Loose sand? Loose sand with rocks, loose over hard, loose with roots; that's the stuff of all my rides out here in So Cal. In back, I like the WTB Weirwolf race 2.1. Enough bite to not spin in sand, but not a heavy slow tire like the Nevegal (which I have used). Up front, I prefer a wider tire to help float over the sand. Been using a WTB Wolverine 2.2 and find it a good performer. The Nevegal 2.1 up front wanders less in sand, but feels slow and heavy by comparison so it's a trade off. Next I plan to try the WTB Weirwolf race 2.3 up front. A bit heavier than the Wolverine and a bit wider than the rear tire. I had the Weirwolf 2.1 up front for a time, and it worked well for all but cornering, where it was a bit skittish. It is also narrower than the Nevegal (real width, not number on sidewall) so I am thinking that the 2.3 might do better. If only the Nevegal did not feel so heavy and slow... mine is gathering dust in the garage.
Tzvia- rollin' slow...
Specialized Ruby Expert/mens Bontrager Inform RXL
Specialized SWorks Safire/mens Bontrager Inform RL
Giant Anthem-W XT-XTR/mens Bontrager Inform RXL
Fuji Newest 3 commuter/mens Bontrager Inform RL
Novara E.T.A commuter/mens Bontrager Inform RL