I have 3 options 1) XTR short-cage deraileur + LX shifter - $100 2) 9spd XT deraileur + LX shifter + SRAM 7.0 cassette - $60 3) single speed What do you guys think of the above two deraileurs for trials(oviously), I dont think I would be using the cassette. The real question; Single speed, once the cassette is off (where a cass. tool is needed) All I need is a handfull of spacers and a cog, right? Wouldnt this put much stress on the hub? Do I need any special tools for this? Where do I get these spacers? One more thing; will a 9spd deraileur work fine with an 8 gear cassette? Thanks'