Vintage tyres and car shimmy

[bob hughes]

With all this daily travelling ( 120 miles a day, my tax disc still has not turned up) it has put pressure on the inner tubes and one collapsed on me over the week end, least ways an old repair gave out. Had to take it to the local tyre man twice before we sorted it out with a new tube. Whilst I was there he pointed out that three of my tyres ( the spare and the two rears ) were older than most of his staff, it turns out that they are Firestones and are of a section not made in England and were made in the second week of January 1987, according to the code. The car was imported back from America and swung over to RH drive at some point and has retained all the tyres from that era until recently, when I renewed two due to damage from the seat belt fixings in the rear arches.

This could be the cause of my shimmy at around 60 MPH due to distortion with age, has anyone any experience of checking tyres for ovality etc, I have a dial guage and magnetic base, so could set up a check but do not know what a resonable tolerance would be before things would start to affect the drive quality.

Bob

 

[GregW]

Doesn't really matter if they are oval, they are too old to be safe.

 

[anthony7777]

bob hughes, to quote terry thomas in some movie "my god man are you mad" get rid of those old tires before something more catastrophic happens, youll find a vast improvement in ride, handling and safety, /bcforum/images/%%GRAEMLIN_URL%%/savewave.gif

 

[Dave Russell]

Hi Bob,
There is little doubt that the tire aging process starts as soon as they are manufactured & is "the start of a clock". Tread hardening, & tread SEPARATION are the most common problems associated with age hardening. ---

This hardening is actually a slower extension of the original vulcanizing process which is used to harden the soft green rubber to it's intended hardness when it is manufactured. The hardening never stops.

How long it takes to harden a tire to unsatisfactory traction or safety levels, depends on temperature, amount of ozone exposure, & amount of ultraviolet exposure, both during storage & during use. Tires age even while on the shelf.

On the tread separation/safety issue, several European car manufacturers recommend a tire age limit of around six years, & Ford & Chrysler have recently adopted a maximum tire age recommendation of around six years.

I believe that this is a real concern & not just an excuse to sell new tires. An old tire which still has 100% tread is still as likely to separate as is an old tire with no tread.
D

 

[AJAX50]

My ex-US BJ8 had good tread,old tyres on it. I ran it like this for several years, it was like driving on ball bearings. I thought this was normal for a Big Healey. I found out about tyre ageing and replaced the 10 year old Goodyears. The diffence was huge, the car now grips, handles and stops. Replace 'em.

 

[bob hughes]

Thanks guys

Looks as if I had better invest in some replacements PDQ.
On my last run in to work tomorrow before the tax disc arrives for the company motor, I will have covered around 960 miles and I think that the exhaust will require some TLC but otherwise all is holding together fine.

Bob

 

[healeynut]

I just put new vredesteins on the BJ8, replaced my 15 year old Rikens (the tread has seperated on one of them). Best money I spent in 15 years for my BJ8. Don't wait, new tires!!!

If you're in the UK Longstone Tires is very good. Be sure to replace all of your tubes with michelin reinforced tubes while you're at it.

 

[anthony7777]

dave, less he change them tires his aging process will cease. /bcforum/images/%%GRAEMLIN_URL%%/grin.gif