B arry's Tire Tech

This is a different approach to what I normally do on this website. I'm going to write a new entry every month covering whatever topics I discover during the previous month. I could talk about almost anything and I suspect some months I will have a lot to say and some months hardly anything at all!

With that in mind, here goes:

Oh, and the photo to the left? I was sent this by one of my many internet friends. The photo is one of his children playing with newly received tires. I thought it was one of the cutest things. I hope you find it as amusing as I did.


June 1, 2024:

I don't know why I didn't comment on this earlier, but the USTMA announced on March 29th that a consortium of 30 tire manufacturers have identified 6 possible alternatives to 6PPD, an antioxidant and antiozonant, used by almost every tire manufacturer and other rubber producers. 6PPD has been linked to salmon kills in the US Pacific Northwest.

The link to salmon kills was first reported in 2020, and efforts to ban the substance followed. The problem is the 6PPD is so widely used, so effective, and does not have good alternatives that a ban could cause major tire performance problems for consumers. It's been used since the 1960's.

I'm glad the USTMA organized the search for alternatives and I hope for a good outcome, but I think this is going to take quite a bit of time.


May 1, 2024:

I stumbled across a video on Formula 1 tires. YouTube: How are F1 Tyres Fitted?

It was hosted by Will Buxton (one of my favorites!) and conducted by Albert Fabrega (not a fan!). Albert is a technical expert for the F1 YouTube channel - not employed by Pirelli. Here's what I got out:

ALL the wheels are the same. They are made of magnesium by BBS. They are fitted with an FIA sensor and it appears no other sensors are allowed. The sensor is 180° opposite the tire valve.

The wheels seem to have an FIA specified wheel nut. That might explain why some of the teams have had trouble with them!

Each tire has a white bar code on the sidewall. They also have one on the side of the bead similar to some tire manufacturers do for passenger car tires.

They use conventional mounting equipment, but it is specially set up for F1 wheels and tires. Albert said they use a kind of glue on the beads and the rim seat, but I think he got that wrong. I think they use a paste-type mounting lube and they use that to minimize the amount they put on.

They inflate the tire on a separate unit. It took 2 psi to seat one bead and 26 psi to seat the other. They inflate the tire up to 60 psi, then deflate it down to 45 psi. They then scan the bar code and the data about mounting is encoded to a computer. They didn't say what gas they use, but I'll bet it is nitrogen and I'll bet that they can't use anything else!

It wasn't clear, but it appeared they only statically balanced the tire, because the tire only took 20 grams and they applied the weight to the center of the wheel.

When the weekend is over, ALL the tires are sent back to England. They didn't say where they were made (I looked it up - Turkey! and they seem to ship them from there to the race.) Albert said, they dispose of them by burning them to make electricity, but another source says they burn them to make concrete. Burning tires to make concrete is a common way to dispose of tires. I've never heard of anyone burning tires to make electricity.


Every so often I am confronted by the fact that I am a Geek - specifically a Tire Geek

I was looking at the latest issue of Tire Technology International and stumbled on an article about automated tire inspections. The article included a photo of a tire's load/inflation label - and it was wrong! Here let me show you:

It's the "AT" in the red circle. As a tire engineer I looked at the whole label and noticed that the max pressure is listed as 44 psi (300 kPa). That means, it's a standard load passenger car tire - and for those kinds of tires, the max load occurs at either 35 psi (242 kPa) or 250 kpa (36.3 psi), depending on whether the tire is specified according to The Tire and Rim Association (US based) or ETRTO (European based).

In either case. It is permissible to inflate the tire beyond those 2 values - and the other alternatives are 44 psi or 51 psi.

To my mind, the way to state this is either: "Max Load XXXX, Max pressure YY" OR "Max Load XXXX at 35 psi (or 250 kPa)". To do otherwise is misleading!

/end rant


In the Apr 8, 2024 issue of Tire Business, a trade magazine for the tire industry, there was an article indicating that "The Wheel Group", a company in California which distributes tires, has halted sales of its AMP brand non-mud-terrain tires because they didn't meet the US and Canadian standards for the Alpine symbol (aka 3PMSF). The tires did meet the European standard. As noted in my article on winter tires, there are 2 tests that can be used for the symbol. What I didn't know was that the US and Canada don't approve of the ABS braking test (aka UN ECE R117) . They only accept the ASTM F-1805 test. Interestingly, the company tested the tires using F-1805 and they failed! Apparently, they are planning on recalling the tires. I've updated my article to reflect the fact that the US and Canada only accept the ASTM test.


Also in the April 8, 2024 issue of Tire Business was an article indicating the Michelin had ranked number 1 in several JD Powers surveys of OE tires. I have a problem with these surveys. They are an add-on to the vehicle manufacturers on initial quality. These surveys are the standard within the auto industry. HOWEVER, the problem with tire portion is that there is a "Halo Effect" - that is, if a tire appears on a vehicle with a high ranking, then the tires tend to get a high ranking - and vice versa. Nowhere in the survey is this accounted for. Michelin is known for being very careful to make sure its tires go on potentially high ranking vehicles, and avoiding potentially low ranking vehicles. They do this by the price they offer the car manufacturers. They are not supposed to do that, but they play this game very well! The good news is that I don't think most people pay much attention to the JD Powers surveys.


In the Apr 22,2024 issue of Tire Business, a trade publication for the tire industry, Pam Oakes pointed out that 5 states do not have any tread depth minimums! They are Montana, North Dakota, Arkansas, South Carolina, and West Virginia. It should be noted that the Federal government is not allowed to specify this, but they can specify what the tire manufacturers do during the manufacturing process - and they do. They currently require an indicator when the tires reach 2/32nds of an inch (1.6mm).

She also noted that some states require 4/32nds.


Stumbled across a YouTube video where Michelin was unveiling its latest airless tire. The video said that Michelin expected to have a tire marketed within the next year. The problem is that they have been saying that for 30 years. There are technical issues that don't seem to be solvable.


I got a notice of a recall by Goodyear of 82 tires for - get this - not having a date code.

This does not affect how the tires would perform. I get that the tires aren't compliant to the regulations, but "Really?".

I suspect this is NHTSA exercising their regulatory muscle and I suppose they needed to do that to make sure tire manufacturers are paying attention.


April 1, 2024:

Tire Business reports that 6 tire manufacturers have been sued in a class action civil lawsuit in both New York and California for price fixing. They are Bridgestone, Continental, Goodyear, Michelin, Nokian, and Pirelli. This is on the heels of the EU raiding 5 out of the 6 for antitrust activities - Goodyear, not being raided. I suspect I'll have to write an article about how I think tire pricing works.


I am writing this the day after the NASCAR Bristol race and it was all about tires!

First, enough tires were worn to the cords that I could tell some things about the actual construction of the tires - namely the tires have a single circumferential cap ply, the belts aren't steel (probably Kevlar). I'm not sure about this, but it maybe that there was only one belt. This doesn’t make sense to me, but I think it might be possible, albeit with a lot of plysteer. (See my webpage on Force and Moment.)

If you didn't watch the race, the tires were wearing pretty fast because the track surface (concrete) was not "rubbering up" - meaning the rubber wasn't getting imbedded into the macrotexture of the track so that at least part of the surface the tires was running on was the rubber being abraded off the tires, which is what normally happens. It appears that everyone was surprised by this. NASCAR wound up releasing another set of tires to the teams to make sure the teams had enough tires to last the race. (They started out with 9 sets, plus a set from qualifying, plus the set from NASCAR, for a total of 11.)

What happened was that the cars were capable of running much faster at the expense of tire wear, and you could burn off the right side tires in a few laps - either the front or the rear, depending on how the car was handling.

If I were Goodyear, I'd be assigning the fix to the rubber chemists. To my eye, the compound was too dry (You should take this with a huge dose of salt, because rubber chemistry is a weak point for me.)

HOWEVER, it made for a very interesting race. It challenged the drivers and the crew chiefs in ways they never imagined they'd be. I hope Goodyear doesn’t change things too much because the sight of a front runner suddenly dropping back because he burned off his tires really spiced things up!!

March 1, 2024:

Apparently India limits the imports of tires to its market. The latest is that they have now added 70 tire make/models to their mandatory quality standards and taken them off the exempt list. I don't understand how this works.


Tire Business reports that Bridgestone is suing Apollo tires over the use of the name "Pinza". Bridgestone claims that the use of names ending in "nza" are characteristics of BS tires citing Potenza, Turanza, and Alenza as examples - and that this name creates confusion. BS brought a case before over the name Milanza by Federal Tires. BS lost in the lower courts, but won on appeal. I find this fascinating, but have no idea how this will play out.


The European Commission raided tire manufacturers Bridgestone, Continental, Nokian, Michelin, and Pirelli claiming antitrust activities. I don't know what to make of this. It is interesting who was not raided - Goodyear. Tire Business intimated that whistle blowers can get beneficial treatment for such activities.


One of the problems I didn't anticipate when I started writing this blog was having to backtrack - fill in the details of some past issue so I could do an update. This next one is such an issue.

The Washington state legislature adjourned without acting on a piece of legislation that would authorize their commerce department to set rolling resistance standards for tires sold in the state. That means the issue is dead and won't be acted upon unless a new bill is proposed at the next session. I doubt that will happen.

So here's the background:

A bill was proposed in the state of Washington that would authorize their commerce department to require the publication of tire rolling resistance for tires sold in the state and to potentially set minimum standards. This proposal sounds very much like what the state of California has proposed, but California is very much ahead of Washington in the process.

The California Energy Commission (CEC) has proposed a regulation authorized by a law passed by the California legislature. The proposed regulation was announced in February, 2023 and comments solicited. The USTMA (US Tire Manufacturers Association) commented that the proposal would eliminate 99% of the current tires being sold and was therefore unworkable. The USTMA has subsequently supplied the regulators with data to help the regulators understand the issues. That was 6 months ago.

I suspect the CEC will abandon the effort.

In the meantime, NHTSA (National Highway and Traffic Agency), the US federal agency the sets tire regulations has said they will issue a rule for consideration in June, 2024 - HOWEVER - they have said they would do this starting in 2009, and keep kicking the can down the road. I expect that to continue.

I go into more detail here: Barry's Tire Tech: Draft Framework of California's Replacement Tire Efficiency Program


A friend of mine - Roger Marble - published a new post on his website RV Tire Safety:

RV Tire Safety The one dated Jan 24, 2024. I don't know why it took me so long to notice it.

But here's the thing: Roger and I have had a conversation on this issue and I decided not to pursue the point.- letting my webpage serve as my rebuttal. There's a part of me who wants to comment on the post, but I don't think it will serve the greater good.

In essence our difference is over what actually holds up the load in a tire. I wrote up a whole webpage on the subject: Barry's Tire Tech: Footprint. Roger is stating it's the air pressure, not the sidewalls - and I state it's the sidewalls and the pressure stiffens the sidewalls. But I see his point. He's saying that folks should not judge a tire by the stiffness of the uninflated sidewall - and he's right!!

The inflation pressure has way, way more effect. For example, a RunFlat tire has a really stiff sidewall - much stiffer than a conventional tire - and you only get a bit more harshness and no more load carrying capacity.

So in the big scheme of things, he is emphasizing that inflation pressure is very, very important - and much more important than the sidewall construction. I am not going to dilute his message.

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