Originally posted by tFUnK
i was thinking cannondale but did they have internal cable routes? and also many of their bikes had the headshok system in the 90's.
I don't think Cannondale did internal cable routing on their frames. I didn't see any internal cables on the mystery bike. It seems to have all top-routed cables. Also of worthy note is the roller at the base of the seattube to accomodate the down-pull front derailleur. This type of arrangement really only existed for a couple of years when the combination of top-routed cables and the lack of top-pull front derailleurs were the norm... and those years were between 1990-1992. Shimano started coming out with top-pull front derailleurs around 1993 to provide bike manufacturers with cleaner cable routing.
And I think the Headshok system only started becoming available on the higher-end models sometime around late 92 or 93. While this bike has a DeoreXT rear derailleur, it looks like it may not have been top-of-the-line. The brakes look like DeoreDX rather than DeoreXT (mixed group commonly found on the one-step below top bikes).
The straddle cable and holder looks to be of the thinner variety leading me to believe the components and possibly the bike date closer to 1990 or 1991. Later Shimano cantilever brakes (ca. 1992+) started coming with thicker cables and a round straddle holder rather than the "thong-wedgie" one you see here.
The most indicative portion of the bike that leads me to date it to pre-1992 is the bottom bracket which looks to be of the older non-cartridge bearing type. I believe Shimano went to cartridge bearing BBs (at least for anything above Exage) in 1992.
I also notice a slightly raised front end (assuming this isn't an optical illusion) as compared with what was (I'm assuming) supposed to be a horizontal top-tube which leads me further to believe that this bike was retrofitted with an aftermarket suspension fork that was pre-threadless. That also narrows down the years some although I know many fork manufacturers offered threaded and non-threaded versions for quite some time throughout the 1990s.
While I can't be 100% certain, the large aluminum tubes combined with big fat welds and the "dating" of the bicycle via its components to around the very early 1990s strongly points to it being a Cannondale.