Spare Tyre

[GlennS]

I've been poking around in the back of the S2 and chanced to look at the spare tyre. It occurs to me that it has probably been sitting there rotting away for 20 years and is unlikely to hold pressure. Even if it does, I don't really feel inclined to trust my life to it.

Are replacement new tyres economically available or is it a case of giving up and carrying a can of tyre-weld around?

 

[sawood12]

You could get a partly worn for a cheap price/. I was looking at getting a Boxster spacesaver wheel for mine - smaller and lighter. They seem to be going on Ebay for about £50 ish. I never did take the plunge though.

I would not advise relying on a can of tyre weld. My recent experience with the Smax which basically has no spare but a bottle of sealant proved to be not effective due to the nature of the damage to the tyre. My wife was left stranded with the kids in the car and i had to come out of work to sort things out. I don't want to be in a situation of having to wait around for the AA/RAC to tow me round to the nearest rip-off merchant for a new tyre. I will be looking to get a space saver for the Smax at some point.

Modern radial tyres rarely deflate as a result of picking up nails these days. I've found nails in tyres that have maintained pressure and I could have been driving around for months with. So any damage to a tyre that causes it to deflate is more likely than not to be severe enough such that tyreweld wont work. Also tyreweld effectively writes off the tyre - even if my Smax tyre was repairable the fact I would have used the sealant meant i'd have been looking at a new tyre anyway.


Better to have a spare, swap the wheel by the roadside and get yourself home or to a tyre supplier of your choice.

 

[GlennS]

I couldn't agree more with regard to tyre-weld; horrible stuff but better than being stuck by the side of the road when you need to be somewhere in a hurry!

The Boxster spacesaver is an interesting idea assuming I can get one in approximately the right size. I'll look into that.

Still interested to hear what solution others have come up with.

 

[zcacogp]

Interesting points about both tyre weld and replacement tyres.

However, don't be too down on the spare as it stands at the moment. I had to use the spare on my S2 ('89 model, so at least 20 years old) a couple of years back and it worked fine. If you are worried about it, try inflating it and seeing how much pressure it holds - you may be surprised.

(Inflating it for a laugh is also recommended; it's a very weird thing to watch, seemingly defying physics. When I took my car - with the spacesaver - to the tyre repair place to have the puncture repaired, I removed the spacesaver tyre and deflated it - which is just as weird to watch. And half-way through I realised there were three tyre fitters standing around me, watching, as they had never seen anything like it before in their lives!)


Oli.

 

[GlennS]

I may very well inflate the spare as a comedy exercise and it will be interesting to see if it does hold any pressure.

The ability to hold pressure, however, isn't really much of an indication of a tyres safety. A static pressure test is nowhere near the stresses and strains from temperature and load that a tyre has to accommodate when supporting a quarter of the car's weight.

The AA express concerns when a tyre is more than about 5 years old. According to a study done by Kane in 2003, "old tyres - more than five or six years old - become increasingly susceptible to to separation or blow-out because tyre components dry with age and can separate causing the tyre material to disintegrate". A 1997 Mercedes report states that "Tyres undergo an ageing process even when they are not in use. The rubber parts become less elastic, the steel webbing inside the tyre corrodes and the rubber mixture of which the tread is formed hardens". Such problems are often not detectable from a visual inspection.

The only "sure" way to know would be to put the tyre on the car and drive it. You may get away with it and you may not. It would depend on the stresses and strains that a particular tyre has suffered during its lifetime and the climatic conditions it has experienced; a tyre which spent its life in the balmy south may be in a different state to one that spent most of its time in the North of Scotland, for example. One tyre could be near-perfect after 20 years and one could be a death trap.

Of course, if you put the tyre on the car and find out that it is defective after 20 years in the boot, then you might discover that in very unpleasant manner involving damage to you, the car and possibly other people.

That's why I'm posing the question about more modern alternatives.

 

[Alexw]

I had to use my spare on my S2 earlier this year also ('89 also) and it was fine. I think that 5 year rule only stands for tyres on a car, that see sunlight, frost, road crap etc. The spare thats safely tucked out of sunlight should be fine.

 

[GlennS]

I am pleased that it worked OK for you, but no... it also applies to tyres unused and in storage. In fact, apart from the comment by the AA, the other two sources I referenced were specifically about tyres in storage, unused.

A simple google search for "age related tyre degradation" will pull up plenty of material on the subject. Here's a link to only one of many articles.

http://www.hfes.org/Web/HFESNews/tireaging.pdf

 

[sawood12]

ORIGINAL: sc0tty



The comment above regarding tyre weld writing off the tyre is a popular misconception, caused by tyre fitters being too lazy or unprepared to remove the gel from inside the tyre. If you contact the tyre weld manufacturer (holts?) they will provide a letter that clearly states the tyre CAN be repaired. You then have 2 choices, get the local tyre place to remove the tyre for you, then take it home and clean the gel out of the tyre, then take it back to a tyre place for the repair, or take the manufacturers letter to the tyre place and battle it out with them ! (I prefer the first option)

I have two cans of the tyre weld in the back of my 944. For no other reason than to save weight. BUT I only do about 3000 to 4000 miles per year as the S2 is my second car and a weekend toy.

This advice actually came from the cars handbook and not the tyre fitter or some grease monkey. Anyway, even if it is not true then it is a bit pointless if no-one is prepared to do anything with a tyre that has had this stuff used on it. The stuff smelt pretty toxic so I wouldn't be surprised if it has some chemical in it that over time attacks the rubber.

Rubber is attacked by oxygen as well as UV light, so even if you keep a tyre out of sunlight it will still degrade over time. As a 'get you home spare' i'm sure that a 5yr old or even older tyre will be perfectly fine as long as it can hold pressure.

A boxster spare is a 16" rim so should fit fine on a 944.

 

[chrisg]

glenn

as per my PM, i have an excellent condition S2 alloy space saver for sale. PM me if you're interested ?

chris

 

[944 man]

I used a 22yr old non-collapsible type spare a few years ago: It faired well enough on a five hundred mile (not too slow) drive back through France and England. Had it not occured on the final day, then itd have been all over the Alps too.....

 

[Northern924]

I've had given serious though to putting my '44 back on 15" teledials just so that i could have a full sized spare, but that though didn't last long LOL

Good to see you over here as well Glenn []