TYRES AGAIN !

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Oct 17, 2010
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I can only speak for Swift but all thire singe axle vans have "C" rated tyres, largest being 195/70 R15C Although as has been said not on Twin axles, (which I didn't check). From at least 2012 till this year.

Looking at these specifications, I'm afraid it was me that first mentioned "C" rated tyres :oops:

Like for Like is the easiest way to go.
 
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Nov 11, 2009
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"C" rated is an outdated rating - Load Rating has been the rating method for many years, it covers most types of tyres including cars and commercial vehicles - there's no such thing as "car tyres".

C isn’t a load rating it’s to denote it’s a light truck tyre with construction more suited to commercial usage such as delivery drivers, twin rear wheeled load bed trucks etc and of course some caravans, mainly single axle units. . It’s still very much in use just look at the major tyre makers own websites.

Heres my caravan makers label for my tyres. It shows a “C” and the respective load rating of 99. So it’s quite clear what tyres are required come replacement time.

C041DC5C-3DAE-4027-9017-E60C289F54AB.jpeg
 
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Oct 17, 2010
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C isn’t a load rating it’s to denote it’s a light truck tyre with construction more suited to commercial usage such as delivery drivers, twin rear wheeled load bed trucks etc and of course some caravans, mainly single axle units. . It’s still very much in use just look at the major tyre makers own websites.

Heres my caravan makers label for my tyres. It shows a “C” and the respective load rating of 99. So it’s quite clear what tyres are required come replacement time.

View attachment 834

Brought three for mine two years ago, hope to be able to replace in three or four years time. My Max is 1350kg
 
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Nov 6, 2005
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C isn’t a load rating it’s to denote it’s a light truck tyre with construction more suited to commercial usage such as delivery drivers, twin rear wheeled load bed trucks etc and of course some caravans, mainly single axle units. . It’s still very much in use just look at the major tyre makers own websites.

Heres my caravan makers label for my tyres. It shows a “C” and the respective load rating of 99. So it’s quite clear what tyres are required come replacement time.

View attachment 834
Try finding an official definition for "C" rating - there isn't one, it's just a marketing description like "M+S"
 
Nov 11, 2009
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Try finding an official definition for "C" rating - there isn't one, it's just a marketing description like "M+S"

Or Three Peaks and Snowflake symbols too They give an indication of performance but you get varying degrees against a criteria that’s not defined either. I’m afraid that’s a fact of life for many things.
 
May 2, 2020
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If I remember correctly the C stands for commercial which usually means that the tyre is 8 ply and can be used on vans, trucks and trailers
 
Oct 17, 2010
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One things for sure, my tyres fitted to my van are 175R14C Q and I shall replace like for like. If anything should happen and everything goes west, arguing with the insurance company whether the right tyres are fitted or not is a No No.
 
Nov 11, 2009
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If I remember correctly the C stands for commercial which usually means that the tyre is 8 ply and can be used on vans, trucks and trailers

8 ply is a long superseded tyre construction technique but serves to let North American ( conservative) buyers associate later generations of tyres as being suitable for their trucks. It’s still marked on some tyres but when you check the actual number of plies it doesn’t equal 8. The link in post 25 describes.
 
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Jun 16, 2020
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I'm sorry but your posting has conflicting advice.

The caravan Manufacturers would be selling unroadworthy caravans if they fitted tyres with a lower load rating than the caravans axle rating. Consequently their specification for the tyre should be more than adequate for sourcing replacements.

The load rating of tyres is specified as the static load, and as we all know the effects of motion dynamics can significantly create forces that load tyres well beyond their static ratings, so there should be no problem using the OEM specification.

The CMHC implies there is no need to fit tyres with a greater load index, but there is no harm in doing so - all it really does is to give the owner a greater sense security.

Owners should not overload their caravans, so there is no need to research new sizes or types of tyre provided the OEM specification is still available.

You have not explained why that was conflicting advice. It is provided for a number of reasons.

1. CMHC, also say, and I quote.

“However, it is more common that manufacturers specify a tyre which is only just capable of such a load, and owners may wish to increase the safety margin when choosing replacements.“

I provided the link to this earlier.

2. The suitability of tyres extends beyond the ratings, if not why do Avon say not to use their tyres?

3. Although dismissed by others as “confusing”. The twisting action twin axle vans is very real and, something I for one would certainly consider if I was purchasing.

4. As stated in the same link. Fitting a higher rated tyre can be counter productive. Which is contrary to what you said.

“The CMHC implies there is no need to fit tyres with a greater load index, but there is no harm in doing so - all it really does is to give the owner a greater sense security.


John
 
Jun 20, 2005
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Twin axle tyres are clearly specified by the caravan manufacturer. Stick with their advice no problem . Not sure why that one got raised?
Where the load indexing shows 94/92 for caravans only you can use the higher figure.
Forget this phrase car tyres . What matters is you follow the technical specification given by say Swift or Alko. I really don’t understand how all this banter satisfied the OP🤪🤪
 
Nov 11, 2009
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Twin axle tyres are clearly specified by the caravan manufacturer. Stick with their advice no problem . Not sure why that one got raised?
Where the load indexing shows 94/92 for caravans only you can use the higher figure.
Forget this phrase car tyres . What matters is you follow the technical specification given by say Swift or Alko. I really don’t understand how all this banter satisfied the OP🤪🤪
Neither do I as on two very early posts I advised going with the OEM manufacturer specified tyres. Unfortunately some patently incorrect posts relating to “C” rating being speed rating, and inaccurate speed ratings, plies etc all served to complicate what in my mind is a straightforward decision. The OP made his mind up many posts back to buy five of the same specification as he’s got.
Passed a rainy afternoon watching scaffolding progressively cocoon the house though. 😂😂
 
Mar 14, 2005
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You have not explained why that was conflicting advice. It is provided for a number of reasons.

1. CMHC, also say, and I quote.

“However, it is more common that manufacturers specify a tyre which is only just capable of such a load, and owners may wish to increase the safety margin when choosing replacements.“

I provided the link to this earlier.

2. The suitability of tyres extends beyond the ratings, if not why do Avon say not to use their tyres?

3. Although dismissed by others as “confusing”. The twisting action twin axle vans is very real and, something I for one would certainly consider if I was purchasing.

4. As stated in the same link. Fitting a higher rated tyre can be counter productive. Which is contrary to what you said.

“The CMHC implies there is no need to fit tyres with a greater load index, but there is no harm in doing so - all it really does is to give the owner a greater sense security.


John
Your stance seems to be confusing:-

You seem to supporting the suggestion that caravan owners should consider upgrading from OEM tyres (caravan manufacturers specification).

Yet you are also suggesting that upgraded tyres will suffer more on TA's. So how can a TA caravanner choose a suitable tyre?

I have no connection with Cooper/Avon or the CHMC so if you need clarification on their position advice you must speak with them.

I am more than aware of the complexities that twin axles bring across a variety of issues not just tyres, but I equally believe the chassis manufacturers in particular will also have a good understanding of the forces involved, and will have designed and specified components that are satisfactory to cope with those forces for their given loads. They will have advised their customers (e.g. caravan manufacturers) of the minimum specification tyres to use to keep the trailer road legal and safe.

Companies can of course get it wrong sometimes, but for both the chassis manufacture and teh caravan body manufacture to both get it wrong is a diminishing probability.

All the OP needs to do is source tyres of the same specification.
 
Jun 16, 2020
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Your stance seems to be confusing:-



You seem to supporting the suggestion that caravan owners should consider upgrading from OEM tyres (caravan manufacturers specification).

Correct, which is what the CMCH recommend considering, which is one of the quotes I provided. OEM is often underspect. not on necessarily on loaings, but on quality.

Yet you are also suggesting that upgraded tyres will suffer more on TA's. So how can a TA caravanner choose a suitable tyre?

Correct, and this is where it is difficult to obtain definitive supporting evidence, my knowledge is hearsay, and what I have read elsewhere. This is why I was careful to advice getting advice from the manufacturers. If I was purchasing for a twin axle, it is certainly what I would do. I believe, which means it is just my summation. That say upgrading to commercial tyres with much stronger side wall would not cope with the twist like good quality car tyres.

I have no connection with Cooper/Avon or the CHMC so if you need clarification on their position advice you must speak with them.

Someone recently started a thread about Avon. For whatever reason they do not recommend there tyre for use on caravans. I have no wish or need to speak with them. I was merely saying there is more to consider when purchasing tyres than the size and load rating etc.

Re CHMC I provided the link to be inspected to support what I was saying. You don’t need a ‘connection’ with them in order to read it.


I am more than aware of the complexities that twin axles bring across a variety of issues not just tyres, but I equally believe the chassis manufacturers in particular will also have a good understanding of the forces involved, and will have designed and specified components that are satisfactory to cope with those forces for their given loads. They will have advised their customers (e.g. caravan manufacturers) of the minimum specification tyres to use to keep the trailer road legal and safe.

Companies can of course get it wrong sometimes, but for both the chassis manufacture and teh caravan body manufacture to both get it wrong is a diminishing probability.

Absolutely, completely agree, but as you say. “Minimum“ specification.

All the OP needs to do is source tyres of the same specification.

In the first case the OP did not fully quote the tyre markings or mention that it was a twin. But the answer in the form you suggest was clearly provided by myself and others in the first few posts.

This was then extended into a fuller discussion typicle of many/most forum topics and what sets them apart from a Q&A. Confusion was introduced which is worrying as these are people who choose and specify for their own caravans.

(Please expand the quote above)

To give yourself and others a sense of what is meant by the supplety of tyres. I once questioned Michelin as to why a brand new caravan I had had greatly improved towing characteristics when I changed the car over to mid range quality tyres. Michelin wrote to me to say They were fully aware of this. It is due the the increased supplety of the side walls in premium tyres which helps maintain a flat tread across the tyres width for greater road holding. This has a detrimental effect when towing as the rear of the car now moves from side to side more. This action is exaggerated in the trailer. To be fair to Mitchelin. I have had them since, in fact I have them now problem free. This same supplety could well be an advantage on a twin axle van. (I surmise).

Hope this clears it up for you.

John
 
Mar 14, 2005
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The question was about tyres for a caravan, not what is fitted to the tow vehicle.

The way I read the CMHC comment is they are not "recommending" upgrading tyres, they are simply saying there is no practical difference except the owners perception of safety. There is nothing wrong with continuing to use OEM specification tyres.

When used on caravans, there is no clear evidence that show cheap tyres lack sufficient grip, and as the vast majority of caravan tyres are not worn down but become unserviceable due to age, it is highly questionable if going for a more expensive upgraded tyre is a justifiable expense.

The OP should just stick to the OEM specification.
 

Parksy

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Nov 12, 2009
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This thread is moving far from the O.P. and is starting to degenerate into some sort of points scoring exercise.
It's not in the interests of this forum to act as a sniping platform between members, so unless anyone has anything constructive to add it's time to move on.
The OP has been answered, explanations and opposing arguments have been aired so everyone interested has had their say.
 
Jun 16, 2020
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The question was about tyres for a caravan, not what is fitted to the tow vehicle.

The way I read the CMHC comment is they are not "recommending" upgrading tyres, they are simply saying there is no practical difference except the owners perception of safety. There is nothing wrong with continuing to use OEM specification tyres.

When used on caravans, there is no clear evidence that show cheap tyres lack sufficient grip, and as the vast majority of caravan tyres are not worn down but become unserviceable due to age, it is highly questionable if going for a more expensive upgraded tyre is a justifiable expense.

The OP should just stick to the OEM specification.

I apologies prof. You clearly totally miss my point and did not follow the purpose of the analogy. You clearly have a different interpretation of the links than I do. In my opinion, the OEM spec IS (I have never suggested differently), correct but only part of the sensible purchase. If some are content to settle for the minimum then no doubt that is what they will get. On matters of safety I would rather investigate the options and find a better solution.

Please do not criticise me for doing so. Rise above that.

This thread is moving far from the O.P. and is starting to degenerate into some sort of points scoring exercise.
It's not in the interests of this forum to act as a sniping platform between members, so unless anyone has anything constructive to add it's time to move on.
The OP has been answered, explanations and opposing arguments have been aired so everyone interested has had their say.

I do agree, but the OP did receive excellent answers to his question.

I, for one will leave the subject.


John
 
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