FASTdan
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| posted on 11/7/10 at 10:01 PM |
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Radial Run-out on a tyre?
Can anyone tell me what the accepted allowance for radial run out on a new tyre would be?
I've had 2 new avons put on the front of my mondeo ST TDCI. I immediately noticed a slight vibration at 80mph and worse under braking from that
speed. I took it back and they checked the balance and said nothing was wrong.
I have now had a dial indicator on the tyre and found a 1.5mm flat spot on both tyres. Passenger side flat spot covers about 1/8th of the
circumference and the drivers about 1/4 so they are quite noticeable - with the rest of the tyre only deviating about 0.5mm max.
Both rims are spot on radially and axially. Likewise discs are within 0.1mm max (thought I'd rule these out whilst I was at it).
I'm struggling to find much info on actual values for run out so just wondered if anyone could clarify whats acceptable? I've seen
0.05" (1.27mm) quoted on one site.
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http://www.danstengineering.co.uk/
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Canada EH!
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| posted on 12/7/10 at 01:12 AM |
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Sounds like they were not stored properly, take them back that flat spot is too big.
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snapper
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| posted on 12/7/10 at 05:40 AM |
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Also email the manufacturer if they say they have been stored wrong you can show this to the retailer
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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britishtrident
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| posted on 12/7/10 at 07:07 AM |
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Its a manufacturing error I have seen this before on Avons --- these tyres should have been stamped "RQ" and sold as seconds
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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Mal
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| posted on 12/7/10 at 07:12 AM |
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The tyres could be balanced correctly according to the balancing machine, but the eccentricity of rotation could still produce an excitation vibration
force you can feel as you drive.
Don't be fobbed off but the supplier.
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jossey
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| posted on 12/7/10 at 08:40 AM |
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i bought some sunew tyres which i had issues with. i get speed wobble at 70 mph for the first 5-10 mins i drive it when its been stood for more than 1
day.
by the time i get it to garage they are roudn again. pain in arse.
lol
If they put it on the balancer and line a bar up with the top of the tyre they will be able to see the flat spot and if they line up the rim they will
bar they will see the rim is fine.
sales of goods act will cover this fault.
dave
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britishtrident
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| posted on 12/7/10 at 08:59 AM |
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quote:
Originally posted by jossey
i bought some sunew tyres which i had issues with. i get speed wobble at 70 mph for the first 5-10 mins i drive it when its been stood for more than 1
day.
by the time i get it to garage they are roudn again. pain in arse.
lol
If they put it on the balancer and line a bar up with the top of the tyre they will be able to see the flat spot and if they line up the rim they will
bar they will see the rim is fine.
sales of goods act will cover this fault.
dave
The cause is parking the car when the tyre carcass is hot.
This used to be a common problem in the 1960's when the Dunlop X ply high speed tyre used Nylon reinforcement. Rootes fitted these tyres to
Sunbeam Alpines and Tigers and issued a Service Bulletin on the problem. The official cure I jest not was to drive the car at high speed for 5
minutes then at a much lower speed for 10 minutes to allow the tyre to cool down before parking.
If a modern tyre is getting hot enough for this to happen I would suspect the tyre pressure is too low. Get the tyre warmed up then pump say 5 psi
more air in, and see if the symptoms improve.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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jossey
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| posted on 12/7/10 at 11:02 AM |
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thanks for that ill give it a go.
quote:
Originally posted by britishtrident
quote:
Originally posted by jossey
i bought some sunew tyres which i had issues with. i get speed wobble at 70 mph for the first 5-10 mins i drive it when its been stood for more than 1
day.
by the time i get it to garage they are roudn again. pain in arse.
lol
If they put it on the balancer and line a bar up with the top of the tyre they will be able to see the flat spot and if they line up the rim they will
bar they will see the rim is fine.
sales of goods act will cover this fault.
dave
The cause is parking the car when the tyre carcass is hot.
This used to be a common problem in the 1960's when the Dunlop X ply high speed tyre used Nylon reinforcement. Rootes fitted these tyres to
Sunbeam Alpines and Tigers and issued a Service Bulletin on the problem. The official cure I jest not was to drive the car at high speed for 5
minutes then at a much lower speed for 10 minutes to allow the tyre to cool down before parking.
If a modern tyre is getting hot enough for this to happen I would suspect the tyre pressure is too low. Get the tyre warmed up then pump say 5 psi
more air in, and see if the symptoms improve.
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FASTdan
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| posted on 12/7/10 at 04:05 PM |
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thanks for the advice guys. ive emailed avon but they wont comment - was hoping for some ammo before returning to the fitters. anyway i'll be
taking them back tomorrow.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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