Is 215/35/18 safe on these vans?

[aulday]

oh pants pie.

So for example the tyres spec of say:

500KG's, x2 =1000KG's. on a FRONT axle weighing 850KG's
and
500KG's, x2 =1000KG's. on a REAR axle weighing 900KG's, for example.

That is cutting it fine for this example, but the tyres specification has been designed to MOVE that load safely. Isn't that okay?

Sorry to drag this out but it's just numbers and safety-ratings surely

[kevtherev]

...you're taking a right hand bend, something causes you to brake hard on the bend.
the whole weight of the van is shifted to the front nearside tyre, the pressure inside the tyre instantly rockets, the tread lifts off the road on the inside as the tyre loses shape, it wants to beak free and go sideways... where are the shared loads there?

[aulday]

well yeah but isn't that all included in the tyres safety test. As in the rating is for safety, and accounts for harsh braking and hazards etc.

Or do you have to get much higher rated tyres than your vehicle weight in general, because the don't account for anomalies?

[aulday]

And do profile tyres hold their shape quite well due to the short side wall or is that not how it goes?

[aulday]

Helium in my hi-top!!! that'll make for cheaper rubbers!

[kevtherev]

well yeah but isn't that all included in the tyres safety test. As in the rating is for safety, and accounts for harsh braking and hazards etc.

yes it is your right.. that's why T25 tyres are safer above 97 load rating. these tyres are constructed much differently to car tyres, they are "reinforced" they employ harder compounds of rubber, extra layers of nylon chords around the steel belt to stiffen up the tread and sidewall, help move heat from the sidewall, to stop the tyre losing it's abilities to keep the tread foot as large as possible.
Larger load ratings such as 104 are 8 ply construction meaning that they hold their shape even better, to keep as much of the footprint of the tread on the road .

[kevtherev]

Ultra-low profile tyres (tyres with a number below 50) generally require a higher inflation pressure than taller profile tyres. This is due to Ultra-low profile tyres having a smaller internal volume and hence in order to carry the same load, these tyres require more pressure.
Which in turn means aquaplaning is a problem and the ride would be VERY harsh.

The only advantage I can see is the cornering and traction on dry tarmac would be great, downside is wear on the tread would be excessive and replacing them would be sooner rather than later... not cheap either.

I just replaced my Pirellis they cost me £95 each 215/60 X 16. R 97
they were fitted 5 years ago but changed now due to them being out of date, but still with a 5mm depth tread left
They covered over 40,000 miles

[AdrianC]

And as for moving, surely they rate tyres with the premise that the load they are rated for will move. It wouldn't be valid otherwise surely, as they are tyres. And that's their purpose..?

Surely they rate a tyres max load on the condition of it starting, stopping and cornering?

Tyres are rated to carry <load rating> kg at <speed rating> mph.

Your van is rated to carry <gvw> kg. It's also specified (have a look at the tyre pressure plate, if it's still there) for tyres of minimum <load rating>.

[aulday]

I'll probably try and get 4x 93W's I'd feel safe with that if my van weighs under a ton per axle when I check it.

With all this said. I've seen 3 or 4 people on this thread with 40, 35 and even 30 profile tyres on theirs.

http://www.brick-yard.co.uk/forum/defin ... page3.html

I take it they're just silly billies?

thanks for all the advice so far

[AdrianC]

With all this said. I've seen 3 or 4 people on this thread with 40, 35 and even 30 profile tyres on theirs.

The size isn't the issue. The load rating is.

[kevtherev]

I take it they're just silly billies?

thanks for all the advice so far

No they're not silly billies. Like I said earlier it's your van.
I just like to give you all the information to make an informed descision about the safety of your family/loved ones.
Maybe those others have done the same. Who knows.

Me.. I couldn't stand the guilt. Or live with the consequences should the worst happen.
Nobody here will endorse fitting, below weight tyres, at least I hope not.

It's a risk you alone must stand by.

[aulday]

With all this said. I've seen 3 or 4 people on this thread with 40, 35 and even 30 profile tyres on theirs.

The size isn't the issue. The load rating is.

You don't generally get anything over 93W with a profile lower than 45. So they're almost def running under weight. If it weighs under 1000KGs per axle, I'll get 4x 93W. That's rated at 1300KGs per axle, so should be fine.

[aulday]

hang on

Am I restricted to 215mm tyres on my 7.5 wide rims?

I thought all along that I can't go wider. If I can then this will open up my tyre market greatly.

Anyone know?

[AdrianC]

You don't generally get anything over 93W with a profile lower than 45.

Mebbe not as narrow as 215, or as relatively small rim as 18 - but if that was the case as a generality, I wonder what all those 4x4s are on...?

A quick look at Camskill shows 35 profile as high as 110 load - but a big chunk heftier - 315/35 20

'course, it all just sounds to me as if it's another reason not to use these particular rims - especially since they aren't even the right PCD...

[aulday]

well I've seen loads of 225 and 335 width tyres for a good price with a profile 45 & 55. rated at 95w+ so I think I'm in luck!

I didn't know they'd go on a 7.5j rim but they will.