Technical Tyre Noise

[Adam1984]

My Panda is parked half on and half off a kerb overnight, every night. When I move off every morning there is a strange noise coming from the tyres that have been resting on the kerb, it sounds like a wobble board sound, any idea what is causing this?

 

[ZaphodB]

How old are the tyres ?

Check the 4 digit date code on each one ( on the side wall)

 

[Adam1984]

I have the brand Davanti all round.

And fronts are: 22 24, and 23 24

Backs are: 23 24 and 21 24.

 

[ZaphodB]

I'd try parking not on the kerb and see if symptoms continue .... does it continue for long?

Could be if the tyre itself is 1/2 on and 1/2 off you're deforming the tyre slightly , because you're halving the contact patch, and it takes a short while for the tyre to get used to full contact again...

 

[Adam1984]

I'd try parking not on the kerb and see if symptoms continue .... does it continue for long?

Could be if the tyre itself is 1/2 on and 1/2 off you're deforming the tyre slightly , because you're halving the contact patch, and it takes a short while for the tyre to get used to full contact again...

No it continues for about a mile down the road and then doesn't exist anymore.

I was thinking could be because they are not balanced correctly? Who knows

 

[ZaphodB]

Balancing problem wouldn't correct itself.

Rubber's obviously a natural product, the 'problem' is I'm guessing as I've mentioned in my previous post.

If the car sits 1/2 on, 1/2 off you're deforming the tyre, and it will take on a memory of that on that contact area, for a little while, which might exhibit as a balance symptom... until the tyre warms up , which is why it goes away..

I wouldn't worry about it, a different brand of tyre might exhibit slightly differently.

 

[ZaphodB]

I wouldn't worry about it, a different brand of tyre might exhibit slightly differently.

...apart from checking your tyre pressures are correct

 

[Panda IIs]

Have a read up on "compression set of elastomers" car tyres are generally made from synthetic rubber (not natural as implied above) but most elastomers have a level of compression set that is influenced by filler content too (which is used to manage wear and fatigue properties). Also as suggested, the tyres take up a set overnight that is removed as the tyre heats and takes a new shape. Also, an aside, the hysteresis of the compound influences the rolling resistance of the tyre, hysteresis is influenced by the fillers, all things are linked and a compromise of individual formulations (road noise another parameter).

 

[ZaphodB]

(synthetic rubber (not natural as implied above)

I was generalising

Modern day car tyres have about 15-20% fresh natural rubber composition.