Red Spot on tires (paint or marker)

[Howie411]

So there is a Red Spot (looks like paint or marker) on my tires. These were on the car when I got it (had 40ish miles on it) I thought they would go away after a while but they haven't. Any idea what the point of it was and is there a easy way to remove it?

Edited January 29, 2014 by Howie411

[acdii]

Some tires are pre-balanced, and that red marker is used to point to where the valve stem should be located. Not may tire installers know that, I used to be a mechanic and did my fair share of tires. During a seminar with Cooper Tires i asked this very question and that was the answer I was given. Whenever I installed a tire from then on I made sure to line up the dot with the stem and the tires did balance with fewer ounces. Whether that is true of not for all tires, don't know, but it seems to be the case for the Coopers.

[hermans]

And here I thought it was the communication portal with the Mother Ship....go figure.

[Waldo]

Not all wheels are made to have the valve stem at the same point as the red dot. Most Ford wheels come into the factory with a little sticker on them at the "low point" of the wheel. The fancy computer mounting equipment matches the sticker on the wheel with the red dot (the high point of the tire) to minimize radial run-out. It's not really balance (mass related), it's geometry. Think of the wheel and tire as each being an egg-shape, not a circle. This matches the pointy part of the egg of the wheel to the opposite side of the pointy part of the egg of the tire. That's essentially what a road-force balance does as well.

 

If you see a car on a hauler on it's way to the dealer, you'll see the stickers on the wheels. But the dealer is supposed to pull them off as part of the pre-delivery preparation.

[Va2014HyTi]

Probably more than you want to know but here is some good info on the dots (from Bridgestone):

 

http://www.bridgestonetrucktires.com/publications/ra_v13_i1/PDF/ra_v13i1%20ask%20doc.pdf

 

Basically, "the red dot indicates the “radial force variation first harmonic maximum.” That’s a mouthful, of course, but it’s a way of indicating where the centrifugal force tending to pull the rotating tire away from the wheel is greatest. Another way of looking at it is that in a sense, if the tire were out of round, the red dot would more or less correspond to the “high point” or place where radial runout forces are greatest." You can read the Bridgestone document to see why that it is important to match the wheel's low point with the red dot.

[dalesky]

Probably more than you want to know but here is some good info on the dots (from Bridgestone):

 

http://www.bridgestonetrucktires.com/publications/ra_v13_i1/PDF/ra_v13i1%20ask%20doc.pdf

 

Basically, "the red dot indicates the “radial force variation first harmonic maximum.” That’s a mouthful, of course, but it’s a way of indicating where the centrifugal force tending to pull the rotating tire away from the wheel is greatest. Another way of looking at it is that in a sense, if the tire were out of round, the red dot would more or less correspond to the “high point” or place where radial runout forces are greatest." You can read the Bridgestone document to see why that it is important to match the wheel's low point with the red dot.

That's just what I thought! haha

[dalesky]

Not quite on topic, but I get little black dots of ? (grease maybe) on the front passenger wheel. They appear regularly, and are about 1/4 inch, on maybe half of the wheel. Exactly the same height all around the wheel. Not real easy to wash off either.

[hybridbear]

Probably more than you want to know but here is some good info on the dots (from Bridgestone):

 

http://www.bridgestonetrucktires.com/publications/ra_v13_i1/PDF/ra_v13i1%20ask%20doc.pdf

 

Basically, "the red dot indicates the radial force variation first harmonic maximum. Thats a mouthful, of course, but its a way of indicating where the centrifugal force tending to pull the rotating tire away from the wheel is greatest. Another way of looking at it is that in a sense, if the tire were out of round, the red dot would more or less correspond to the high point or place where radial runout forces are greatest." You can read the Bridgestone document to see why that it is important to match the wheel's low point with the red dot.

Fascinating info, thanks!

[SteveB_TX]

So there is a Red Spot (looks like paint or marker) on my tires. These were on the car when I got it (had 40ish miles on it) I thought they would go away after a while but they haven't. Any idea what the point of it was and is there a easy way to remove it?

When my Z was detailed before delivery to me the detail shop removed those stupid red dots. When my Mustang GT was delivered, they did not remove the dots. Point Lincoln! :) A squirt of 409 took them right off.

[acdii]

So the Cooper guy was only partially right. :)

[Waldo]

So the Cooper guy was only partially right. :)

 

Without the sticker, the valve stem is the next best guess.

Edited January 30, 2014 by Waldo

[Howie411]

Wow, you all are to funny, I now know way to much about tires. :) Back to the question at hand, has anyone actually removed them with over the counter stuff? I see 1 shout out for 409.

[acdii]

Blech White and a scrub brush is the best bet, also cleans the tires REALLY good.