New tyres and their radial markings

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wheels-inmotion

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Joined
May 18, 2008
Messages
727
Location
Hemel Hempstead
Car
Daily hog is a Vectra
Most fast fit centres/ fitters do not know what these markings mean, so be prepared for a "heads up".

Most branded new tyres will have coloured bands around the circumference, historically they are red/ blue/ yellow.

In most cases it's the red band that's of interest?

What does it mean?
During the tyres construction there is an unavoidable issue, this being the radial casing and the radial tread does not always perfectly align.

So what!
The tread being the friction point and the casing the support, a deviation between the two allows the tyre to deviate from the desired direction.

Meaning....!
This means the tyre can/ will steer the car if the steering is relaxed.

So...
The manufacturer measures the level of deviation and marks the tyre ( normally in a red radial line ) if the line is at the tyre's centre there's no deviation, the further the line moves from the centre toward the sidewall the more powerful the deviation.

What to do?
The lines are fitting instructions for the tyre shop but as said most are not even aware what they mean, so you need to be wise.

What's the instructions trying to say?
The fitter should read the lines and if off centre fit the front tyres with both lines "outside" or both lines inside, or to the "right", this either zeros the pull or pushes it into the road crown.

But i have directional tyres!!
That's not your problem. understand the reason and throw the problem back at the shop.

In summary
How many member here have had new tyres fitted and than experienced a pull?

Further reading
If you need images to visualize this topic you can find them in wim forum but you need to register to see them.

Hope this helps peeps....
Regards
Tony@ wim
 
Thanks Tony, useful info. Presumably with directional tyres they would have to be a matched (opposite deviation) pair?

Malc
 
Thanks. Had an interesting discussion in Costco Chester a while ago when they first insisted the bands didn't mean anything, then that they were OEM markings according to which car manufacturer the tyres where destined for!

They let me pick out the pair I wanted, but I think they genuinely thought I was mad.

The walls there are covered in the fitters' Michelin training certificates - perhaps they don't cover that bit!
 
Intresting read
 
Great information to know - Hopped through to the garage to check the new and as yet unfitted pair of tyres freshly delivered this week - Only one line (white) exactly on the centre line. :thumb:
 
Great info.. Could this be made a sticky post for future ref?
 
So...is that red line needs to be just to the outside of centre.......yellow dot next to valve ?? Or should I start reading from the top again :)
 
So...is that red line needs to be just to the outside of centre.......yellow dot next to valve ?? Or should I start reading from the top again :)

Read the link in post#4.
 

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