Conti Camper tyres Blow out!

yeoblade

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This tyre split whilst in France last week, luck would have it that we were only going 30mph on a small side road when it went bang!
1/2 a mile down the road we pulled into a farm and a the couple running it were from Scotland :)
tyresplit.jpg

with a 5 ton bottle jack and 36"stilsons on the wheel brace we finally got it changed and on our way.
I had called Nationwide Bank breakdown but that's another story.
Now I'm home I was worried I'd overloaded it, to the weighbridge and with the scooter in the back and eBike, full diesel 1/2 water weighed in at 3,760Kg my van Maxi/chasis Ducato plated at 4,005KG.
Rear axle plated at 2,400Kg and weighed in at 2,370Kg, so JUST in !
Conti 16" tyres are only 116 load rated ie. 1,250Kg x 2 = 2,500Kg on the back, not a lot of leeway.

I have been to the tyre fitters today and got the front and rear wheels swopped over, so the Conti Vanco campers are on the front and Avon AV11 are on the back as they are rated tyre index of 121 ie, 1,450Kg x 2 = 2,850Kg a much safer margin.

Also the tyre that burst was at 5.5 bar 80psi as per Swift OE sticker on door jam, I noticed the Conti tyre is actually marked as max pressure only 69psi !


tyresplit.jpg
 
As above, the max pressure isn't the actual that Conti recommends.
Having higher rated tyres on the rear will be no bad thing, but the rating of the originals is supposed to be their safe working load, so being inside this should not be a problem.
 
Max pressure on the tyre is the maximum pressure that tyre fitters will inflate a new tyre to.
As you have found if you have c2.5T axle load you need 10 Ply Rating tyres for the sustained higher load and pressure.
 
80 PSI is a huge pressure. Go over a bump or pothole and that will skyrocket. Check what Swift say, weigh laden front and rear axles then contact tyre manufacturers to ask what they recommend. It's not rocket science for them.

I did that and was pleasantly surprised that they recommended much the same as the manufacturer, 60 front, 65 rear, which had seemed rather high to me for my 3.3 tonne van, but I was inexperienced back then.

I think that the manufacturers choose pressures to cope with the plated axle limits. Probably they have to. If you are running somewhere close to them they'll be about right, but if you are running lighter they might not be optimal. Best to weigh, contact manufacturer and ask advice. Running at too high a pressure can be as detrimental as too low. Just as car manufacturers usually specify a range of pressures depending on load.

Make sure they have fitted the proper solid high pressure valves, standard car ones can blow out, they are not rated for it, which is disastrous. Easy to check, if you can flex the rubber its not high pressure, it should be solid metal inside. Also fit metal valve caps, if the valve insert fails it might blow off a flimsy plastic cap.

I really do think some "Camping tyres" can be over priced, as does my tyre fitter, never heard any plausible explanation of what makes them so special and different.

Alternative viewpoint here, which also explains that 80 PSI is allowed on the Conti. Vanco Campers for motorhome use. Stamped on the tyre, picture of a motorhome and max. pressure 5.5 BAR i.e. 80 PSI:


Perhaps you have just been unlucky, tyres do blow out, sometimes inexplicably. Invisible sidewall damage from e.g a slight kerbing I suspect being a common cause. Anything running at 80 PSI is under a huge strain and the tiniest leak from inside is likely to blow off the outer layer of the sidewall in the way you've shown. On a car tyre it might just bulge or blister.
 
Send an email to Conti Technical saying what happened and give them the info you put here. They are very good and I had extensive contact with them when trying to get a tyre suitable for my updated van on 15’s.
my rear axle is very close to yours, rated at 2430kgs, and they told me to use 4.5bar not what anything else stated.
 
Send an email to Conti Technical saying what happened and give them the info you put here. They are very good and I had extensive contact with them when trying to get a tyre suitable for my updated van on 15’s.
my rear axle is very close to yours, rated at 2430kgs, and they told me to use 4.5bar not what anything else stated.

A good idea, I will. Who did you email?

Interestingly I was also a bit concerned that the conti's bulged so much at 80 PSI and max axle load on the back.
The Avon's now on the back don't bulge hardly at all and the Conti's on the front don't bulge now either, all looks a lot better all round.

It's a sod to change the back wheels, the coach work gets in the way of taking the wheel off, with the air ride bags up max it helps push the axle out away from the van. Tyre fitter in the end had to break the bead on the tyre, to make it narrower, fit on van then reinflate after. One hours work just to swap wheels around and he was sweating like a pig when finished.
 
As above, the max pressure isn't the actual that Conti recommends.
Having higher rated tyres on the rear will be no bad thing, but the rating of the originals is supposed to be their safe working load, so being inside this should not be a problem.

Agreed, the load rating, sometimes a dual rating which I don't properly understand, is supposed to be quite safe fully loaded running at the maximum rated speed (106mph in my case, I wish) in the worst conditions, road surface burning hot, air temperatures in the forties, for sustained periods.

I usually pootle along at about 60 mph, or 50 in France respecting the speed limit. So I don't worry at all about them being over-stressed, they are built to take far worse. I'm sure there will be a safety margin included too.
 
This was our continental 113/111 manufactured date 2012 luckily it went down slowly after being parked up for 4 days in Spain I put it down to high temp and motorway speed

DCE72F7F-9610-4BC0-BFF8-4D0C7E1B2682.jpeg
 
80 PSI is a huge pressure. Go over a bump or pothole and that will skyrocket. Check what Swift say, weigh laden front and rear axles then contact tyre manufacturers to ask what they recommend. It's not rocket science for them.

I did that and was pleasantly surprised that they recommended much the same as the manufacturer, 60 front, 65 rear, which had seemed rather high to me for my 3.3 tonne van, but I was inexperienced back then.

I think that the manufacturers choose pressures to cope with the plated axle limits. Probably they have to. If you are running somewhere close to them they'll be about right, but if you are running lighter they might not be optimal. Best to weigh, contact manufacturer and ask advice. Running at too high a pressure can be as detrimental as too low. Just as car manufacturers usually specify a range of pressures depending on load.

Make sure they have fitted the proper solid high pressure valves, standard car ones can blow out, they are not rated for it, which is disastrous. Easy to check, if you can flex the rubber its not high pressure, it should be solid metal inside. Also fit metal valve caps, if the valve insert fails it might blow off a flimsy plastic cap.

I really do think some "Camping tyres" can be over priced, as does my tyre fitter, never heard any plausible explanation of what makes them so special and different.

Alternative viewpoint here, which also explains that 80 PSI is allowed on the Conti. Vanco Campers for motorhome use. Stamped on the tyre, picture of a motorhome and max. pressure 5.5 BAR i.e. 80 PSI:


/////........

Ah that's where the 5.5 bar comes from, thanks. Swift recommended pressure is 5.5 bar front and back according to the label fitted, I do run them at the max recommended pressure as I know I'm always near max weight, 4 tonne, with the scooter in the back I always go to a commercial/truck fitters place as I believe they have a better understanding of heavier vehicles than the average quick fit fitters place.
 
Ah that's where the 5.5 bar comes from, thanks. Swift recommended pressure is 5.5 bar front and back according to the label fitted, I do run them at the max recommended pressure as I know I'm always near max weight, 4 tonne, with the scooter in the back I always go to a commercial/truck fitters place as I believe they have a better understanding of heavier vehicles than the average quick fit fitters place.
I believe the 5.5barr is the recommended pressure for running at max weight, the Fiat plate on my Maxi chassis PVC shows same IIRC.
 
I hate posts of this type .
Chausson,Swift,Hymer and all the rest do not make tyres.
My advice would be not to believe the sticker they stick on a door post.. it might have been right when they built it with the upgraded tyres they fitted, though the tyre make is not stated and people change tyres.
I have Toyo H08's on mine, they dont get fitted by any motorhome manufacturer .( it's a ci mizar)
 
You do need to read the tyrewall - max load is achieved at the max pressure.
If you have axle load near the maximum allowed then you will have to be near the max pressure.
Michelin consistently say that the pressure for rear tyres with their camping tyrtyres is 85-90 psi - apparently without regard to the actual weights.
I think this is because they assume you have tyres matched to the axle load and so will need getting on for maximum pressure.

There is some difference between their camping and standard van tyres.
When I bought bigger stronger tyres to match the 2.25T on my back axle I ended up with Michelin Agilis C type (118 load rate) rather than CP (because having ordered them online I hadn't spotted the difference before they were fitted. When I asked for them to be inflated to 90 psi specified by Michelin for camping tyres it was refused because 80 psi is max for standard van tyre.
Anyway I'm living with those tyres and they seem fine - can't really say if they make any difference in running compared to the camping tyres (113 capacity) they replaced. They should see me out with a bit of luck!
These old tyres did have max pressure 90 psi allowed and are now on the front if the van at 60 psi.
The new van tyres are 10 Ply Rating and so are good and strong.
I will be buying Camping when I replace the fronts because to be honest there's not a massive premium between the two Michelin types and I'd rather not have to buy another pair when I discover that there is a ride quality-handling difference at the front where all the work is and we're sat on top of them.
 
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Note to Sharpie about dual load rating - the lower figure is when two tyres are on same hub.
 
I’m a big Michelin fan when the factors are critical. In my early truck days we used to take all the new tyres off (new vehicles). We then only ever put new Michelin’s on all trucks on the front axle (using the new ones off new trucks) with other brands or re cut tyres on the other axles. As the business got bigger this got less practical.
 

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