Just obtained some old NATO tyres to tide me over for a few years and noticed something interesting on the sidewall.
These are Radials and I know the ply rating that applied to older bias ply tyres do not really apply - I assumed the 12ply rating on the sidwall was merely a means of comparing these radials to the older bias ply tyres.
But is this correct ?
I also noted that it states 3 plies in the tread and 1 ply in the sidewall - so that gives 4 plies ?
Maybe New Math or some shonky marketing :devil
Not that it matters, just curious :laugh
i may not explain it well .
ply rating was a way of telling you the load capacity of the tyre .
back then with bias ply tyres, the more plys in a tyre , the heavier the load it could carry .
it was carried forward as a ply rating , so people had an understanding as to what the tyre could carry .
unfortunately this actually confused the hell out of a lot of people.
look for a load rating . which is a letter of the alphabet .
even better google tyre markings , or something similar .
i am sure it will explain better than i can .
Nice article sdibaja Explains it well - even mentions cotton (canvas) used to be the material of choice :eek
Another thing to note is that bias ply tyres are by no means a thing of the past. By using modern materials, they still have a role to play and is tough as nails :smile
So, all in all, the 12PLY rating is, as I thought, a marketing gizmo - 12 sounds soooo much better than 4 :devil
Such a good concise article, I decided it is worth capturing for posterity.
G,,day , i do not mean this in a nasty way ,
i will preface this first . i have had a bastard of a year , looking after a dying mother , a friend , vietnam vet comitting suicide .
it has knocked the shit out of me .
but i am trying . also trying to help others as others have helped me .
it is a bit sad when i try to help with info , and am totally ignored , it hurts when i am down .
i do not own a mog , but have had a bit to do with them .
politeness and manners go a long way .
if you find this offensive , oh well , i am speaking my mind .
i will most likely stop giving any advice or comments ,
Kerry,
I read what you posted and found it informative.
I am sorry you have had a tough go of it lately, but, at least for me, your response contributed to the discussion and fundamentally answered the question.
SDI's post followed up with a result from the web (your suggestion), and then hilarity ensued...
I don't think there was any ill intent of not replying to you directly; instead just including your comment as part of the ongoing discussion. This is a small group and we are all pretty used to each other (mostly), and usually just keep moving the discussion along, rather than addressing each response. Think of it more like a bunch of folks around a campfire. Forgive us that if it offends.
Kerry, Ditto from me. You should in no way feel your contribution counts for nothing. Every bit helps and is appreciated by all.
You will find a similar humorous streak in many other posts which is directed towards the topic/issue and no person in particular. We are a diverse and crazy lot (after all it involves a crazy vehicle), we are generally very supportive of each other and crazy humour is a part of that.
I trust things get better for you soon, but in the meantime enjoy the forum - perhaps even draw strength from it.
Cheers
OK, back to tyre issues. I thought of starting a new thread, but then decided the new issue still fits the original. Problem what valves to use. I want to use the clamp-in style as they are more resistant to damage when off-roading. The WSM and pocket data book makes no mention of valve dimensions. Also could not find anything on the forum.
So, the tyre company tells me they do not carry clamp style valves and I had to order them separately. Although I should not have been, I was however again blown away by the plethora of different valves on the market :eek
However, it seems that there are 3 common hole sizes for trucks;
.390
.453
.625
From doing some external measurement on my rims, it looks like the mog is 0.390 (9.7mm)
There is a European body that deals with rims and such called ETRTO and they list type number V3-20-1 that looks the part. However, I could not get any and opted for what I think will also work - valves made for Alcoa aluminium rims that also uses a 9.7mm hole. I could not find dimensional drawings on either of these to do direct comparison and it seems the main difference is that the o-ring is specificaly formulated for aluminum to prevent corrosion. The Alcoa style is shorter which I like.
Can anybody confirm if this will work or whether ther is some silly little thing that prevents it from being applicable to the Mog rims ?
"ETRTO" stands for the European Tyre and Rim Technical Organisation which is a standards organization for rims and tyres (as well as valves). The V3.20.1 valve is in the V3.2X.X series made for 9.7 mm valve holes for commercial applications. I have attached a technical drawing of the V3.2X.X series you may find helpful.
Here are the ISO equivalents:
ETRTO -> ISO
V3.20.1 -> CP 01
V3.20.4 -> DP 01
V3.20.5 -> DP 02
V3.20.6 -> DP 03
V3.20.7 -> DP 04
V3.20.10 -> DP 05
I cannot 100% guarantee that it will work - but it is listed as compatible with commercial vehicle rims with a 9.7 mm valve hole.
Thanks Logonwheeler - that helps.
My spare looked different and I finally worked out what was going on. It has a air/liquid valve. I guess they must have drilled out the hole to 5/8 to suit :eek
I would not worry about deterioration of rubber valves. I have both rubber and metal ones on my Unimog ( got two valves on each tyre) and have not had any problems with either. I get new rubber valves whenever I get new tyres, so they are seldom more than 5 years old. I have always had rubber valves on all my vehicles without any problems. I think the tyres will be cactus long before the valves.
I use the 24106 valves and carry spares of those. I tore off one of the longer ones and bent another in the mud once. The ones I purchased are very high quality but brass not stainless. For me, shorter is better for where I've been.
Have a great day,
Chas
Thanks Chas, that confirms it for me.
Iain, you are right in replacing the valves every 5yrs or so. I suspect any longer carries a risk. A small relatively cheap component can lead to big hassles later on.
It all comes down to quality of course. Personally, I am happy to pay a bit extra if (and this is a big IF) the quality is better.
Rubber is the worst in terms of quality guarantee. Much of what we are offered for sale nowadays has unknown origins. When you start asking for EPDM and VITON, the situation improves and often quality is assured.
Pics show rubber o-rings that has been in my possession for less than 5yrs. Of particular concern is the DOT air connector - Made in Brazil - of which I have several on my mog. Replacing the external o-ring is easy, the inner o-ring appears more problematic and I have yet to try. This does show however that even DOT approved components are not guaranteed quality.
By way of comparison, the rubber sleeves that hold the speedo and instrument cluster in place is original (over 30yrs old) and in perfect condition !!!
Buyer beware has never been more true :devil
Following on from previous post - did some digging and discovered that the connectors with cracked o-rings are from a company called Detroit Fluid Power. Appears they use Buna-N o-rings. This brand is also sold locally under the General Pneumatics banner.
Since then I have been using Raufoss which uses EPDM orings. More expensive and not locally available, but......
What connectors are they Pieter, I have used the WIRA Push Fit Connectors on every part of my air system, the are very easy to install, and all except the 18mm one are easy to disconnect and reconnect. This makes it really easy to change things I get mine from Air Brake Systems, usually overnight delivery.
Maybe you said but what is the mog used for? I have discovered a few things about tires when used in offroad, forest, or ranching situations. Bias ply scores big points for tough sidewalls. I blew way too many Michelins trying to do forest work with them. Weak sidewalls. Other radials are the same way.
Metal stems, the screw-clamp type, are fine until a rock or a stick bends or breaks them, then they leak. Rubber stems, if not 30 years old, will bounce back.
For any application where the going is tough, Bias ply and rubber stems are the way to go, IMHO.
On the road, radials rock, and screw-clamp stems do fine, but I still like rubber stems.
If you use the metal stems, keep them as short as possible to avoid harm.
Be aware for some applications, rubber stems are not allowed/rated at higher pressures, like on a trailer. A quick search finds limits of 60, 65, and 75 psi. One tire shop refused to air up one trailer tire with a rubber stem because I wanted 80 psi in a 90 psi tire. Have to use the screw-clamp stems for high pressure (probably few Unimogs run that high pressure).
Hello Ian,
Mine are all push-fit as well.
So, the bad ones as per my previous post are made by Detroit - sold here by many truck shops under the General Pneumatics brand - AVOID
Your German made ones are probably also good :wink
I have switched to Raufoss - also used by Wabco - mine supplied by AV
Seems TUV certification might help with quality. They are an independent lab that test stuff - like UL in the US.
Well, not quite new - but new to Mog :devil
As it turns out the one rim with the larger valve hole is not the greatest - it has some lateral runout - perhaps this is not unusual for liquid/air rims ??
So I have decided to run with the old valves till I get new tyres and a replacement rim which is of better quality.
I have the tires at 45psi for now and they look almost over-inflated ?
Overall, I am happy with them. Wobbles are gone, slightly lower rolling resistance (I think) but still fairly noisy.
Turns out my gutfeel on the XM47s age was warranted. One has long internal cracks.
I will see how I go, but I am liking the 12.5 size. Does not look as mean as the 405 s - but.....My Mog only hits 4600kg on the scales, so big boots are probably not required.
I was quite surprised to see the tires being fitted using no bead blasting - just inflation through the valve pushed the beads into place. Good to know it can be done simply.
Those Conti NDT tires are excellent off road, snow, ice, mud, and are tuff!! You made a wise choice.---) Last a long time an run smoothe.
tlane
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