Are Runflats worth trying to save???

[162tcat]

Do you happen to know the nsn on those mrap rims? I'd love aluminum rims on my 5 ton

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[Jason Firm]

That's a reasonable price to pay for a stud, but I am talking 'Mercedes' and a Unimog to boot!. Everything is incredibly expensive (especially here because they are rare). Who's going to risk buying an aftermarket set of studs for a truck? not me.

 

[gringeltaube]

Please...

 

[red]

Do you happen to know the nsn on those mrap rims? I'd love aluminum rims on my 5 ton

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No idea on the NSN for them.

The runflats/beadlock that came on them are a 5 piece setup. The 3 runflat parts bolt together, then there are 2 1" rubber spacers that go between the assembled run flat and the bead of the tire. Pics in post #129 http://www.steelsoldiers.com/showthread.php?132200-quot-Rescued-quot-M816-Wrecker/page13

 

[74M35A2]

After reading this, I'm now considering to run the run-flat inserts on my two fronts, soon to be 16.00-20's. If anybody has 2, please get ahold of me, thanks. Would need whatever it takes to make it work, bead locks, or whatever.

 

[simp5782]

After reading this, I'm now considering to run the run-flat inserts on my two fronts, soon to be 16.00-20's. If anybody has 2, please get ahold of me, thanks. Would need whatever it takes to make it work, bead locks, or whatever.

Your tires already have them re re

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[Jason Firm]

Run flats

Hi everyone. I have some more info from one of the Hutchinson experts and which I did not know. Apparently the goop inside the tyres is a special heat retarding lube. In wheels with run-flats, without the lube the tyres will burn up. If a tyre is changed or it all leaks out, the lube needs to be replaced (and is expensive). The rims I have purchased are designed for the vehicle in the photo. They are Hutchinson USA military specification two piece removable face rim; outer component model W0-1137 B 20X10 with inner component model WI-1137 F combined with the Michelin XZL 395/85R20 tyre and a Hutchinson run-flat. The Hutchinson mil spec 'O' ring to suit this rim is Part Number 50015.
Also, When re-assembling the wheel, the donut run-flat needs compressing in order to re-fit the face plate. Some owners fit longer bolts at every second hole as standard, as the odd longer bolts allow some nuts to be screwed on first and to compress the front plate down enough so that the rest of the nuts can be fitted. If you do need to change a tyre on a wheel fitted with a run-flat and you don't have these odd longer bolts, you will need to take the wheel to a place which has a large press, of a type suited to changing these tyres.
Anyway, hope that helps in some way

 

[acme66]

God no. I like the beadlocks because it isn't as hard to get the tires to seat but I would never mess with runflats. Should be an adventure getting them out.

Ken

 

[someoldmoose]

Just gonna reiterate what I've said before, IF you ever experience a rapid deflation ( blow-out ) of a tire on a steer axle at Highway speed and DON'T have a run-flat insert, May whatever deity you prefer protect you. IF you survive the situation in the previous sentence, you WILL wish you had them and / or get them installed. The life safety value ALONE is worth any difficulty involved in "dealing" with them. Not to mention the legal liability if, preferred Deity forbid, someone is killed or injured during a blow-out event. Lawyers LOOOOOOOOVE these. Trucks are da' Devil, easily vilified in litigation, . . . privately owned ones EVEN MORE SO. IF you hate the one piece hard rubber ones so common in MV use, I do too so scrap them. But PLEEEEEEAASE, I beg you, replace them with the 2 piece "bolt-on" design (Tyron, or similar). The life you save might be mine or a member of my family. Here endeth the sermon.

 

[acme66]

When I lost a steering tire I admit it was a ride but it didn't yank the wheel out of my hands or rampage through the village. It was a 1400/20 Michelin X that decided suddenly not to be a tire anymore. It is a situation worth serious consideration and caution for sure but I believe you are trying to use fear to leverage your position. If I had them I would still remove them and I have driven a blowout. Well honesty it would run the tire as is until bald then toss the toss the tire. If I had to remove the insert to fix the tire however I would not put it back in.

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[someoldmoose]

I'm not trying to "leverage" anything. Just offering advise based on decades of experience as a professional driver AND a firefighter who has to cut the remains out of crushed vehicles after bad stuff happens. I'm glad yours turned out well. You were obviously paying attention and knew what to do when it happened. For those that do NOT are you interested in being around them if it happens to them. I am not, but I will come clean up after.

You don't want em ? Cool. Ya pays yer fee and ya takes yer chances. Good luck & Happy Motoring.

 

[acme66]

I thought about my post. First I never should have referenced the Lord flippantly and I know better. Lead off with the experience you have to give a reference to where your position comes from. I have a tendency to tune out a comment coming from what I see as a sky is falling attitude. I need to remember sometimes the sky is actually falling. I also feel like I need to talk about the loss of a steer tire more. It was another Michelin carcass failure. There was the smallest moment of warning where I could hear rubber chunks start hitting the inner fenders before it simply stopped being round. Half a second or less but an important warning anyway. The front of the truck dropped and began to shake violently. I did not hammer the brakes and simply let it ride out slowing down. I was willing to accept body damage to mantain control. Turns out there was none but still. Also that tire did have bead lock and that was important. It means the tire stayed on the rim and turning even when the brakes came on. Without the lock that tire could have turned sideways and it would have been worse. I think if these are on the front and you can't locate bead lock inserts to replace them then you might think about putting them back in. I would mail order beadlock inserts before I did that however.

Ken

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[someoldmoose]

Only thing I'm pushing is safety my man. No offense taken by me, fer sure. Appreciate the re-exam though. Too many people buy these monsters and have never driven anything bigger than Cobalt. Two VERY different worlds. Good on ya mate. Keep the shiny, er flat side up.

 

[Special T]

I would add that application is everything. If your Gina drive loaded through Seattle and attempt 60mph the run flats are likely a good idea. If your out in the country and mostly on country roads and or it's you toy that you "wheel" probably not.

I'm amazed at the number of blow out stories I hear on this forum. Up here in the NW the temps are so mild & I don't think people work their MV quite as hard...

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[simp5782]

a 395 with a runflat installed after 5 hours of driving at 58/60mph with outside temps in the 85 to 95 degree range has a temp of 145 degrees. Even with ambient temps of 80 and it raining the tires still see 90 degrees and will let off steam. I have had more blowouts on run flat tires due to heat than a tire without a runflat. Military tires weren't meant to run runflats on the pavement, Meant to take a bullet and keep on going. Unless you live in like Detroit or Chicago or one of those other gunshot tire prone areas then you may want them.

 

[gringeltaube]

....................I have had more blowouts on run flat tires due to heat than a tire without a runflat.

I'm trying to understand how these inserts can make a tire run hotter than the same tire without runflat.

Knowingly, heat (above ambient temp) comes from friction. But besides the inner friction of the carcass due to tire flexion, there should be nothing else causing any friction (= heat), with or without runflat. Under normal highway conditions, no contact between the tire carcass and the donut itself should ever occur.
So the only other possible explanation I can find is, that part of the heat would normally dissipate through the wheel rim (?), and that this would be hindered with that thick layer of rubber acting as insulating material (??)


BTW, does anyone know the actual outer diameter of a Hutchinson 1-pc rubber insert for the 395/85R20s?
I have only seen those in pictures; I bet it is not more than 30" o.d.? If so, then there would be a distance of about 5" (at the 6 o'clock position), before both surfaces in question could ever touch. That is considering the static loaded radius, of course.


Interestingly, the Hutchinson donuts for the 37" HMMWV radials have seen a reduction in diameter, over the years: the early Goodyear MT came with a 2-pc rubber runflat, measuring 24" o.d., while the newer, 1-pc runflat insert is only 23". Must be the reason that it says LOW PROFILE on its side.
The inner diameter of a MT/R or BAJA T/A is about 34", so that leaves us with a gap of roughly 4" (loaded to 75% @ 60psi).
Again, hard to imagine that it would ever touch, running on the highway.



G.

 

[simp5782]

Engine torque can cause severe heat rises in the run flat being that it cant dissipate like you said. They add that black goo crap like the Aussie said to keep the heat down. The few I have broken down lately have had some of that crap in them and some haven't I am assuming it dried up or just wasn't put in. The 2 blowouts I know did not have any of that residue coming out of it. I also am putting a lot more weight on the tires with the trailer plus traveling at speeds over their rated limit. I just did an interstate run at 64mph for about 4 miles tires were at 94 to 98 all the way around. The other day after a run with a M915 on the trailer after getting off I75 my rear tires were reading 145 to 155 and the fronts were at 110.

 

[someoldmoose]

Won't debate anybody's experience but heat building up in a tire comes from only four sources. Overloading. Underinflation. Driven "too hard" (faster than the speed rating). Overheated brakes. That's IT. Science FACT. One is bad. All four are a sure path to boom. ( Wes, ya just pretty much "admitted" to TWO - possible overloading and high speed, not a bash -- your words)
The inserts can NOT make a tire overheat. Tyron has mountains of data proving same. All Euro OTR and Emergency vehicles are REQUIRED to have them. For safety. First, last, and always. We all talk about "protecting" our hobby. This is an EXCELLENT way to do just that. Use run-flat inserts. Avoid being a Headline or Lead news story.

Or don't, your choice. For now. 'Murrrka !!!!

 

[Special T]

Load, inflation, speed & duration are the 4 corners of heat build up and tire capacity.

I'm 90% certain that goo on the inside of the tires in commercial tire soap like Murphies or others.

The run flat won't generate heat but it will absorb and retain heat buildup.

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[someoldmoose]

T, agree completely. The key is to not generate any more than necessary.