I have no idea other than some market anomaly where not enough sold. In 1999, my son bought an 830 aluminum as his first mountain bike. '99 was the only year for the alu. 830 as well. There is nothing wrong with the frame and it's still going strong. He used and abused it and moved on to FS bikes; it has now been 'handed down' to me and is my XC racer.
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Originally Posted by Mark Twain
"Don't argue with stupid people; they will drag you down to their level and then beat you with experience."