Talking about tires

[PeteV]

Hello everyone,
wondering if anyone could tell me if mounting a 9.5x24 Ag tire on a 9x24 rim instead of a 7x24 rim makes enough of a difference to mess up the 4wd ratio??. I am trying to figure out what kind of an effect a wider or narrower wheel has on the same tire. The weird thing is that firestone recommends a 10 inch rim for this tire, my Yanmar manual says to use a 7x24 rim and I have 9x24.(this is a spare set of tires, tractor currently has turfs on it). The only thing that I can see is that the sidewalls might be bulging a little more or less, but I can't see it making any difference in the circumference(and thus the 4wd ratio)Any thought and comments are greatly appreciated.
thanks Pete

 

[Anonymous Poster]

Generally, you will not make big mistake using wider rims, because width of rim doesn't affect so much to rolling circumference of tyre. Small difference of rolling circumference, as result of wider rim, will not affect to the ratio, because similar situation occurs when you put load on 3 pt. hitch, and rear tires "lay".
For your tyre dimension, recommended is 7" wide rim (allowed 8"), according to Continental catalogue. 9" wide rim is anticipated for 11.2" tyre. But, if you mout your tyres on 9" rims, it will look more flat on top, but wider on the rim then on top.
Problem can occur in mud, because lugs are narower than tyre "baloon", tyres will swim in mud and you will have less traction. /forums/images/graemlins/frown.gif

For example, my smaller tractor has 8.3/8-20 tyres on 5.5" rims, 12.4-28 on 11" rims, bigger one has 360/70-20 tyres on 11" rims and 420/70-30 on 12" wide rims (recommended rims are13", but can be 12-14") , and didn't feel any problem. Both tractors are 4WD, of course. /forums/images/graemlins/grin.gif