Combines Axle loads for 2366

12 psi all the time, or just when it's muddyIJ Do you road your machine for long distances with the head onIJ

We would prefer to run at 12 all the time. All land is within 2 miles ( I realize that could change in the future) so no long distances will be travelled. Also, the grain tank is always empty when we're on the road, combine has heavy duty planetaries so top road speed is only 16 mph. I beleive any set up we run in the field at 5 mph with the big top full of grain, will easily support the combine empty at 16 mph with or without the head. We have been given rough estimates of a front axle load of 33000 lbs. From my research, 4 Michelin XM 108 ( 650_65R42) will support the load at 10 psi at 5 mph, but I cannot be sure until I know an exact axle weight.

Our 1680 with an 853A row head weighs 13380 lbs on the rt side, 14000 lbs on the left (empty). With 210 bushels of wheat, about 19050 lbs on the rt and 19670 lbs on the left. You could maybe subtract 4000 lbs for the smaller machineIJ That would put the front axle at about 35000 lbs. I would use that number until I weighed it for sure. For cyclic loading on that tire Michelin recommends 14 psi. Dual 710's would be legal down to about 10 psi!

Just take into account that one wide tire would do much less soil compaction than dual tire configuration.

I'm not sure I can agree with that. If the single tire and the dual tires are running at the same air pressure, I think the duals would likely have a bit of advantage on deep compaction. I think the radial tire combination that can run at the lowest pressure is the best for compaction, regardless of how many tires are involved. Just my opinion!

I appreciate the comment on the single wheels, however I would have to agree with farmkid2 on this one. I also beleive we can acheive lower tire pressures with a dual set up than a large single (dual 650_65R42's vs. single 1050_50R32) I would also agree that the duals may have an advantage over the single for avoiding deep compaction, which is one of our main concerns with axle loads greater than 30000 lbs. We also no till all of our soybeans into the corn stalks, so we appreciate the fact that the duals will still straddle the corn rows. We feel we get better soil warming early in the spring with the stalks standing rather than trampled flat on the ground. We were also hoping we could save our 42" rim centers and just weld on an wider rim, where as with large singles we would starting from scratch. I guess trading could be a possibility with a large tire_rim dealer. Also, because the combine has duals now it has the axle extentions, which would put singles on 160" centers, unless we get an offset rim. What about stubble damage on a wide single running over a rowIJIJ Anyone have experience with thisIJIJ All comments are welcome!!

Thanks for the info and for the link. I was getting my info from the Michelin Farm tire handbook which only gave the specs for single wheels. I realize they give a lower load carrying capacity when used as duals. The problem with the 710_70R42's is that it limits our ability to track between the corn rows.( minimum dual spacing of 35.9 inches) Question for you... the charts start the ratings for cyclic loading at 14 psi but give a full listing down to 6 psi if you operate at 5 mph. They recomend a max speed of 6mph for cyclic loading. If we combine at 4 mph in 200bu corn, could we not meet the 5 mph specs when we are fully loaded and meet the 20 mph specs when emptyIJ What's your opinion, whats the differenceIJIJ

We have two machines with large singles. Both have the axle extensions and truss rod like you have for the duals. The rims are centered. We need the large singles because we fight mud that will stick between the duals. We have some milo, and use stalk stompers to avoid tire damage. However, I suspect that would be less effective with corn stalks.

I only know of one machine running dual 710's and it is a 1680. As far as I know, they have not had any problems, but the stress on the final drives and rims has to be a concern. I suppose they run over two rows, maybe 4 rowsIJ Yes, it's the derating of the duals over the single tire that is killing you on load rating. As for cyclic loading, Michelin used to allow the tire pressure to go all the way down. They stopped that in more recent years. I suspect the fear is that a loaded machine will pull into a ditch to unload and roll the tire off the beadIJ Also, there is a lot of torque put on the tire when a person cranks the wheel and stomps on the brake to turn. We are running the 1050's at 14.5 psi and you would swear they are flat to look at them when the machine is loaded. I have experimented as low as 12 psi when the ground is too muddy and we dump at 1_2 a bin. I am not sure you can tell the difference between 12 and 14 psi, except on paper. However, when we run the row head, I think we use about 17 psi. The weight of the long, heavy header really adds up on the front axle. We run 28l26's at 6 psi on the rear, but there is no reason to in the field. Not enough weight to need more than 23.1-26's. However, at 6 psi if you pull the header off they look way too low. We have to add air for highway trips without the header. I have pictures of this stuff if you want to post your e-mail addressIJ Where are you locatedIJ