Tyres

[Guest Brian Kirby]

Have any of you technically learned types spotted a letter in the January Caravan Club mag (p17) from a Mr R Grogan on the above subject? He appears to slay two sacred cows, both promoted by the Caravan Club (among others), at a single stroke! SC1: he says the tyre industry has recently published guidance to users and retailers saying that tyres over six years old should not be fitted, and tyres over ten years old should not be used. I had always understood that tyres over six years should not be used, leave alone fitted!! The clear implication being that retailers can fit tyres that, hitherto, I would have rejected as old stock. SC2: he says that radial ply tyres do not deteriorate due to being left standing for extended periods. His comment appears to be aimed at caravanners, as he advises there is, in reality, no need to use axle stands during a winter lay up. However, a tyre is a tyre, so presumably (provided inflation pressures are maintained), motorhomes do not need to be moved just to "exercise" their tyres. I accept that there are other, equally good reasons for moving 'vans, but I had always understood the main reason to be prevention of "flats" on tyres that stand immobile for extended periods. He says this particular advice truly related only to cross ply tyres, and especially to nylon corded cross plys. He also says the steel belts in radials have a tendency to de-bond from the carcass as a consequence of age, i.e. not due to use (but does not quote a timescale), claiming also that this tendency is exaggerated on low mileage tyres. He signs himself a tyre consultant from Acocks Green (Birmingham), therefore claiming a degree of expertise. Martin Spencer, the Cravan Club technical officer, adds a footnote saying he agrees, and points to p593 of the Club Sites Guide, wherein it states "tyres have a life expectancy of typically five years, and should never be used for more than seven years from their date of manufacture". Eh??! Agrees!! With what, exactly? Please discuss. Happy New Year to you all, Brian

[Guest Clive]

My Michelins are comming up to 9 years old and still bags of tread and no sidewall cracking. The rears certainly are always at maximum pressure (65 PSI) and the front suitably inflated. I don,t go along with the theory of deflating until the ride is nice and soft as this puts the handling at risk, increases tyre running temperatures and reduces tyre life. What is worth doing is NOT parking with the tyres in full sun. Inflate to manufacturers recomendations and will tall vehicles like motorhomes err on the high side. The only blow out I have ever had was on a earlier DIY coachbuilt motorhome based on a 29 seater coach. Twin rears and I ran them on remoulds. One of a pair departed quickly taking the wheel arch lining with it. It was only the BANG behind and the puff of dust seen in the nearside mirror that caused me to stop and investigate - and pick up the debris. So two morals I guess, 1) Don,t run remoulds unless its on twin tyres. 2) You never know how old the base tyre is with a remould. Go in peace! C.

[Guest MelE]

Tyres, like most manufactured goods, have improved hugely in the last 20 to 30 years. When I compare my first car (1953 Ford Prefect, 3 gears, side valve engine, 'orrible suspension, etc), my first shiny new car (1970 Ford Mk2 Cortina with an A4 page full of warranty correction defects after less than 2 weeks) with a new car today (eg my wife's now-year-old Skoda Fabia VRS with nothing wrong at all after a year), it's obvious that tyres too have improved. BUT, THE OTHER REASON for moving your van regularly is to exerceise the engine. Even modern diesels - especially turbo models - do not like to be left standing for long periods, so a run round the block really will improve both their life and reliability. Yes, I know life isn't really an issue with motorhomes, but reliability is.

[Guest David Powell]

I have just re-read those letters in the Caravan Club magazine, and like you say, Brian, "Agree with what"??? they are all contradicting each other, so we can never learn anything from that lot. An old caravanning pal of mine who owns our local tyre company, works on the principal that the longer a tyre stands around doing nothing in day light the more the rubber will deteriorate, loose some of it's flexability, and it's traction qualities become poor, and the faster it will wear out. He also impresses on his customers the importance of the condition of the rubber part of the valve, which also becomes perished over time. I reckon it is better to retire our tyres while they are still active rather than have them 'give up the ghost' and die on the job taking us with them. I think the old 5 year age limit is a good safe rule of thumb.

[Guest Brian Kirby]

Thank you. Problem is, who does one believe, the Club or the consultant? Clive's are OK according to the latter, but should have been ditched two years ago according to the former! Incidentally, I hope no one deflates tyres until the ride is nice and soft, Clive. I run mine at the pressures recommended by Michelin, who make tyres (my tyres), and not those recommended by Burstner, of Fiat, who do not - but who recommend pressures designed to safeguard overloaded vehicles! If the tyres are over inflated the risks are also poor handling, increased braking distances and accellerated wear. Correct inflation is governed by the load on the axle and the exact specification of the tyre. 65psi is as likely to be wrong as 45psi, if you don't know your fully laden axle loads and the tyre manufacturer's recommended pressures for the precise size and type of tyre fitted. To David I'd only say, with the greatest of respect to his old caravanning pal (as they say!), but how does he know? Where is his evidence? Based on experience, undoubtedly, possibly on years of that valuable commodity, and equally possibly correct. It is also a "safe" conclusion, in the same sense that changing they after three years would be even safer. However, being a jaundiced cynic I still have a little nagging voice saying to me who gains? In whose interest is to get us to change our tyres sooner rather than later? If they remain perfectly safe and legal for ten years, it seems not ours. Remember, this is not about tread depth, just age. Then there's the little problem of disposal. If the tyres are functionally safe for 10 years, and David is changing his after five, he could halve the pile of his tyres lying around to be re-cycled at a stroke if he kept them for the longer period. I'm not advocating he should, mind, but it makes you think, doesn't it? Keep them coming! Regards Brian

[Guest Malcolm M]

I had to change all 4 tyres on my last van although they were only about 4-5 years old. Reason? - the previous owner had hardly used the vehicle and had left it standing in the sun. As a result the walls were ruined. Answer? Make up some marine ply covers and attach them to the tyres with bungy elastics in between trips. No more cracked side-walls.

[Guest David Powell]

Well Well Malcolm M you are posh, Marine ply!!I use some old three quarter length padded car coats with the sleeves pulled inside out, they fit over the wheels lovelly and snug. Don't even use bungy, they even stay on in a storm. No Brian, my old friend doesn't produce any proof, just 50 years in the tyre trade. He knows things and we just listen and take advantage of what he has learned over the years by his 'hands on' experience. After all! what is an expert???????Lets hear some more expert advice.

[Guest Ralph]

The question posed was what is an expert? I have always been led to believe that 'X' is the unknown quantity and a 'spert' is a drip under pressure!! :,)

[Guest David Powell]

Yes Ralph...I have always heared a similar one:- An EX is a HAS BEEN, and as you say a spert is A DRIP UNDER PRESSURE.

[Guest bill]

As a highly skilled and qualified expert of some 50 years in my field that involved production lines of the motor trade, I was constantly referred to as the expert. My personal view is very open in that as an expert it allowed me to tell outright 'porky pies' with a smile, for I could not be challenged. I would constantly explain my theory when being labelled so. I therefore always cast doubt upon others who advertise themselves as 'experts'. bill

[Guest Brian Kirby]

Now, now, boys and girls. Please!! This is not about experts, or their provenance, but about how long it is safe and legal to keep your tyres. This is about motorhoming costs. Received wisdom, hitherto, has been that tyres only last about six to seven years, irrespective of wear. Now up pops a man, who says he is a tyre consultant (so presumably independent of the tyre industry - for that is what a consultant properly is), who says they actually last for ten years. Now, it is probably the case that most of our tyres will need replacement due to wear before they are ten years old, but seemingly not all. Those among us who have ditched our partially worn tyres merely because they were seven years old could, safely and legally, according to yer man, have carried on with them for another three years. That three years represents a considerable difference in tyre costs over the life of a motorhome. Don't forget this applies equally to the spare, so it's all five (or more) tyres we're talking about here. Just ask yourselves who gains. What might the consultant gain if we keep our tyres for ten years? What might the industry gain if we change them after seven years? First answer, apparently, nothing. Second answer, a whole additional set of five (or more) new tyres during the average life of the motorhome, or over £500 at todays prices. So, good for business at least! Then, if you change tyres after five years, to be on the safe side, that's two extra sets of tyres at £500 or so per set (Don't worry too much about the arithmetic, or whether you can get them cheaper elsewhere, it's the principle that we're after here). On the second point, what yer man actually said was that radials don't develop flats when left standing, whereas cross plies do (did). Therefore, he says, you don't need to move your radially shod 'van to stop flats developing. No more, no less! Sidewall deterioration due to sunlight (U.V.) is quite another matter, on which he did not comment. What interested me was the manner in which the received wisdon was upended, and one of the proponents of the received wisdom just said "I agree", and then referred us straight back to the received wisdom without pausing for breath. Have a read - and see what you think. Happy New Year Brian