Even with two 70lb sandbags in the back I was having a tough time keeping up with cars.  Anything over 25mph and it would get real squirly.  I had the 235's aired down to 30 psi (the max psi is 42 maybe I should be going lower than 30?).  

Something closer to 23psi would be better.

I'll have to try dropping the pressure and see how it goes.  Some of it is just getting used to the type of vehicle.  I played around a little today and notice that when it starts to slide if you let off the gas you slide more.  Seems like when it starts sliding if you give it a little more gas the front tires start pulling more and pulls the back end inline.  Almost lfeels like a rally car with the rear end sliding around the corners but the front pulling you in the right direction.  Lots of fun.  Around town I like 4wd low since I am 30mph or under and it gives me more gear ratios to choose from.   Anyone know of a prefabbed winch mount for the sidekick? 

your tire pressure is WAAAAY to high ... 30 would be like rolling on concrete tires.
try 18 psi ... 22 when not on slick stuff.

Even with two 70lb sandbags in the back I was having a tough time keeping up with cars.  Anything over 25mph and it would get real squirly.

There is something wrong with your truck, probably the alignment. Sidekicks are very stable vehicles I have driven lil Suzy in all sorts of winter weather including ice storms since 1991. She handles very well in bad weather. I do agree that that 4wd is important.

I had the 235's aired down to 30 psi (the max psi is 42 maybe I should be going lower than 30?).

Snow and ice is not mud and rocks. on slippery surfaces the way to think of traction is PSI "pounds per square inch" This is not the air in the tire, its the pressure between the tread and the surface. In bad weather I would run those tires at max PSI to minimise the contact pad.

On dry pavement you want to find the pressure where the tread rides evenly across the surface. This can only be done on new tires because if the tire is run over or underinflated the excess pressure on the center or outside of the tread will wear away first and the life and performance of the tire will be reduced. Tires are checked like this. Find a place with smooth pavement and a long straight run where you can test your pressure. get some white chalk and put lines across the tread. Drive straight until some to the chalk is worn off. if it is gone in the center lower the pressure, outside raise it. Of course the alignment must be completely within spec for this to work.  

In bad weather I would run those tires at max PSI to minimise the contact pad.

Are you trying to kill somebody? You're really suggesting that he fills his tires to 42psi?
Great if you want to do that, but I would never suggest that to anyone. The last thing you want is a hard tire on ice, thats why winter/ice tires are made of softer rubber. Keep them at the recommended psi(23-26psi) and be careful. a rwd vehicle doesn't act the same as a fwd car, so don't try to keep up if you're not comfortable. My rig isn't great is the snow/ice/slush either, but it's better with 10psi than 23psi

It did seem better when I had dropped originally from 35-30psi so I think I will continue to drop the psi and test it where there is no traffic.  I now remember watching a show on some trucks in the arctic and they all deflated the tires to almost nothing.  Just enough so that the bead didn't let loose.  I am sure there is a sweet spot I just have to find.  It does alright on fresh snow but snow/slush where other drivers have criss-crossed over making trails is where it jumps back and forth. 

I think there are a couple of other factors on the snow driving.  I haven't looked for a pump yet but this doesn't feel like it has power steering.  I could be wrong or maybe its just a week power steering but you do "feel" the road through the steering wheel.  And the steering doesn't have any slop and is quite quick.  Add that to a short wheel base and a top heavy vehicle and you have to have a light touch on the wheel. I can let go of the wheel while going over railroad tracks, ect. and the steering wheel will bump steer back and forth 1/8th of a turn.  Its kinda comical like a four wheeler or go cart. 

Are you trying to kill somebody?

NO

You're really suggesting that he fills his tires to 42psi?

I am not suggesting anything, I am stating absolutely that on slick surfaces the smaller the contact area the more traction you are going to have. It is basic physics.

The last thing you want is a hard tire on ice, thats why winter/ice tires are made of softer rubber.

Air pressure and rubber compound are two completely different things. All though you are right a softer compound is better for traction under all circumstances, it has nothing to do with air pressure and you are wrong snow tires are not made out of softer rubber as a general rule.

My rig isn't great is the snow/ice/slush either, but it's better with 10psi than 23psi

In snow/slush with your tires underinflated the vehicle will be riding on the outsides of the tread. As your traveling down the road instead of the tire cutting through the snow, the center of the tread is going to be pushed up by the snow and the vehicle is going to ride on top of the snow instead of the pavement. This is extremely dangerous. I encourage you to do some research about this so you can make better choices in the future.

After enough google searching it looks like for slushy snow you should have your normal max psi with the shorter contact patch to cut through the snow.  If its fresh deep snow where few vehicles have gone then low psi would be better to dig through and float. 

If its fresh deep snow where few vehicles have gone then low psi would be better to dig through and float. 

I am not sure how much, if any, benefit could be gained by doing this. Again you have the problem of tread cupping so instead of the tire pushing the snow out the sides of the tread an underinflated tire would push some of the snow to the center of the tread, I don't see this as being beneficial. Then you have the handling problems created by underinflated tires, not to mention the increased possibility of loosing a bead if you were to get the vehicle sideways. I was born and raised in Michigan where most people know how to drive on snow and never once in my 53 years on this planet have I heard of anyone deflating their tires to drive in snow, virgin or otherwise. I have also driven in my share of fresh snow and I have never had a problem driving in snow with fully inflated tires.

I am not suggesting anything, I am stating absolutely that on slick surfaces the smaller the contact area the more traction you are going to have. It is basic physics.

ok, I waited, and no one has said anything ...
this is complete crap.

you put 500 pounds on 1sq inch versus 500 pounds on 100sq inches ... it's the same "force"

The statement "the smaller the contact area the more traction you are going to have" is complete bullshiat.
If you're talking about digging down to asphault, then a bicycle tire will get there right away (and it has a very small contact patch). Guess what, people don't run bicycle tires for a reason.

Frictional force has MUCH more todo than contact patch and anyone who understands "physics" would get this.

sidekicksrock, you need to do a little more research on tire pressure. The next time it snows go drive around with your normal psi then lower your tire psi to 10psi and see how it handles. My Sammy with 32" Swampers at just 15 to 18psi will not go anywhere easy. I lower the psi to 5psi or less and that thing will go anywhere.


spyder0069, as was mentioned have your alignment checked and lower you tire psi to around 20psi and see how it handles. And yes AT tires are not the best choice for a snow tire. My Sammy has Swampers on it and it goes great in the snow but as soon as it is slick it does get squirrelly, but then the locker does not help. The '95 4dr Kick I have does great in the snow but it is stock with studded snow tires.

I now have the tires at 25psi to try out and then will try 20psi. Tomorrow I pick up my steel tube to fix the rusted out stock one as mentioned in the earlier post.  The local steel place said they go by the outside measurement on the closest they had was 1 5/8 which is 1.625" whcih should slide nicely into my my original tube which measured about 1.7" ID.  The 3ft long piece is costing me $55 though which seemed kinda high.  It was like $12 a foot and then the rest was the fee to cut it and taxes.

you put 500 pounds on 1sq inch versus 500 pounds on 100sq inches ... it's the same "force"
[/quote]

500lbs on 1sq inch = 500 lbs per sq inch

500lbs on 100sq in = 5 lbs per sq inch.

BIG DIFFERENCE

The reason we air down our rigs is one to get a larger contact area and two to decrease the tread psi contact.  When you driving in a soft material (sand, mud, snow) a lower tread psi will allow you to stay on top of what every you are driving on.  If you ever driven on sand and have played with air pressure you will know what I'm talking about.

So, if your driving in the snow and the snow is really deep, maby airing down your tires and flloating on top is what you need to do.

But, the most comon approch is to have fully inflated tires so that you have the most tread psi.  That will help you dig throw the snow and get down to where the traction is.  Also, the thinner the tire the better for tracting psi.  This is one reason why a 2wd truck will go through the snow better than a cammaro with wide tires.

you put 500 pounds on 1sq inch versus 500 pounds on 100sq inches ... it's the same "force"

This has already been addressed so I will not comment.

The statement "the smaller the contact area the more traction you are going to have" is complete bullshiat.

You throw out the word "Frictional Force" but based on your arguments you do not seem to understand what it is.

Frictional force has MUCH more todo than contact patch and anyone who understands "physics" would get this.

This is bizarre, Frictional Force is what we are talking about. On ice, 1,000 lbs of weight concentrated on a small contact patch will provide more traction than the same weight spread across a larger contact patch when all other factors are equal.

 There are a number of factors that contribute to tire traction on ice, rubber compound, tread design, etc. all affect traction and the pounds per square inch of force between tire and the surface is part of the equation as well.

sidekicksrock, you need to do a little more research on tire pressure. The next time it snows go drive around with your normal psi then lower your tire psi to 10psi and see how it handles. My Sammy with 32" Swampers at just 15 to 18psi will not go anywhere easy.

A 32 inch tire (what 10.50, 11.50?) is a huge tire to run on a vehicle as light as a Samurai in the winter. You don't specify what surface you are talking about when you say "I lower the psi to 5psi or less and that thing will go anywhere" It has already been discussed that the off road trucks in Greenland run big wide flotation tires at very low tire pressures. This is of course because they want the trucks to stay on top of the snow, and the way to do that is to increase the size of the contact area between the tire and snow, which decreases the PSI between the surfaces. If this is what you are doing then you are right. However as I stated above a tire at 5 psi is not going to be safe at hwy speeds, and we are talking about snow now not ice.

If I was in a situation where the snow was to deep to drive through I would not hesitate to lower the air pressure in the tires and try to stay on top of the snow. However there can be a downside which is when you stop you are likely to sink into the snow and end up high centered on a mound of snow.