Old tyres

PostPost by: paddy » Wed Jan 07, 2009 3:22 pm

The handling problems were obviously down to not having van tyres all round. You should know it's wrong to mix and match :)

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PostPost by: john.p.clegg » Wed Jan 07, 2009 5:06 pm

"In the UK, you need tyres that have a speed rating to match the car for the MOT so you will need tyres rated to 120mph. "

Surely that's illegal in the U.K. where the speed limit is 70mph?

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PostPost by: Frank Howard » Wed Jan 07, 2009 5:17 pm

OK. I'm going to throw this out there and I know I'm going to get blasted, but here goes. Michelin invented the radial tire in 1948. They have more experience making radials than any other manufacturer. I've been using them since they came on my first car, a six year old 1964 TR-4. The guy I bought it from lived in a rough part of St. Louis. As a result there were several cuts in the sidewalls from them being slashed. I kept the tires for the entire 20 month period I owned the car. Never had a problem with the tires (although I had plenty of problems with the rest of the car).

I purchased my Elan in 1987. The PO had installed 155-13 Michelin XZXs. I don't know how old they were at the time but (and here's the part that everyone is going to jump on me about) they are still on the car, so that makes them at least 22 years old, probably older. Now I'm not going to argue that they are as safe as they were when they were new or that they have the same grip they had when they were new because they are not as safe and they do not have the same grip. I'm just saying that the safety factor is a matter of degree. Every day you tires get older, they become less safe. But when I hear people saying that 6 year old tires are unsafe, I just don't see the danger. This summer, I took the Elan on a 600 mile trip to Winnipeg. The tires (as well as the rest of the car) performed flawlessly. And I haven't babied the tires either. I take the car autocrossing at least a couple of times a year.

mikealdren wrote:Tyre manufacturers usually recommend not fitting tyres over 6 years old or using those over 10.

Of course they do. They're in the business of selling tires.
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PostPost by: Elanintheforest » Wed Jan 07, 2009 6:42 pm

The tyre age thing has been the subject of a few forums recently, due to failures in tyres that look new, with very few miles on them, but are greater than 10 years old. Sidewall blowouts seem to be the common result of using them.

Here's a couple of extracts:

Vredestein say:

''Tyres older than 10 years must in all cases be replaced, even if they still look good from the outside''

Continental say:

''Continental is unaware of any technical data that supports a specific tyre age for removal from service. However, as with other members of the tyre and automotive industries, Continental recommends that all tyres (including spare tyres) that were manufactured more than ten (10) years previous be replaced with new tyres, even when tyres appear to be usable from their external appearance and if the tread depth may have not reached the minimum wear out depth.''

Michelin say:

''It is impossible to predict when tyres should be replaced based on their calendar age alone. However, the older a tyre the greater the chance that it will need to be replaced due to the service-related evolution or other conditions found upon inspection or detected during use. While most tyres will need replacement before they achieve 10 years, it is recommended that any tyres in service 10 years or more from the date of manufacture, including spare tyres, be replaced with new tyres as a simple precaution even if such tyres appear serviceable and even if they have not reached the legal wear limit.''

Automobile Association say:

''Age is a separate issue to wear ? tyres do degrade naturally through exposure to heat, sunlight(Ultraviolet/UV) light and rain. Degradation depends on the amount of exposure and the severity of the weather. This is a more common problem on caravans, trailers and vehicles only used occasionally. In most cases tyres will wear out before they degrade to such an extent they're unserviceable. Look for signs of UV cracking on tyres four or five years old on cars parked outside. Tyres should be replaced irrespective of age if cracking becomes severe ? any tyre specialist will be able to advise.''

Safety Research say:

'Ford?s addition of a 6-year age limit to its owner?s manuals in 2005 gave an additional jolt to the Rubber Manufacturers Association (RMA), which continues to claim that there is no valid criteria for determining tire service life. In a recent presentation at a tire industry meeting, Ford research scientist Dr. John Baldwin claimed that the 6-year age limit was defend able and data driven, whereas Bridgestone-Firestone, Michelin, and Continental?s 10-yearposition were not supported by any data. According to Sean Kane, President of Safety Research &Strategies, ?the recent spate of tire aging recommendations are a good start, but what is really needed is for manufacturers to label their tires with age expirations based on the specific construction of their product lines much the same way they provide tread wear guidelines of30,000 or 40,000 miles for example.''

Michelin warrant tyres for 6 years from date of sale (not manufacture) regardless of mileage. Also provided tyres have been stored in a dark, cool place and are checked regularly for cracking and de-lamination they should be serviceable.

And finally, how to check the age of a tyre:

"The chronological age of any tyre can be found on the tyre sidewall by examining the characters following the symbol "DOT".

For tyres manufactured after the year 1999, the last four numbers identify the date of manufacture of the tyre to the nearest week. The first two of these four numbers identify the week of manufacture (which range from "01" to "52"). The last two numbers identify the year of manufacture (e.g., a tyre with the information "DOT XXXXXX2703? was manufactured in the 27th week of 2003).

For tyres manufactured prior to the year 2000, three numbers instead of four indicate the date of manufacture e.g 478 = 47th week of 1998."

I don't know about you guys, but brakes and tyres are pretty high in my priority list of things to get right!

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PostPost by: Frank Howard » Wed Jan 07, 2009 7:27 pm

Mark,

Thanks for that great informative post. It appears that the number of years a tire is considered safe varies from manufacturer to manufacturer. I was watching the "Today" show a few months ago and they had a guy on there from the tire industry saying that all tires should be replaced every 3 years. According to him, all of you out there driving on 4 year old tires are taking quite a chance. :wink:

I once attended a tech session at a LOG put on by a lug nut manufacturer. He said that once you have torqued your lug nuts three or four times, their effective life is over and they could fail unexpectedly. Naturally he recommended replacing them with new ones. :shock:
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PostPost by: denicholls2 » Wed Jan 07, 2009 7:33 pm

Don't rate a tire size's performance by test-driving one brand's nine-year-old tire. In all probability, the age of these tires alone is the reason why they don't stick. Tires get considerably harder with age, and these are now quite elderly.

I'll opine that given any quality tire in the original size that you find available, you should be quite satisfied with the performance unless you're going racing. My Europa, for example, wears Kumho 165 R 13's at less than $30 U.S. apiece and it takes some pretty insane driving to unsettle them.
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PostPost by: gerrym » Wed Jan 07, 2009 7:57 pm

Roy, if you are looking for a grippy in the wet tyre for a Plus 2, don't intend to do high speeds on Autobahns etc, and are happy with a life measured in thousands of miles, then consider a motorsport tyre.
For example camskill.co.uk list Yokohama A021/Rs in 185/70R13 (sticky tyre) at ?76 each including VAT. I pay much more than this for the wife's runabout footprints so it puts it in perspective. This tyre gets close to the original rolling diameter of the 165Radial tyres originally fitted to the Plus 2. These tyres are E-Marked and Road Legal (not withstanding comments on speed rating).

Regards

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PostPost by: Roy Gillett » Thu Jan 08, 2009 9:51 am

Hi Gerry,

Thanks for the suggestion. I am not sure that there is room for 185's on the front . My 175/70's only clear the bottom front edge of the wheelarch when on a little lock with a little suspension conpression by a whisker. My calculations suggest 185's would have an additional half inch radius which would certainly bring tyre and body into contact on my car. Do they do a 175 I wonder?

I must say what has been said before about how excellent this forum is. You always get such helpful and well-informed feedback. I have learned a lot from this thread. Thanks everyone

Roy

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PostPost by: steveww » Thu Jan 08, 2009 9:54 am

I use Michelin XAS FF tyres on my S4 in original size 155x13, they are also available in the +2 size. Available in the UK from Longstone Tyres.

They are very soft and have a stiff side wall. They grip very well while remaining progressive when they do break away. The delicate feel of the Elan is maintained which is lost when fitting wide rubber. However they are not inexpensive at around ?100 a corner - ouch. The ones on my car have done approximately 5000 miles and still have plenty of life left in them but I would not expect to get much more than 10000 miles in total. This includes a few track days each year. I also swap front to rear each year.
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PostPost by: mikealdren » Thu Jan 08, 2009 4:05 pm

After Mark's comprehensive post put me to shame, I decided to check on the government website for MOTs and the MOT testers' manual says:

Note: A Class III or IV vehicle tyre which appears to be of inadequate size, ply or speed rating for the vehicle or its use is not a reason for rejection. However, the vehicle presenter should be informed.

It seems we can get away with any speed rated tyres. Good news indeed.

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PostPost by: msd1107 » Sat Jan 10, 2009 10:48 am

It is not a good idea to use small or low speed rated tires to save a small amount of money.

A H or T rated tire is generally designed for a low performance sedan, and has degraded cornering and braking performance compared with S or V rated tires. And these tires generally come with very high tread wear rating, ensuring the tire ages to hardness well before the tread wears.

In this regard, replacing tires at 3-5 year intervals falls into the same good periodic mantenance practices as replacing coolant fluid, brake fluid, etc at regular intervals.

As tires age, they lose ultimate performance levels, but at such a low rate that it is undetectable on a day to day basis. It only becomes apparent in an emergency situation when you need the performance the most, and suffer the most with the degraded performance.

In this regard, 400 GBP every 3 years or so is cheap insurance, and maintains the performance level of your Lotus at its proper high level. And all but the most exceptional daily driver will get more than 2 years service from their XAS tires.

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PostPost by: Frank Howard » Sat Jan 10, 2009 4:52 pm

msd1107 wrote:In this regard, 400 GBP every 3 years or so is cheap insurance, and maintains the performance level of your Lotus at its proper high level. And all but the most exceptional daily driver will get more than 2 years service from their XAS tires.

David,

You must know something the rest of us don't know. Please let us know where we can get a set of XAS tires for that kind of money.
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PostPost by: msd1107 » Sun Jan 11, 2009 7:55 am

steveww posted about XAS tires being available for 100 gbp from Longstone Tyres.

I'm at CES in Las Vegas, so don't have access to further data.

I seem to remember XAS being priced in the $200 range awhile ago. As usual, our British friends have better availability than the US folks.

But no matter, we drive a high performance historic vehicle, and replacing tires as a maintenance item is part of the bargain for which we implicitly signed up as part of the Lotus heritage and culture.

Of course, everybody treats their car as they see fit.

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PostPost by: CBUEB1771 » Sun Jan 11, 2009 12:40 pm

msd1107 wrote:I seem to remember XAS being priced in the $200 range awhile ago. As usual, our British friends have better availability than the US folks.


In the US, Coker Tire
http://www.cokertire.com/
is currently listing Michelin XAS FF in 155HR-13 and 165HR-13 at $223 and $237, respectively. Not too long ago I bought a set in 155HR-15 from Coker for my Elite.
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PostPost by: garyeanderson » Sun Jan 11, 2009 2:04 pm

Frank Howard wrote:OK. I'm going to throw this out there and I know I'm going to get blasted, but here goes. Michelin invented the radial tire in 1948. They have more experience making radials than any other manufacturer. I've been using them since they came on my first car, a six year old 1964 TR-4. The guy I bought it from lived in a rough part of St. Louis. As a result there were several cuts in the sidewalls from them being slashed. I kept the tires for the entire 20 month period I owned the car. Never had a problem with the tires (although I had plenty of problems with the rest of the car).

I purchased my Elan in 1987. The PO had installed 155-13 Michelin XZXs. I don't know how old they were at the time but (and here's the part that everyone is going to jump on me about) they are still on the car, so that makes them at least 22 years old, probably older. Now I'm not going to argue that they are as safe as they were when they were new or that they have the same grip they had when they were new because they are not as safe and they do not have the same grip. I'm just saying that the safety factor is a matter of degree. Every day you tires get older, they become less safe. But when I hear people saying that 6 year old tires are unsafe, I just don't see the danger. This summer, I took the Elan on a 600 mile trip to Winnipeg. The tires (as well as the rest of the car) performed flawlessly. And I haven't babied the tires either. I take the car autocrossing at least a couple of times a year.

mikealdren wrote:Tyre manufacturers usually recommend not fitting tyres over 6 years old or using those over 10.

Of course they do. They're in the business of selling tires.


I went to a Lotus Elite owners get together in L.A. in March of 2006. An owner that had bought his Elite new in 1960 showed up with the Elite and all of its original tires, he had driven it 40 or so miles in each direction. I don't think he had a lot of fun heading home but I heard the he did make it home that afternoon but the next year he blew everyone away when he showed up with 4 new sneakers on the Elite. What a spend thrift, he could have rotated the fronts to the back and got another 10 years use... :)

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