mystery hardtail frame
 

Cross posted this over in the mountain bike forum, but this seems sufficiently old or unique enough that that the folks over here might now what it is. Frame is aluminum, serial number is 2KBBW02826.
https://cimg7.ibsrv.net/gimg/bikefor...bb157f0d79.jpg
https://cimg8.ibsrv.net/gimg/bikefor...c7652f3af4.jpg
https://cimg1.ibsrv.net/gimg/bikefor...f4a72bbacd.jpg
https://cimg2.ibsrv.net/gimg/bikefor...de8f65e62a.jpg
https://cimg0.ibsrv.net/gimg/bikefor...c7c5373cf0.jpg
https://cimg9.ibsrv.net/gimg/bikefor...b277764340.jpg

That is really cool! I wonder if it's a custom. Hayes brake boss puts it maybe around Y2K? Earlier? But the style seems later. You could ask over on MTBR's equivalent subforum and maybe Pinkbike.

Too bad "Frank the Welder" has dropped off, he might recognize those welds.
Foe sure it's unique!

Can't help you about the frame, but will say that the BB seems to be one of the versions of the Shimano BB-M950. If you don't already know, it's Octalink V1, not be used with V2 cranks.
See the Shimano Tech docs for details as these are different from most Octalink BBs, it is actually adjustable and serviceable.

2000 Schwinn Homegrown. 2001 Homegrown had disc mounts on the seat stay. Earlier frames had no disc mounts.