Hi,i'm new to this forum and just last week i bought me a SBIKE 506 from 1991.It was my first mtb ever,also in '91.He's equipped with LX (full) 21 speed.Allready some upgrades planned:8 speed cassette and XT STI,Rigida Ultimate rims (polished) with Sachs hubs and IRC Mythos Slick tires,other...