I just bought a 2008 SE Stout 29er singlespeed frame to build up a mountain bike with. I have been riding a singlespeed road bike for several weeks now. It is 48T in the front and 16T in the rear. This ratio gives me no problem on roads with moderate hills, so that being a measure of my ability what is a good gearing for me to purchase for a 29 inch singlespeed mountain bike that WILL be used for trails?