|
| Jim is correct in his analysis -- even a 6 psi tire does some damage, but it is relatively minor compared to 20 psi or whatever. The balloon analogy is a good one.
As for tracks, they are inherently inferior to tires -- it took me awhile to figure this out. The biggest problem with most tractor track systems is they only have 2 tracks, so the machine rocks onto the rear of the track under load. Because the load varies, it is nearly impossible to get the tractor ballasted so the weight is spread across the entire track. Again, note that only a slight shift in load/torque will cause it to rock foreward or back. The only design that avoids this is the independently moveable 4-track system on tractors.
Another problem with tracks is there is far less opportunity for the track to flex to conform to soil undulations. Worse, there is no cushion of a flexible casing and 'giant air bag' to absorb the shock of the lug as it first contacts the soil. In other words, the soil can push against a tire lug and deform the casing slightly to absorb shock, but the soil is on the losing end if it must push against a grouser that has a steel idler behind it. | |
|
Compaction and PSI of Tires
