If this is sand you find crossing an arroyo or in an eroded part of a jeep trail, this is a normal desert obstacle you just deal with. Power through and if you can't, dab and walk it out. You don't need a fat bike unless you are going into the dunes or something. But expecting a 1.5 in tire to cope with it feels kind of willful
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Genesis 49:16-17
"Well, well!" said Holmes, impatiently. "A good cyclist does not need a high road. The moor is intersected with paths and the moon is at the full."