Tire size conversion

[PHPaul]

I did a short search and didn't see an applicable thread, so sorry if this has been asked a million times before...

It's time to shell out for a couple of new tires for my ancient Pasquali tractor.

Old tires are marked as 6.50-16. They're R1/Ag tires.

I can find 6x16 or 7x16 fairly easily, 6.50 not so much.

So, couple questions:

1. I'm assuming the rim is 6.5" wide. I'm also guessing I could go up to a 7 or down to a 6 without issues. Yes/No/Maybe?

2. It's 4 wheel drive, so ideally all tires should be the same size. Are there likely to be height/diameter differences if I go up or down a half-inch on the width?

I'd rather not spring for 4 new tires right now. I'll put the new ones on the back (don't use 4wd that much) and the two best old ones on the front.

 

[CincyFlyer]

If all of the tires are the same size now, then yes, you'd need to keep them all the same. With staggered sizes (all of today's 4WD tractors) you'd need to keep the size ratio the same. (There is now a US standard for tire size ratios.)
If your tires are ancient (my old garden tractor certainly is) and the sidewall exhibit deep cracking, it may be wisest to replace all four. At the least, measure the bolt pattern and offset, and see what other wheels may fit; sometimes you can pick up used wheel assemblies for peanuts.

 

[oldnslo]

Found this site that shows conversions for older tire sizes. You have to scroll down to the older tires though.
Tractor Tire Conversion Chart

 

[LouNY]

As I recall the old Pasquali tractors used equal sized tires all around. If you can't swing 4 new ones as far as going two at a time.
I would carefully check and look for clearance issues front and rear especially at full lock steering to decide if I could go up to 7x16's
or if it's necessary to go down to 6x16's after finding out the OD of the new tires as well as the width. If the new ones you end up with are
taller then your old ones I would put the taller tire on the front axle that way when 4wd is used the front will lead the rears which will result
in much better results then having the fronts being pushed by the rears. You could even get lucky and lowering the air pressure in the taller
tires resulting in the same or very close loaded radius which is what determines the actual tire balance.
Good luck

 

[PHPaul]

Hit my favorite tire place and 6.50x16 is about as common as hen's teeth, so I bit the bullet and ordered up 4 of the 7.00x16 so they'll match.

Clearance is not an issue as it's an articulated tractor and the whole tractor turns, not just the tires.

Put an awful dent in the toy budget tho...:shocked:

 

[oldnslo]

.

Put an awful dent in the toy budget tho...:shocked:

Gonna play you gotta play ;-)

Yes tires have really gotten expensive.

 

[PHPaul]

Gonna play you gotta play ;-)

Yes tires have really gotten expensive.

Especially for a tractor that gets used about once a month for half an hour...