Red Dot? Yellow Dot?

Springs, shock absorbers, wheels. Questions about this can be asked in this category.

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jifflemon
480 Is my middle name
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Red Dot? Yellow Dot?

Post by jifflemon » Thu Dec 09, 2021 12:11 pm

Came up in a conversation today, so I thought I'd share with you. As some of you know, I've a motor trade history, and without sounding all "misty eyed", back in my day, stuff like this was drummed into us before we were let loose on the tyre machine.

On the sidewall of most new tyres are red and yellow painted dots. If these marks are aligned with particular points on the wheel, you can reduce the amount of weight required for balancing. The less lead weight used, the lower the cost of wheel balancing for the garage and the better looking your wheels look.

The Yellow Dot
When tyres are made, they are almost never perfectly balanced, and most manufacturers will place a yellow dot on the section of the tyre where there is least weight. When fitting a tyre, they should line up this yellow dot with the valve stem as this is the heaviest point of the wheel. By aligning the lightest spot on the tyre with the heaviest point on the wheel, the tyre/wheel balance is as close to optimal as can be. So, they'll be fewer weights around the wheel to balance out the tyre and wheel.

The Red Dot
In the same way that tyres are never perfectly balanced from the manufacturer, tyres are never perfectly round either, even when new. They have high and low points which occur where the belts are joined, and these points can cause vibrations when a tyre is rolling. The red dot indicates the tyre’s high point. Sometimes a wheel will also have a dot—either a drilled dot or a sticker to indicate its low point; if you have these marks, you should align the red dot with the mark on the wheel and ignore the yellow dot. By doing this you minimise the vibration caused by the high point of the tyre

Red over Yellow
If both red and yellow dots are visible on your tyre and you don’t have any dots or marks on your wheel, red takes precedence over yellow and the red dot should be aligned with the valve stem. Cancelling out the high point takes precedence over the lightest point of the tyre, which can be addressed with wheel weights.

So, know you now and educate the tyre fitters!

yorkievolvo
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Re: Red Dot? Yellow Dot?

Post by yorkievolvo » Thu Dec 09, 2021 7:20 pm

And I thought fitting tyres to aircraft wheels could be awkward.

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dragonflyjewels
480 Is my middle name
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Re: Red Dot? Yellow Dot?

Post by dragonflyjewels » Thu Dec 09, 2021 8:14 pm

Well, that's a load of stuff I never knew. I'll bear it in mind in the spring when I replace Lily's tyres - they are still legal but I'm tired of not quite trusting the handling due to having three different brands, two of which I've never heard of. Ditch dumpers I suspect, but they were all practically new when they came with the wheels so I felt obliged to use them. Now I know there is still a market for second hand tyres I'll feel a lot better about binning them.
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo
hubby has
Sven - 1994 Racing Green GT
Evil Eva - 1992 Paris Blue Turbo

jifflemon
480 Is my middle name
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Re: Red Dot? Yellow Dot?

Post by jifflemon » Thu Dec 09, 2021 8:51 pm

dragonflyjewels wrote:
Thu Dec 09, 2021 8:14 pm
Ditch dumpers I suspect
Ah Chinese death circles, my favourite..... :rofl:

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dragonflyjewels
480 Is my middle name
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Re: Red Dot? Yellow Dot?

Post by dragonflyjewels » Thu Dec 09, 2021 8:53 pm

Be careful what you say Jeff, you might get a present ! :rofl:
Sylvia

Snazzy - 1993 Paris Blue ES red dipstick 2.0i bought 2001
Lethal Lily - 1991 White Turbo
hubby has
Sven - 1994 Racing Green GT
Evil Eva - 1992 Paris Blue Turbo

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dcwalker
480 Is my middle name
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Re: Red Dot? Yellow Dot?

Post by dcwalker » Fri Dec 10, 2021 9:16 am

Thanks Jeff - I've seen the dots often enough, but never given any thought to what they might mean, so this was all weirdly fascinating :lol:

David
Current: 1994 480 GT, 1995 Celebration 331 (plus 2013 V60 D5 SE Lux Nav & 1995 440 ES)
Previous: Celebration 467 (returned to Martin Mc); Celebration 346 (re-homed with Alan480); Celebration 269 (scrapped abandoned project), Celebration 73 (sold on after 6 years), 1992 ES, 1988 ES - and numerous other non-480 Volvos!

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