Tyre protector question

[savi18]

Just been reading on the forums about Tyre protector fitted to front springs. Is this year related as I have 1999 v6 model. Looks like vehicle's after 2004 are affected. Cheers

[Lord of Hog]

It cost me a tyre on my 2000-plate V6 so it's worth thinking about fitting them. There's a bit of an ongoing debate as to whether or not the fixings are actually up to the job, but that's another story.

[Mike Noc]

Every little helps, so I believe they are worth fitting - cheap and easy enough to do.

As regards how good they are; on my car which was part of the recall (X reg) three front spring breakages which were all contained, Mrs Noc's 75; one breakage and spring through the tyre, the new aquisition; one breakage spring hit tyre but wheel swapped for a space saver to get it up on the drive, so tyre saved.

Needless to say, all of the fleet are now equipped with spring protectors.

[T-Cut]

Here's a comment I kept from a member who was involved with the development of these gizmos.

I spent a lot of time driving over kerbs and pot holes with cut springs developing the tyre protectors. I agree they do not catch everything but they do stop most. We changed the spring manufacturer in the end to cure this problem.

It's nearly impossible to design and test a product that would catch everything with the package constraints that we had. I cannot remember exactly when, but the spring supplier changed mid/late 2002 so later cars should not suffer from the spring break problem as much. You can never eliminate spring breakage completely as it is a high stress component and a small stone chip will cause a stress point which could fail eventually.

Spring fracture happens to every car make, old and new. It's also more prevalent during the winter months, when low temperature embrittlement plays a part. It's initiated by corrosion in the main.

This is my copy of a graph published by the AA a few years ago.



TC

[rab60bit]

Originally Posted by T-Cut

Here's a comment I kept from a member who was involved with the development of these gizmos.

I spent a lot of time driving over kerbs and pot holes with cut springs developing the tyre protectors. I agree they do not catch everything but they do stop most. We changed the spring manufacturer in the end to cure this problem.

It's nearly impossible to design and test a product that would catch everything with the package constraints that we had. I cannot remember exactly when, but the spring supplier changed mid/late 2002 so later cars should not suffer from the spring break problem as much. You can never eliminate spring breakage completely as it is a high stress component and a small stone chip will cause a stress point which could fail eventually.

Spring fracture happens to every car make, old and new. It's also more prevalent during the winter months, when low temperature embrittlement plays a part. It's initiated by corrosion in the main.

This is my copy of a graph published by the AA a few years ago.



TC

Just to repeat a more plausible explanation of the apparent "low temperature embrittlement" theory which doesn't add up with the metallugy unless you get down to the region of -100C and lower.
More likely however - springs develop small macro fractures due to exposure/corrosion and stressing; in cheaper spec. heat treated steels this manifests as minute surface flaking and 'nicks/pockets'.
Moisture abounds and justs help the general corrosion along but in cold weather, particularly when the ambient temperature reaches 3C or dives lower the trapped moisture freezes and turns into ice. The springs meanwhile continue to stress and undergo torsion and all the tiny pockets of trapped ice act like mini wedges - yup, you've guessed it, the micro cracks get bigger and bigger causing larger cracks etc. etc. Ever increasing changes in cross-section of the steel thus brings higher and higher stresses resulting in the eventual classic 45deg. shear fracture to the whole spring cross section.
Better, controlled quality spring steel (and better coating of the springs) will slow down the process.

[T-Cut]

Originally Posted by T16

I fitted them once, and thought they were a total and utter waste of time.

Did you have a spring fracture? What were the circumstances?

The screws screw into the shock spring cup drain holes!! Meaning water is going to collect in the bottom of the shock.

I don't think they were drain holes, being of different sizes and not in the best location for drainage. They sit either side of a one inch vent hole. Some struts didn't come with any small holes and required drilling to fit the plates.

Moreover, the actual height of the protectors, really didn't seem to be high enough to mitigate against serious failure.

The MGR engineer testing them on dozens of weakened springs said they stopped 'most' fractures from damaging the tyres. I guess that's better than nothing.

You'd think at the age the cars are now, most of them would have had the front springs replaced these days anyway?

Spring fractures are happening all the time to all car makes (see diagram). A bad supply of springs put MGR under the spotlight for a while, but that particular event doesn't mean that spring fractures are a thing of the past. When introduced, the protector plates were less than a fiver a set. But even at the current £15-£20 a pair most owners see them as a worthwhile addition to safety. It's up to you of course.

TC

[Christopher Price]

If you run a ZT on factory spec Continentals (over £150 a corner) and they save your tyre, I would say that they represent good value, However, if you're running a 75 on 15" chinese death rings, I would say, have a word with yourself, as they are the only thing that keeps the car on the road.

[T16]

See this is the perfect case for a USED TYRE!! (see used tyre thread) *shock* *gasp*

If you have matching expensive tyres, and something bad happens, you can get an EXACT match to the depth should you so desire, thus putting your car back to the status quo.

If I had 4 half used Contis, and one got shredded by a spring, Id never replace just the one with a brand new one, so the other three wear out, and the remaining one is still 50%. )))

[Dragrad]

Originally Posted by T16

See this is the perfect case for a USED TYRE!! (see used tyre thread) *shock* *gasp*

Link please ?

[T16]

Originally Posted by Dragrad

Link please ?

http://www.the75andztclub.co.uk/foru...d.php?t=260528