R4's are good for certain things.
but will take my AG's / R1's if had a choice.
it is the "unknown" sudden muddy patch. that R4's will begin to spin and slide. vs R1's that will keep on digging in and rutting but will pull themselves right on through. been up axle deep and keep on going. while R4's would of had me stuck.
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tire tread is a big factor. had to put new tires on the 555C TLB due to one tire dry rotted and cracked out the side wall a good portion of it. tread difference between new and old. i would say old had 70% tread left. it was a completely different machine with new rear tires on it. granted i still got myself stuck, and had to break out the FEL and backhoe to get my rear up to better ground. but to slight mud patches to wet grass were i use to slip the tires or simply slide side ways on a hill i would not with the new rear tires.
if i had R1's on the rear of the 555c TLB. there would be no doubt i would keep on going. BUT! the problem with the 555c TLB. is it is so heavy, and doing a lot of dirt work. just having R1's on rear. i would be doing more time spending clean up ruts than actual working the tractor. vs the R4's that yes do rut, but the ruts are so wide and not as deep that it is fairly easy to clean up the ruts.
on the old allis chalmers CA tractor i do have AGs / R1's on it and it is primarly only does finishing mowing. yes R1's can and do tear up the yard, when i make a sudden sharp turn. *coughs some* i like doing tight 360 donuts spins around trees in high gear while mowing. and if it just rained in last day or so. you can really see the tire impressions in the yard. and perhaps even a chunk of sod ripped up. if i was on a heavier tractor things would be worse for sure. but *shrugs*. just do not think R1's will tear up yard as soon as you roll them on to the yard. any tire will, including R4's will tear up the yard, and if it is to wet it is just plain to wet and muddy to drive anything on the yard. and you will need to just wait another day perhaps 2 to drive on yard without tearing things up, when doing anything major that involves more weight. from logging to moving dirt to other.
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chains due make a large difference. and so does 4wd. so does an experienced operator more so operator use to the machine. prefer to have differential lock, and left/right rear steering brakes on opposite foot than the gas / go / hst pedal. 4wd is not always what it is cracked up to be.
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ply rating. personally prefer a higher ply rating. granted higher ply rating means a much rougher ride. i do not remember the specifics of various ply ratings. and why's and why nots for this or that. but it was worth spending extra cash towards higher ply rating for me. i think a bigger thing for me was dealing with thorns, and higher ply rating meant thicker rubber of the tires. and in that less chance of a leak due to a thorn or nail or something else. and higher ply rating meant more weight capacity for the tires?
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i truly hate skidding logs with chains wrapped around the log. i have torn up costly chains, and destroyed my yard, and had to re-attach chains, and re adjust were tractor was multi times to get chains unhooked from around logs. and still waiting to come across. "forgets there name" see attached image
View attachment 278935 just a single chain between 3pt hitch draw bar, and this thing what ever it is called.
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old gear manual transmission type might be more beneficial more so if it has a creeper gear for log skidding.