OK, trying again, as I posted in another thread to get to the "magic 10" number.
1983 Schwinn Sidewinder frame in blue
"FU" doesn't register in the Schwinn serial number databases.
Head tube with color-coordinated Chicago badge and serial number
Seat cluster showing classic forged Schwinn construction and 0.833 seatpost
Unique cable stop placement
Forged Schwinn chainstays and one-piece bottom bracket shell
Heavy-duty dropouts forged to the frame
No other decals, but it still has the original dealer sticker
Weighing in at a svelte 15.0 lbs for frame, fork, headset, seat post, seat clamp, stem, and BB cups. Must be the bottom bracket cups that add all that weight.