If it helps, here's a 1993 model that I've converted over to a heavy road tourer.



Crank, wheels, derailleurs are original.

It's a very nice riding bike and I can see where it'd be a real nice ride on the trails, should you want to keep it to it's original intent. From what I've learned, Bianchi had five different mtb models that year, all named after an endangered species. The Nyala was second from the bottom, and very well made as were all the Japanese-made Bianchi's of that era.