FROM: jgh@hopper.unh.edu (Jeffrey G Hemmett)
SUBJECT: Re: snow chain - front or rear
DATE: 25 Mar 1998 20:32:03 GMT
ORGANIZATION: University_of New Hampshire

In article <3519e3a6.594202788@news-pnh.mv.net>, Peter D. Hipson wrote:
>
>On Tue, 24 Mar 1998 23:40:26 -0800, Michael Lim 
>wrote:
>
>>I would like to get some advice on whether to install snow chain on the
>>2ront or rear wheels of a 97 Pathfinder 4x4?  Of course if I install
>>them on the front wheels, then I should be in 4WD mode.  I've asked
>>Nissan and they strongly advice on only installing on the rear wheels.
>>
>>Any comments?
>
>Sounds like you answered your own question: ">Nissan and they strongly
>advice on only installing on the rear wheels"! 
>
>Why do you want them on the front wheels? (I assume you are looking
>for someone to counter Nissan's comment) Probably there are clearence
>problems with the front, so be very careful if you try it. Check to
>make sure you don't destroy the stearing, and other components, or
>that the chains don't get broken, and then trash your wheel wells. 
>
>Excepting for certain conditions, and places, good driving practices
>are much more important than tire chains! Rather than chains, I'd
>suggest a more agressive tire might be the best solution for your
>problem
>

Want to know the reason to put them on the rear only if you've got 
only 1 pair?  Going downhill.  

You'r out on a nice snowy trail, and you put your only pair of chains
on the front wheels, since the chains multiply traction like you wouldn't
believe.  You figure it's sort of like the front wheel drive theory,
you'll have the best traction on the turning wheels to pull you through
corners.  You are right, and you laugh haughtily as you watch your rear
chained friends take corners wide, miss corners, and generally not have a
lot of directional control.  Then you come to a big hill you have to go
down. Your rear chained friends go down no problem, except a few missed a
turn in the middle and had to get winched back on track. Now your
gonna show 'em how it's done, figuring your front drive chains will pull 
you through the corner. You start down, and notice the hill is a little
off camber.  Then you notice your back end is swinging out, and catching
up to the front quite quickly. You now find you are going down the
track almost sideways, and finally enough snow gets piled up next to your
sideways sliding tires to tip the jeep over. On your side, you take off
sliding down the hill on your sheetmetal, plowing into your friends who
are standing in awe in front of their trucks at 30+, killing all of them
except one, who was off taking a leak.  But before it fully sinks in that
you have to find new drinking buddies, you pile into the side of a pickup
with those dreaded side tanks and blow up in a firery conflagration. If
there is such a word. Anyway, what happened?

Well, you forgot that your rear tires weren't passively following, like on
a true front wheel drive, they were spinning.  Spinning without much
traction.  This leads to sliding.  Your front tires, with the chains, had
great traction, and weren't going anywhere. The off camber nature of the
trail (and if not that then the corner would have) caused gravity to push
your sliding rear end down; you were an upside down pendulum, with the
pivot being your front tires and not enough traction in back to keep your
rear from coming around.  If you could go perfectly straight down a
perfectly even trail, with no off camber, your rear would have stayed
balanced behind your front. If you find a trail like this, let me know. 
Your rear chained friends, had they lived, would have explained to you
that their pivot was on the back, and so going down hill kept them in a
stable position.  Going uphill they are at a disadvantage, but they have
the added control of being able to turn the front wheels and control
to some degree the direction they are spinning, and therefore the sliding.
But not a whole lot (in a chained rear wheel drive car the front tires
aren't spinning, so altough still a bitch in snow up steep hills, not
nearly so bad).   

Anyway, upon returning from bleeding his lizard, your sole surviving
friend surveyed the scene and did what any intellignet person would do:
he took a pair of chains from one of his (now dead) friends rigs.  With
chains all around he was stable up and down hills, had chains pulling him
around corners, and also generally enjoyed a whole lot more traction than
he had before.

                                      - Jeff











From:             MTSOBCZAK@aol.com
Date sent:        Fri, 3 Dec 1999 21:41:12 EST
Subject:          Tire Chains Tips #21/MS (Long)
To:               landcruisers@tlca.org
Send reply to:    landcruisers@tlca.org

Prior post summaries on the use of chains I thought might be good to review -
Stay Safe for the holidays!!!

Chains - All four chained is obviously best, however, if you are going to run
just one pair, generally put them on the front for increased directional
control. On a steep slippery hill, you definitely want the chains on the uphill
end. Control is more important than traction. In the event the unchained end
loses traction, you want it to be the lower end of the rig so that it doesn't
try to pass you as it slides down the hill. The average speed should be well
under 10 mph and usually 20 - 30 mile per hour on dry roads. For even better
performance, try two chains on each tire with the cross chains offset. You could
also double up the cross chains on a single unit. Chains that are as TIGHT as
possible will get maximum life at 30 mph or less. 40 mph is about 57% chain life
and 50 mph drops it to 31% chain life. If the chains are loosened by just one
link, each side gives you 50% life at 30 mph 16% at 40 mph and 7% at 50 mpg. Do
not deflate the tires to install the chains. After installing them, driving
about 1/4" mile, stop and re-tighten the chains and never use them on "all
cable" type.

Regular tire chains (the kind that are shaped like ladders when they're 
spread out on the ground, with only two runners and a whole  bunch of rungs) 
have little or no effect on lateral traction.                   There are
certainly designs (such as "Diamond chains") which will keep more chain between
your tire and the ground, but plain old ladder chains do provide lateral
traction as well. If your tire is not turning, but is instead sliding, and the
cross chains are spaced and located in such a way that none are on  the ground,
then it's true they can't help much. So long as the tire is rolling, and you
have at least one cross chain in contact with the ground, the chains will help
your directional control.

Anyway, if you're getting one set, you're probably best off to put  them on the
back, because they won't make your steering worse than it would be without them.
 

For almost all use, especially on road use, if you run only one set of chains on
a four wheel drive rig, you should run them on the front. First of, because the
chains WILL HELP your steering, not hinder it..Secondly most of you braking
force is available at the front wheels, not the rear. At the low speeds that
chain use is appropriate for, this is where you want the bite to slow down. And
lastly, in low traction conditions, a chained rear end and an unchained front
end will tend to allow the rear axle to push the front in a turn. This will
result in under steer behavior. Sometimes extremely so. And it will not be
constant, or predictable. About the only time you should put chains on the rear
only of a Cruiser is for descending a steep slippery grade (mud, snow, ice or
whatever). In this situation you want to have your traction ability weighted
toward the rear. Otherwise you may find yourself in a situation where the tail
end simply will not stop when you apply the brakes. The front end will, but and
ruts or irregularities in the surface will allow the rear of the rig to slip to
one side or the other. Once it does, it will continue sliding downhill and spin
you right around. (Assuming that the slope is not steep enough to cause you to
tip over when you get turned sideways to it.) When climbing a steep slippery
slope you will of course get more traction advantage from the chains if they are
mounted on the rear. However if the traction capabilities of the front tires are
degraded enough by the snow, ice or mud, you may find the front end sliding back
downward if you get crossed up at all. And if you don't make the climb, and have
to back down, you are now in a similar situation to before, where you want to
have the most grip with the uphill axle. An improvement I have seen done to
ladder style chains is to purchase additional cross chains (normally sold for
repair purposes), and double up the number of cross chains. This gives much more
traction, both in the direction of wheel travel, and laterally as well.

Probably the biggest mistake that people make with chains is driving too 
fast. If conditions are slippery enough that you really need chains on your  4x4
, then 30 mph is TOO FAST. I seldom travel over 15-20 when the rig is chained,
whether on the road or the trail. Higher speeds will also wear your chains at a
geometrerically faster rate. Mark  Whatley 

Ice driving - I drove in low range and had very good luck in using the low range
in conjunction with compression braking, double clutch downshifting and some
gentle squeezing of the brakes (threshold braking).   I was able to stop in
conditions where I was not able to in high range, two wheel drive mode. 













Date sent:        Fri, 03 Dec 1999 23:33:35 -0900
From:             Trey 
To:               landcruisers@tlca.org
Subject:          Re: Tire Chains Tips #21/MS (Long)
Send reply to:    landcruisers@tlca.org


MTSOBCZAK@aol.com wrote:

> Prior post summaries on the use of chains I thought might be good to review -
> Stay Safe for the holidays!!!

> For even better performance, try two chains on each tire with the cross
> chains offset.

     Tire chains were not meant for this. If you can't get to where you need to
go with one good pair (or all 4s chained), then you really don't need to be
there. This is an unsafe idea.

> You could also double up the cross chains on a single unit.

    MUCH better idea. Have done this many times...

> After installing them,
> driving about 1/4" mile, stop and re-tighten the chains and never use them on
> "all cable" type.

    Never use "rubber adjusters" on "all cable" type.

> Regular tire chains (the kind that are shaped like ladders when they're
> spread out on the ground, with only two runners and a whole  bunch of rungs)
> have little or no effect on lateral traction. There are certainly designs
> (such as "Diamond chains") which will keep more chain between your tire and
> the ground, but plain old ladder chains do provide lateral traction as well.

    No offense but you contradict yourself. Your first sentence say's ladder
chains have "no effect on lateral traction" and the you say "plain old ladder
chains do provide lateral traction as well".


> If your tire is not turning, but is instead
> sliding, and the cross chains are spaced and located in such a way that none
> are on  the ground, then it's true they can't help much.

    You must have the wrong size chains for your tires then. A correct sized
chain will have 2 cross chains touching the ground when spaced correctly.

> Anyway, if you're getting one set, you're probably best off to put  them on
> the back, because they won't make your steering worse than it would be without
> them.

    This is sniped from you first sentence.....

<"All four chained is obviously best, however, if you are going to run
just one pair, generally put them on the front for increased directional
control.">

    Then you say...

> For almost all use, especially on road use, if you run only one set of chains
> on a four wheel drive rig, you should run them on the front.

    Your confusing...

> First of,
> because the chains WILL HELP your steering, not hinder it..Secondly most of
> you braking force is available at the front wheels, not the rear. At the low
> speeds that chain use is appropriate for, this is where you want the bite to
> slow down.

  Off road it will help steering and traction. As for breaking force, if the
front doesn't "grab" then your chained rear will.

> And lastly, in low traction conditions, a chained rear end and an
> unchained front end will tend to allow the rear axle to push the front in a
> turn. This will result in under steer behavior. Sometimes extremely so. And it
> will not be constant, or predictable.

    Slow down. We drive in snow and ice 5 + months a year :-)

> About the only time you should put chains on the rear only of a Cruiser is for
> descending a steep slippery grade (mud, snow, ice or whatever).

    Or daily driving on pavement.

> When climbing a steep slippery slope you will of course get more traction
> advantage from the chains if they are mounted on the rear.

    I disagree. I'd prefer the "pulling" tires to have the traction in this
situation verses the "pushing" tires for the very reasons you state below.

> However if the
> traction capabilities of the front tires are degraded enough by the snow, ice
> or mud, you may find the front end sliding back downward if you get crossed up
> at all. And if you don't make the climb, and have to back down, you are now in
> a similar situation to before, where you want to have the most grip with the
> uphill axle.

> An improvement I have seen done to ladder style chains is to purchase
> additional cross chains (normally sold for repair purposes), and double up the
> number of cross chains. This gives much more traction, both in the direction
> of wheel travel, and laterally as well.

    This is the best and safest way. Please do not double up tire chains (2 sets
on 1 tire).

> Probably the biggest mistake that people make with chains is driving too
> fast. If conditions are slippery enough that you really need chains on your
> 4x4 , then 30 mph is TOO FAST. I seldom travel over 15-20 when the rig is
> chained, whether on the road or the trail. Higher speeds will also wear your
> chains at a geometrerically faster rate. Mark  Whatley
>

    I couldn't have said it better myself :-)

--
Trey in Alaska, TLCA #6733
Modified '71 FJ40 :) "My Calendar Girl" (MISS AUGUST 2000!!)
Cruis'n: http://home.gci.net/~trey










FROM: "Jarhead" 
SUBJECT: Re: Tire Chains
DATE: Fri, 8 Feb 2002 12:14:41 -0600
NEWSGROUPS: rec.autos.4x4

"David & Ann"  wrote in message
news:3C63459A.69CD8A76@mediaone.net...
> I've got a set of tire chains on the rear wheels of my '89 Toyota 4WD
> pickup so I can get up the snow and ice covered hill in my back
> property.
>
> The question is, can I put another set of chains on the front wheels?
> I've had a couple of people tell me that you should never put tire
> chains on the front wheels.  Is that only because of wheel well
> clearance issues or is there some other reason?  I've got 35" mud tires
> and 7" of lift so there are no clearance issues on my truck.
>
> Also, has anybody had any problems running tire chains with a Detroit
> Locker?  When I make tight turns in my driveway, I can hear the inside
> wheel skipping over the chains and I'm worried I might break an axle or
> something.
>
> Thanks.
>
> - David

30 years ago when I taught school on the Jicarilla Apache Reservation, one
of the El Paso Natural Gas guys clued me in on how they ran in the Oil
bearing Shale gumbo in that area.(Grey dirt that turned into Axle grease
after a rain).
 First of all they ran tall,narrow tires and when needed they ran front
chains ONLY. Also, they added extra heavy cross chains between the regular
cross chains and left them loose so that the chains would clean themselves
as they rotated. Rubber Bungee tensioners were used by some. Others had an
extra set of wheels with the chains permanently mounted and put on tight
before the tire was fully inflated. ( The cross chains were still loose).
Most of the Jicarilla had 2WD PU's with the latter arrangement.
 When they were confronted with a real narrow place that mandated that they
kept it in a straight line he said to grab a few clicks of emergency brake.
This shifted enough power to the front so as to drag the rear straight
behind the front wheels. This worked on my '69 Scout and later with my HD
Half 1100 Series IH PU. This kept me from certain disaster several times.
 Never heard of anyone having trouble with the chains damaging anything
underneath the trucks. None of them had lift kits either.
--
Jarhead










FROM: Roger Brown 
SUBJECT: Re: Tire Chains
DATE: Fri, 08 Feb 2002 19:38:54 GMT
ORGANIZATION: http://4crawler.cruiserpages.com/index.shtml
NEWSGROUPS: rec.autos.4x4

David & Ann wrote:
> 
> Thanks, everyone, for the advice/experience.  I'm only running with the chains
> on the snow covered trails (and my driveway when I turn the truck around).  I
> wouldn't be able to get up my hill without them.  So far, I've been able to
> climb the hill with just the rear chains, but the snow isn't very deep yet.  I
> may need to add another set of chains to the front if we get more snow.  I'll
> make sure to check the brake lines for clearance first.

Airing the tires down can help, too.  I find that running around 18-20
psi does wonders for snow and ice traction and you can still do freeway
speeds if needed.

http://www.scc-chain.com/products.htm

If you have any question, remark, comment, want to share some philosophy or just want to express your opinion about these pages, feel free to send email to: w.j.markerink @ a1.nl