The Blue Painted Spot

[Pat]

Many know that our BFG tires come with a blue painted spot on the side walls. This is, according to those who know, the point on the tire that should line up with the valve stem. A sweet spot, if you will, that aids in the balancing of the tire.

Today, I asked the technician if he knew what that blue spot was. He did, I was impressed and went back to the waiting area. However, unknown to me the boss pulled him off the machine before he got to my tires and another person replaced him.

When I picked up the car I noticed that the blue spot was not even close to the valve stem and inquired why that was. That's when I found out another man had done the mounting. Oh, Snap.

I mentioned to the manager that all the tech's should be made aware of this feature. I don't recall seeing this on other tires but.....

Well, the tires are balanced but I'll always wonder if there isn't wobble in there somewhere.

[Zack]

Dont worry about it.

[Dragcity]

Gotta watch that theory. Some manufacturers mark the tires heavy spot, which would put the mark opposite the valve stem.

Or it could be a random stamp, so techs could see customers squirm......

[Bluerauder]

Many know that our BFG tires come with a blue painted spot on the side walls.

I have only gotten "red spot" BFG tires. Never have seen a blue spot. :P

[SILVERSURFER03]

thats interesting to know ..makes me want to go out and check mine

[Ken]

I have only gotten "red spot" BFG tires. Never have seen a blue spot. :PNo blue spot for the Bluerauder? :dunno:

Ken

[Egon Spengler]

Check to see how big the wheel weight is that they put on there... if it is a big one then maybe it isn't in the right spot... but itf it is a smaller one then that is cool.... eighter way you should be all set, that is why they make wheel weights... to balance out the tires... You be fine as long a there is no shimmy up on the highway or anything... If that spot is true and it isn't where it is supposed to be, then they just use a bigger wheel weight... putting the spot where the valve stem is might make them have to use a smaller weight making it more please to the eye instead of a big old weight on the side of your wheel

[wchain]

Its probably not a big deal that he dot isn't lined up, especially since they balanced the tire, however, I only recently noticed the blue dot. Historically they were red dots and yellow dots.

The yellow dot is the lightest spot and it is suggested to mount this above the valve stem.

The red dot is the high point, recommended to be mounted at the low point of the rim if so marked or, preferably, per actual measurement.


I need to figure out if this blue dot means something significant to why they're not using red and yellow anymore.

FWIW, the Tires I just put on the Contour had yellow and red dots.

[Pops]

Wes what colors do you use to make blue?

[Hotrauder]

Better to understand the G spot than worry about red, blue or yellow ones. Just sage advise from an old tire smoker. Dennis

[ckadiddle]

Better to understand the G spot than worry about red, blue or yellow ones. Just sage advise from an old tire smoker. Dennis
Now that right there is funny, no matter who you are. I strongly agree!

[Stranger in the Black Sedan]

Many know that our BFG tires come with a blue painted spot on the side walls. This is, according to those who know, the point on the tire that should line up with the valve stem. A sweet spot, if you will, that aids in the balancing of the tire.

Technically, the spot is for match-mounting. A spin balancer is used to find the imbalance of just the rim without the tire, and then the tire is oriented to minimize the number of balance weights needed.

The valve stem is not necessarily the location of the imbalance on a wheel. In all likelihood, it isn't.

[offroadkarter]

I have red and blue spots, they faded but they are still there.

http://i39.photobucket.com/albums/e185/offroadkarter/My%20Marauder/P8300040.jpg

[Professor]

When I changed tires, I was looking forward to getting rid of the set that I had because of the annoying blue spot. Now ... my brand new tires have the blue spot. How the hell do you get it off??? It looks band when you are trying to detail the car.

[Bluerauder]

I found the following on the Bridgestone Tire Site. Saw nothing on BFGs. Note at the bottom of the article that some manufacturers do not use the dots and others use different coding. Red dot (high point on tire) takes precedence over yellow dots (light balance point) Match red dot to the valve stem on Aluminum Wheels and on steel wheels without a low spot dimple on the rim. Ignore any other color dot. :D




ASK THE TIRE DOCTOR: Why are there all these strange dots on my tires?

What Do These Marks Stand For?

In a perfect world, you'd have perfectly round, perfectly balanced tires, mounted on perfectly round, perfectly balanced wheels, attached to perfectly straight, perfectly true-running axles.

But in the real world, nothing is perfect. No matter how hard manufacturers work to eliminate them, there are always variations in tires, wheels, hubs, bolts, axles, and every other part of a wheel end assembly.

And even if they come out of the factory in near-perfect condition, wear, damage, improper installation or poor maintenance can negate the manufacturer's efforts.

These variations can create what are called radial and lateral force fluctuations. Those are fancy words, but the result of either one can be ride disturbance, rapid wear, irregular wear — or all three.

Careful tire mounting using these marks can help you minimize these problems.

Some Of My Tires Have Red Dots. What Are They For?

When a tire spins, the amount of force it exerts against the road varies. In severe cases, the result can be a rough ride and wear problems. One reason the force can vary may be that the tire isn't perfectly round. It has "high" spots and "low" spots. (There are also lots of other reasons, which we'll explore in future issues of Real Answers.)

The difference between the high and the low is called radial runout. Using sophisticated computer analysis, Bridgestone engineers have found that a graph of the force variations looks a bit like a wave, as does a graph of the runout variations.

By simplifying the graphs to what is called their "first harmonic," it's possible to find the place on the tire where, on average, the force variation is greatest. That's where the first harmonic curve hits its high point.

And, it turns out that the first harmonic high point for the radial runout coincides pretty well with the first harmonic high point for radial force variation.

Now, wheels, especially steel wheels, tend to have the same kind of high and low spots as tires. In fact, many steel wheels are marked with a dimple that indicates their low spot.

So, if you could match the high point on the tire to the low point on the wheel, these forces would, to some extent at least, cancel each other, and you'd expect to get a smoother ride and maybe improved wear.

Some original equipment manufacturers are doing this kind of match mounting when they mount tires and wheels on new trucks. The tire is marked with a red dot at the high point, and this is matched with the low point dimple on steel wheels. On steel wheels without a low point dimple, and on aluminum wheels, the red dot is matched to the valve stem.

For a slight improvement in uniformity on steering tires, with hub-mount wheels, you can torque wheel nuts with the red dot at the "12 o'clock" position.

Carefully tighten one nut with a hand wrench before using the air wrench. Be sure the air wrench does not reposition the wheel.

What Are The Yellow Dots For?

Just as it's very hard to make a tire or wheel that's perfectly round, it is also very difficult to make tires and wheels that are perfectly in balance.

You can help minimize the amount of weight needed to balance a tire and wheel assembly by mounting the tire so that its light balance point is matched up with the wheel's heavy balance point.

All new Bridgestone truck and bus radials are factory- marked with a yellow dot at the light balance point. Generally, the heavy balance point of a wheel is at the location of the valve stem. This is true regardless of whether the wheel is steel or aluminum.

For best initial balance, match yellow dots to valve stems.

Which Dot Takes Precedence?

If a Bridgestone tire you're mounting has both red and yellow dots, the red dot has priority. Match it to the wheel low point dimple or valve stem. Ignore the yellow dot. Remember, "red rules."

Do I Have To Do Anything Special On Duals?

On dual assemblies, the best idea is to "clock" the two wheels so that their valve stems are 180 degrees apart. There are several advantages to this:

1. It makes air pressure maintenance easier.
2. Match-mounting tires and wheels puts the high points or balance points opposite each other, which helps counteract remaining imbalance or force variations.

What About Marks And Dots Of Other Colors?

On Bridgestone radials, only red or yellow dots are used in match-mounting. Ignore any other colors.

Does Every Tire Manufacturer Use The Same Marks?

Unfortunately, no. Some manufacturers do not mark their tires at all, and some use different colors. If you're not using Bridgestone radials, you'll need to consult your tire supplier for more information.

[Icarus]

Just to toss a wrench into this, different manufacturers use the dots for different reasons. That info Bluerauder posted is great for the Bridgestone tires though.

[Bluerauder]

Just to toss a wrench into this, different manufacturers use the dots for different reasons. That info Bluerauder posted is great for the Bridgestone tires though.
I noted that at the beginning of the article that the info was for Bridgestones and that I couldn't find comparable info for BFG. The end of the article also states ....



Does Every Tire Manufacturer Use The Same Marks?

Unfortunately, no. Some manufacturers do not mark their tires at all, and some use different colors. If you're not using Bridgestone radials, you'll need to consult your tire supplier for more information.