The cantilevered drop outs were introduced in 1990 and by 1991 none of the range had u-brakes. That looks like a 1990 Red Shred to me, with the exception of the colour of course :?
I agree with Adrian...1990 SM Red Shred...but looks like it may have had a replacement frame as that colour was not a standard option. It was the colour of the M2000 of that year though.
The paintjob on your frame is "Blue to Silver fade", specific for the 1990 SM2000, the c'dale top of line (before they created the Omega during the summer of 1990). The SM2000 only used a top level frameset with the first generation pepperoni. So yours is not an SM2000 : it's the Beast of the East frame with the higher BB and the sloping geometry. It's a 1990 frame because you got the cantilevered dropouts (they didn't exist in 1989) and you still got Ubrakes (which desapeared in the1991 catalog). But it's a "Competition Series" with its Ritchey forks. When I see the steerer tube, it's a 22".