Tires Deformed

[TheGoodDeal]

Last few days I feel my car vibrating up and down every half second at slow speed (under 50 Km/h). It's OK at high speed. I suspect it hit some nails or something wrong with the hub bearings. I jack up the car and check all the wheels and found out one of my rear tire litle bit deformed. It's not perfect round. The outer circle of the tire went up & down a litle bit when I spin the wheel. Is it safe to drive with the tire like that? I plan to change rear tires within another 6 months. It still has about 3mm tread left.

[j.meng87]

When you say outer circle, do you mean the sidewall? If yes i'm guessing you have a tyre bulge problem. This is very bad as the tyre can blow up while driving. Change that tyre with a spare wheel if you need to drive

[SiReal]

how is the actual alloy? are the current tyres properly speed rated and load rated to your cars specs?

if u have no idea what i'm talking about, take it to a tyre shop.

[DLO01]

If the tread is at different depths around the tyre (not across the tyre). The wheel/tyre may be out of balance. Get it fixed.

[TheGoodDeal]

Thanks for the replies!! It's not the side wall. The outer circle I mean is the flat sure face that contact the road when it rolling. I can see and feel with my hand it's not even flat. It just happen a few days so the treads depth still the same around the tire. It has been fitted for many years. It's stock size 175/65/R14, as I remember the rating is 82H and the year it made week 51 of 2000. I believe the tire too old so the rubber become harden, so when the car hit poth holes and it not spring back to original form. Also I think the alloy wheel (rim) still OK and I alway inflat it 38-40 PSI.

[panda[cRx]]

from the sounds of it your tyres are 'scalloped'. it's actually relatively common but most people dont realise (or dont check their own tyres enough)
from what i hear there is no set reason why it happens, as tyre manufacturers blame the car and car manufacturers blame the tyres.

it'll be fine to drive but you will have increased road noise. the only way to fix it is to replace your tyres. some tyre suppliers believe certain tread patterns are less prone to scalloping so ask your tyre supplier when you get them done

[JohnL]

The tyre is in the process of delaminating. Air is getting from inside the tyre to between the belt layers or between the belts and the outer tread and causing it to bulge as the area of delamination gets larger and larger. It's dangerous, like very dangerous. The risk of blow out is real, though if you were lucky it might just slowly deflate when it fails, and it will fail. Blow out is not unlikely to involve throwing a tread. Change it now.

[TheGoodDeal]

Thanks Panda, you are right. It look like 'scalloped' or multi oval shapes. JonhL, your explanation is sound technically correct, but there are not any bulge (lump) I can see yet. The tire it's just not perfect circle.

[SiReal]

For a replacement tyre that is dirt cheap for that size, with only 3mm of tread left, there is no reason why you should not buy a set of new and safe tyres :)

[TheGoodDeal]

Yep, I'll replace rear tyres them ASAP. I just replaced the front with Pirelli Dragon 175/65/R14 for only $95 each six months ago. Thanks all

[JohnL]

Thanks Panda, you are right. It look like 'scalloped' or multi oval shapes. JonhL, your explanation is sound technically correct, but there are not any bulge (lump) I can see yet. The tire it's just not perfect circle.

Just sounded like a delaminating tyre from your description. Have you locked the brake severely recentyl? Sounds like maybe a 'flat spot'??

[TheGoodDeal]

No, I didn't hard braking recently. So there are not any flat spots. The tyre's outer circle look like warped. ie the inner shoulder is higher then the outer shoulder at some sections and then opposite at some other sections (the treads still have the same depth).

[JohnL]

It sounds like the sort of severe wear you might get with worn suspension components and poor alignment. I'd have it checked out before you allow your car to eat a new set of tyres...

[TheGoodDeal]

I believe it not cause by worn suspension or pure alignment because the treads depth still the same around the tyre. I'm just check again this afternoon. The areas higher then surround areas are softer when I try to press it. Also I saw alot of very fine cracks on corner of outer layer and side wall at those areas. So as you said "The tyre is in the process of delaminating. Air is getting from inside the tyre to between the belt layers or between the belts and the outer tread and causing it to bulge as the area of delamination gets larger and larger." The tire too old (more then 7 yrs) the rubber has been deteriorated.

Anyway I'll go to tyres shop to check it out tomorrow (tyres, suspension, alightment).

[TheGoodDeal]

Update: I went to Jaxquickfit. They said "the problem is treads separating and can't drive with something like that, treads will come off soon". Two new tyres fitted. Everything sweet now after the test drive.

[SiReal]

nice, what tyres did u get??

[TheGoodDeal]

175/65/R14 Pirelli Dragon $95 each, the same price i did change the other two 5 months ago. They are now so quiet & very good grip.

The funny thing is last time when I change the other two tyres. They did wheel alightment and didn't charge for it. So I was though I got free wheel alightment. This time when I ask "Is it come with wheel alightment?" They said "No" and I said "I got free wheel alightment last time" then they said "they never did offer free wheel alightment when bought tyres"