Bias to radial--is re alighning nessesary?

Interesting look at tire contact patch loads:



The radial patch leads a bit reducing trail.
Hoop

 

Aww man!---getting to technical for me LOL

 

I've done probably two thousand cars that exact way on the front end rack and never had an issue with toe it.

Spinning the tire and scribing the line around the tread (usually in the center) eliminates the problem of runout in the tire or rim throwing the measurement off.

Yes a car should have the alignment checked when it gets a new set of tires but a guy should read his tires on a regular basis and watch for unusual wear patterns too. Run your fingers over the tread and if they feel feathered to the inside you have too much toe in and if they are feathered to the outside it's toed out. Excess camber is going to wear the edge of the tire that the excess camber is on as the weight of the tire is riding on that part of the tread.

One last thing, don't get caught up in using the specs that some of the magazine articles show for rods or trucks that are set up to run the Streetkana or Gymkana type events at the rod trots unless that is all your rig is going to do. They usually call for extreme negative camber that will eat a pair of front tires in a couple thousand miles or less on the street.

 

I would have it checked just because of the price of tires and making sure everything is good, probably $60 well spent.

 

Yeah really!

We're not dealing with Watkins Glen cars here.

 

I never re-aligned just for that. However, I once mounted bias-plies on a car whose ch***is underpinnings were getting a little sloppy. The Bias-plies helped keep the vehicle tending to drive in a straight line. This was a front-drive vehicle. I never yet tried it on a conventional

 

The only question about this procedure is that when measuring the rear of the tire you can't get the measuring stick up to the center of the tire even with the spindle,so if you are measuring---say 5" up from the floor and say you have 1/16" difference there ---wouldn't it be more if you were measuring in line with the spindle?

 

Use a square or a nut on a string or similar to drop a line from the back of the tire straight down to the measure.

 

Short answer: You may need an alignment but not because you bought new tires.

However, if you did buy new tires, and need an alignment, now is the time to get it because a bum front end can wear out new tires fast.

 

Great point ! Screw it !

 

Well for what its worth---here is a picture of the tires I took off the front---they both wore the same way,on the pic the left is the outside of the tire,both wore more on inside,but if you rub your hand from left to right,the 1st tread is wore lower than the 2nd one----soooo what do I need done? Will a toe-in correct this? and since the alignment shops don't know diddly about these types of suspensions,what degree should I tell them to set the toe at?
Thanks

 

That's too much negative camber and too low air pressure. Maybe a touch of too much toe out, can't tell from the pic if it is feathered.

Hoop

 

the only place they are feathered is between the 1st 2 treads on the outside,but a while back I noticed the feathering and got it aligned---I think that stopped that. Those tires have almost 15,000 miles on them from what I been told --that ain't too bad for front bias?

 

Definitely need a few more PSI.

 

I was running 32 in them----have 36 in the new radials