Chalk test for tire pressure

[JohnBoyToo]

In a not so subtle attempt to get my post count up !!!
How many of you have done the chalk test to get the perfect contact patch for YOUR truck, YOUR tires and YOUR vehicle weight ?

Take a piece of chalk. mark a line across each tire, edge to edge, drive forward about 3 or 4 tire revolutions then stop slowly without turning.
look at the chalk line,
if the center is gone, but you see chalk on the edges of the tire, too much air.
If the center is there but the edge is gone, not enough air.

Keep repeating, add or take out air as needed, until you have even wear, on the chalk across the tread. Works on cars trucks, trailers, lawn tractors, you will be impressed with how much longer tires last, when they have the right wear pattern.

Road Racers will do this to ensure the biggest contact patch to the ground so they can corner best....

so I've heard

 

[towcat]

doesn't work on trucks that run on either extreme.....empty and bouncing off the cracks in the concrete or loaded past max GVW......ie. towtrucks

 

[JohnBoyToo]

thanks for assisting me in getting the ole' post count up
***************

let's limit the use to those "legal" vehicles then! :Sly

works for most "normal" cases - and used by most autocross people I run into as well - and some of them are extreme

 

[holtzer1]

consider how much turning you do though...every time you turn even 1 inch past perfectly straight..caster will have your tire wearing on the edges. the best tire pressure for anyones truck is whats placed on the tire placard on the door. tires not inflated properly could blow out under load causing more problems than a little tire wear.

 

[Freightrain]

Never heard that way before. Most patch tests go by leaving a black mark and seeing how much is there. Only edges...not enough air, only center..too much air.

The way to really confirm is wear pattern on tire. If center wears...too much air, edges...too little air.

I run mine slightly under pressure only to get a better ride. Since I don't haul alot of weight to speak of...I don't worry about overheating sidewall.

 

[bsays]

Cool idea, I need to get my post count up to.

 

[Ggg]

I have done the chalk trick many times on many different vehicles. It has worked well for me.

 

[holtzer1]

i just keep them aired up to what the vehicle man. recommends and ROTATE them every 6000 miles and keep the alignment in spec. tire rotation is more often neglected causing wear problems more than any other service supposed to be done on a vehicle.

 

[Roland_Jenkins]

Never tried the chalk test. I have left two narrow long patches of rubber on the street before but didn't bother going back to see if the contact was even or not.

Seriously, I just put dedicated snow tires on my truck. Les Schwab tires, soft rubber, sipped and studded. They put 55 # which I thought was under inflated. Max is 80#
So I aired em up to 65 front and 60 rear. Tires didn't work very well on the ice and snow so now I'm back down to 55 front and 50 rear. Teats on the outside edge are still there . . . .

For the most part, a big post count just means you have nothing to say about a lot of things

 

[soulpatchfr]

i've been using the chalk method of tire inflation for years & i swear by it.
of course, i never use OE tires as replacements & thus never go by the door sticker...