I am running 15/42 gearing on a stage 2 with some head work.

 

Have you ever tried the 14-40? what do like better for the sand? Were you able to find a 42T Steel Gear

 

I did try the 14/40 but it was not as good in the sand as the 15/42. I got an alum. sprocket for the rear and it has held up just fine for 2 years so far. The 14 front also puts a lot of stress on the chain as well.