tyres

[james butler]

ive just found out that new tyres usually come with a yellow and sometimes red dot on them to denote lightest and heaviest spot so it can be fitted in relation to the valve for best balance.
i never knew that before, how many of you did?
learn something new every day

 

[gordon stephenson]

I always knew this, BUT tyre fitters in my experience usually do not take any notice, You have to keep an eye on them virtually every time.

 

[Melvyn Best]

The red mark is the highest radial run out and if the wheel rim is marked they should line up

 

[m_c]

It depends on the manufacturer.
Some cheaper brands use a yellow dot for "quality control"

 

[Pigeon_Droppings2]

One of my pet hates....tyre fitters who don't know and then slap a load of extra weights on the rim!

The dot should be fitted close to the valve...or is it opposite...I can never remember!

Very annoying when it's not lined up.

It's one of those things you discover and then wonder how you never knew. Like the time I discovered why every tape measure has a loose rivet holding the tab on...

 

[armalites]

Yellow dot is for weight based balancing and marks the lightest point of the tyre so should be placed next to valve. Red dot is for uniformity balancing and is the point of highest radial runout. The red dot is only used on wheels that have radial run out markings.

All explained here
https://www.yokohamatire.com/tires-101/advanced-information/match-mounting

Most tyre places don't have the time or inclination to do it properly. I've spent up to an hour messing around trying getting wheel that needed loads of weights balanced by rotating the tyre or flipping it or even swapping to a different wheel. My balancer has a split weight program so you can hide the weights behind the nearest spokes, I've never seen a tyre bay do this ever.

 

[armalites]

One of my pet hates....tyre fitters who don't know and then slap a load of extra weights on the rim!

The dot should be fitted close to the valve...or is it opposite...I can never remember!

Very annoying when it's not lined up.

It's one of those things you discover and then wonder how you never knew. Like the time I discovered why every tape measure has a loose rivet holding the tab on...

Some wheels are a nightmare, you do the test spin then fit the exact weights and test spin again and they'll be 10g out. I've seen many wheels with weights directly opposite each other on a rim, normally older stuff with tubes though. When that happens I just take them all off and start again.

 

[armalites]

You would be surprised how hard it is to get that yellow dot lined up with the valve as the tyre moves during mounting. With stiff side walls it's difficult to rotate even with the lube. As soon as you move it it goes too far. As far as I'm concerned if you are going to do it you get it perfectly lined up.

The problem when you have spent a lot of time playing with this stuff is the amount of wheels you see that have been done badly.

 

[tigdlo]

How do you know the valve with be the heaviest or lightest point of the rim? You don't, I have spun up a few bare wheels with and without valves and found no correlation.

Should tyre fitters would check the balance and runout of a wheel before fitting a tyre? I don't think so. There is usually a maximum permissable weight for balancing specified by manufacturers, if you can find it. If your wheel is in good condition it won't matter where you put the tyre.

Some wheels are a nightmare, you do the test spin then fit the exact weights and test spin again and they'll be 10g out. I've seen many wheels with weights directly opposite each other on a rim, normally older sutff with tubes though. When that happens I just take them all off and start again.

If the weights are on opposite faces too, thats not too uncommon but if there are the same face, the weight probably needed moving around the rim a few inches then trying again.

 

[armalites]

How do you know the valve with be the heaviest or lightest point of the rim? You don't, I have spun up a few bare wheels with and without valves and found no correlation.

Should tyre fitters would check the balance and runout of a wheel before fitting a tyre? I don't think so. There is usually a maximum permissable weight for balancing specified by manufacturers, if you can find it. If your wheel is in good condition it won't matter where you put the tyre.


If the weights are on opposite faces too, thats not too uncommon but if there are the same face, the weight probably needed moving around the rim a few inches then trying again.

The problem with spinning a bare wheel is the software is working on the assumption of a tyre being in place. I done the same. I would say the best you are going to gain from lining the dot is maybe not fitting weights at all. The other thing is once you've done a few thousand miles all that goes out the window. That said if it doesn't take too long there is no harm in doing it, at least it looks like you thought about what you were doing. To me it's the same as lining up the screws on electrical installations, most people will never notice but it takes no extra time.

I really like fitting tyres and balancing but I'm not doing it full time. A friend of mine swapped the centres on some wheels for his hotrod, one of them out of alignment. I managed to balance so he had no vibration at all. He said he couldn't believe it, it wobbled that bad that he couldn't even look at the wheel because it was make him feel ill

 

[Migmac]

I knew.

 

[Barking Mat]

That's interesting, learn something new everyday, thanks @james butler .

 

[My Old Landy]

I just had two new tyres on the front and both had the red dot lined up with the valve

 

[hotponyshoes]

How do you know the valve with be the heaviest or lightest point of the rim? You don't, I have spun up a few bare wheels with and without valves and found no correlation.

Should tyre fitters would check the balance and runout of a wheel before fitting a tyre? I don't think so. There is usually a maximum permissable weight for balancing specified by manufacturers, if you can find it. If your wheel is in good condition it won't matter where you put the tyre.


If the weights are on opposite faces too, thats not too uncommon but if there are the same face, the weight probably needed moving around the rim a few inches then trying again.

The idea is the wheel manufacture spins the wheel up once it is made and dripls the hole for the valve at the heaviest point.
Don't know if they all do it though?

All the years I have had tyres fitted they have just chucked them on wherever they land. Once or maybe even twice they have shown an error when put on the balancer and they pull the tyre off, rotate it 180deg and whack it back on the balancer again.

I only really run trucks and vans so as long as the steering wheel does not shake I'm happy.

I do have a seven style that goes on the track once in a blue moon and I got a old boy to balance the toyos with a manual bubble type for that (and filled them with nitrogen)

I think I would need to be a much better driver to notice any performance benefits from the dots matching the valves...

 

[armalites]

filled them with nitrogen

I run a 78% Nitrogen mix in mine

 

[Migmac]

I was trying think how I knew. It came to me. When i worked for the private forestry sector, we had our own vehicle workshop. The mechanic was fitting new tyres to my SJ413. He fitted them on the rims with the dots opposite the valves. He explained it to me as he did when I asked any question. Great guy, if you were interested he had time to explain things to you. As young man I found it all interesting. It helped that I took scotch pies and donuts in, even if I wasn’t needing anything done

 

[bricol]

I run a 78% Nitrogen mix in mine

Me too. In all my cars. And push bike. Even filled the g/f's Fiesta tyres with it. She never mentioned if she could tell . . .

 

[Cobbler]

Me too. In all my cars. And push bike. Even filled the g/f's Fiesta tyres with it. She never mentioned if she could tell . . .

Tell her there’s a small amount of rare gasses in there as well ..... but she’s worth it

 

[Westfield-builder]

I run a 78% Nitrogen mix in mine

Isn't that just fresh air ??

 

[roofman]

I run a 78% Nitrogen mix in mine

load of rubbish that in road cars and bikes...i measured my bike tire one summer morning before a ride out and with normal council estate air it only increased pressure by 3 psi on a hot afternoon with sticky tires....snake oil imho but having said that if someone buys it and uses it then that's fine too