite large!

But let's assume we are working with the same make and model and the only adjustments are due to size.

So moving from a 16" to a 20" also involves going wider and with a lower aspect ratio - and that results in about the same diameter.

But if you add the requirement that you want the same sidewall height, then you will run out of fenderwell room.

So let's assume you don't have fenders and you can use almost any diameter tire, so you can keep the same sidewall height. Then there are 2 possibilities:

1) You adjust the inflation pressure downwards to maintain the same load carrying capacity.

OR

2) You keep the same inflation pressure.

In case #1, you will get a better ride, and in case #2, the ride will be more or less the same.

But don't forget that ride varies more than that depending on make and model. That is by far more significant.

 

[GSLex]

While this seems like a simple question, it is actually quite complex. that's because you are supposed to size tires such that the load carrying capacity is equal to or greater than what came on the car.

Plus, ride comfort varies according to make and model - and the range is quite large!

But let's assume we are working with the same make and model and the only adjustments are due to size.

So moving from a 16" to a 20" also involves going wider and with a lower aspect ratio - and that results in about the same diameter.

But if you add the requirement that you want the same sidewall height, then you will run out of fenderwell room.

So let's assume you don't have fenders and you can use almost any diameter tire, so you can keep the same sidewall height. Then there are 2 possibilities:

1) You adjust the inflation pressure downwards to maintain the same load carrying capacity.

OR

2) You keep the same inflation pressure.

In case #1, you will get a better ride, and in case #2, the ride will be more or less the same.

But don't forget that ride varies more than that depending on make and model. That is by far more significant.

Perfect information again. I wish we have talked a few years ago. That would have made everything way more easy for me.

I have asked so many people and specialists and nobody could give me the right answer.

Ow one more thing. The local company where I mount my tyres always tell me that when I mount a bigger rim that there is more risk of having vibrations in the steering wheel. The bigger the wheel the more sensitive it becomes.

Whats you'r opinion on that one?

Thats really the last question!

 

[Jetronic]

it's related to the lower sidewall height/increased inflation and vibrations generated by the road surface. It's not about the usual balancing