Anyone had experience with Grid 2 Tyres "cupping"

Kl Gtvi 2003 Verada. On my second set in 80000 klms.

Left rear cupped around 20000Klms. Rotated to front at 25000Klms to even out wear and eventually got 52000Klms out of all 4 tyres. Albeit with the dreaded rumble from front left (cupped) tyre!

Had tyre retailer check rear suspension when purchasing second set who reported all was well and stated that there were no obvious faults but that low profile tyres can be prone to "cupping".

Also had Mitsi dealer check over suspension at next service. No problems found.

Second set of Grid 2s quiet until 75000Klms when rumble starts in left rear again. At 78000Klms rotate fronts to rear and now looking forward to next 25000Klms of tyre rumble (Sounds like a faulty wheel bearing but is not!). Not happy having spent $1000 plus wheel alignment on these four tyres.

Apart from worn shocks, misaligned suspension or excessively hard braking (All ruled out) does Anyone know of causes/fixes for this problem or should I look at a different brand of tyre when these wear out.

A check of other Magna/Diamante forums indicates others are having similar problems.

Looking for input from Anyone with technical knowledge on the subject.

Cheers

By cupping do you mean bubbles forming between the laminations in the tyre? If so the should be replaced by the manufacturer.

By cupping do you mean bubbles forming between the laminations in the tyre? If so the should be replaced by the manufacturer.

No, cupping is balding of tyre tread in cicular patterns (like a bald patch on a balding man's
head).

Causes can be unbalanced tyres and wheel assemblies and lack of rotation. Tyres should
be rotated every 10000kms.

Cupping was explained to me by tyre people as raised blocks of tread in opposite direction to rotation of tyre.

If you run your hand over the face of the tread in the direction of rotation you can feel the raised areas of tread. (your hand pushes up against the raised areas)

Visual inspection of the tyre shows no strange or uneven wear other than the raised tread blocks.

NB With both sets of tyres only one tyre on each occassion has been affected. Left rear!

Tyres have always had recommended 36PSI pressure.

Cupping was explained to me by tyre people as raised blocks of tread in opposite direction to rotation of tyre.

If you run your hand over the face of the tread in the direction of rotation you can feel the raised areas of tread. (your hand pushes up against the raised areas)

Visual inspection of the tyre shows no strange or uneven wear other than the raised tread blocks.

NB With both sets of tyres only one tyre on each occassion has been affected. Left rear!

Tyres have always had recommended 36PSI pressure.

From tyres manufacturing sites, cupping was explained as I stated above.

Have you ever braked hard enough to activate the ABS because what you described above
sounds like the tyres were skidding in those spots when braking, which means the abs
isn't working as it is supposed to on the left rear wheel.

Sounds like flat spotting your tyres. I.e. loosing traction and skidding sidways away from the tyre rotation. Would explain it if you are driving hard around the corners.

Get a better wheel alinger! and the twits at Mitsu wouldnt have a clue. Your left rear probably has too much camber and is scalloping the tyre. Try to find some one who aligns cars all day, if you are lucky, he might know what he is doing. Most wheel alingment machines have "stock" measurements for factory settings, but if you or the previous owner have hit a major bump it may have moved the whole rear cradle, get it on a hoist and have a GOOD look at all the rear cradle mount rubbers, see if any have moved, also get someone to follow you on a flat, level road and see if your car actually drives straight and dosent "crab".
Hope this helps!

Being in the tyre game, we call it scalloping, usually due to lack of rotations (should be done every 10k). It was a big problem with second gens. (no rear adjustment) even Mitsys sent out a press release on cross rotations. The left rear tends to get it worse. Every front wheel drive gets it. All you can do is keep the rotations up and do four wheelalignments regulary. It may help to loose the directional tyres so you can cross rotate.

Interesting, I have 17" Grid II's that have been fine. They have clocked up 75000km and are just about due for replacement. I rotated them front to rear once, at around 40-50000km.

However, somebody I know has a TL AWD with 16" Grid II's is having the same problem. The car only has 20,000kms on it and one of the rear tyres (which has now been rotated to the front) is producing a noticeable rumble noise. Also the tyres feel like they are wearing with a raised lip on one edge of the tread block. Is it the car, or the type of tyres, or both?

I had 16" Grid II's on my VRX AWD, they started to rumble in the rear (probably at ~30,000km). I asked the dealer about the noise, they said that they had seen it before. I had the dealer do a rear wheel alignment, it didn't help. They said not to rotate the tyres as the tyres from the rear would get noisier in the front. I had the local tyre place do another rear wheel alignment, it may have helped a bit, but the noise was still there. I did my own rotate a few weeks back at and noticed that the front tyres were bald on the inside... so much for dealer servicing, they should have noticed and told me an alignment was required. So I had to replace the set of four at 46,000 km.

So, for the noise, I wouldn't get Bridestone Grid's, and for the wheel (mis)alignment, I wouldn't trust my dealer service dept.

I choose Yokohama A-Drive's for their alleged good wet weather handling, but they tend to be "squirrelly" around wet, sharp corners.

Ken