Why would tyre pressures vary? The only difference between the plys would be the max pressure rating.
Obviously if you take a 8 ply off you should put an 8 ply back on with the same load rating.
Quote: Originally posted by wizard9956 on 30/3/2009
I posted the pictures to show people what to look for when they check their tyres , who makes them isn't the point i'm trying to get across.
Why does it matter if the tyres are cheap ones ? does this mean that if you have expensive tyres you don't need to check them .
atb
Wizard
Of course it matters if tyres are cheap ones, budget brands tend to crack up quicker than premium brands, which is the point I was trying to get across.
Obviously people need to check their tyres but it helps if they buy good quailty ones in the first place.
------------- Sell my camper? I'd rather eat school semolina!
Quote: Originally posted by wizard9956 on 30/3/2009
I posted the pictures to show people what to look for when they check their tyres , who makes them isn't the point i'm trying to get across.
Why does it matter if the tyres are cheap ones ? does this mean that if you have expensive tyres you don't need to check them .
atb
Wizard
Of course it matters if tyres are cheap ones, budget brands tend to crack up quicker than premium brands, which is the point I was trying to get across.
Obviously people need to check their tyres but it helps if they buy good quailty ones in the first place.
As a brand spanking newbie picking up our first caravan last year, I genuinely wouldn't have had a clue whether the tyres on our new acquisition were budget or really expensive. It was only when I read a post at the time (and this is the frightening bit) it even occured to me to change them never mind check them ("but surely they'll last 15 times longer than a car tyre because they're not used as much??".... Told you it was frightening.....). I remember the description of torn up wheel arches were enough to make me realise that I needed to read far more on this caravanning lark to keep myself, my family and other folks on the road safe. Wizard is making a completely valid point here (beautifully illustrated and double underlined with photographs) which I have no doubt newbies will be using as food for thought and experienced vanners will be using as a kick up the to change their old tyres.
Quote: Originally posted by CandP on 30/3/2009
Why would tyre pressures vary? The only difference between the plys would be the max pressure rating. Obviously if you take a 8 ply off you should put an 8 ply back on with the same load rating.
or have I just mis-read what you have put?
Any given weight requires a fixed volume of air to support it, in the case of a tyre, the difference in pressure is directly related to the space or volume within that tyre, the smaller the space the greater the pressure require to get it all in.
A stronger tyre construction allows more volume of air to be forced into the same space without it bursting, the stronger construction though must take space internally as the standard requires the outside dimensions of any particular sized tyre, (with the exception of 'reinforced' tyres), to remain the same
As an example a standard 165/80x13 4ply (car) tyre carries a maximum 487kg at it's max pressure of 35psi, a 6 ply of exactly the same external dimensions carries the same weight at 40psi and an 8ply at 44psi,
The reason is the internal volume of the tyre has reduced to give room for the stronger, (thicker), construction, the volume of air remains the same so requires a little more force to shove it in.
I also agree Wiz was quite right to remind us all another winter has gone by and the vans tyres another 6 month older probably stood idle suffering the elements.
I would add the tyres should be inspected off the van, not only can the inside face be better inspected but both sides seen from above will show up bulges far more clearly.
I might ask though what early year 2000 tyres are still doing on your van Wiz?
Quote: Originally posted by arc systems on 30/3/2009
Quote: Originally posted by CandP on 30/3/2009Why would tyre pressures vary? The only difference between the plys would be the max pressure rating.
Obviously if you take a 8 ply off you should put an 8 ply back on with the same load rating.
or have I just mis-read what you have put?
Any given weight requires a fixed volume of air to support it, in the case of a tyre, the difference in pressure is directly related to the space or volume within that tyre, the smaller the space the greater the pressure require to get it all in.
A stronger tyre construction allows more volume of air to be forced into the same space without it bursting, the stronger construction though must take space internally as the standard requires the outside dimensions of any particular sized tyre, (with the exception of 'reinforced' tyres), to remain the same
As an example a standard 165/80x13 4ply (car) tyre carries a maximum 487kg at it's max pressure of 35psi, a 6 ply of exactly the same external dimensions carries the same weight at 40psi and an 8ply at 44psi,
The reason is the internal volume of the tyre has reduced to give room for the stronger, (thicker), construction, the volume of air remains the same so requires a little more force to shove it in.
Quote: Originally posted by CandP on 30/3/2009
Branded tyres are better as there is more rubber in the rubber. i.e Cheaper tyres have more fillers in them that will break down (Cost Reduction), and give them less strength. Also branded tyres have a greater wall thickness, given greater stability and less chance of a blowout. granted all tyres have to pass the safety regs, but why put a tyre on that just pass's? Put a tyre on that can be trusted.
Plus they are on contact with the road...Would you feel confident knowing that a plane you were in had a set of cheap remoulds on it? or would you feel safer knowing it had a nice set of fresh Dunlops on it? I know what I would prefer.
I was at a tyre manufacturer about two weeks ago due a problem with the manufacturing process on what they call the calender. I was asking the same questions to why there is a vast difference in price.
You might be suprised to know that they REMOULD plane tyres.
I did check the tyres on my new (to me) van and thought they were ok, I didn't take the wheels off pre-purchase.
Luckily for me, when I had the service, it was included and once my Engineer took them off, he advised I needed one new one as it had just started to crack on the inside.
I could barely see the crack, but straight off to the tyre centre and got it changed. I've no idea if it's a buget tyre (so it probably is lol) but if I need to change it/them again next year, so be it.
It's a nice feeling knowing I've done everything I can to be safe.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.
Topic: Got tyres on your caravan , then see here
to change their old tyres.
