A buddy of mine just got one. this was the famous banshee that rolled down the Glen Burn in Shamokin, P.A.
they do look good but it has a little to much bling for me.
I had a set of them and i was led to believe it was the joints and yours could be bad but look at the holes on the frame where the arms are mounted too. mine were oval and it gave the impression the ball joints were bad. i welded washers to the frame for the fix.
Not my auction ,
http://cgi.ebay.com/ebaymotors/BANSHEE-FULLBORE-FULL-BORE-REAR-PLASTICS-FENDERS-WHITE-_W0QQcmdZViewItemQQhashZitem1c12052a36QQitemZ120561412662QQptZMotorsQ5fATVQ5fPartsQ5fAccessories
F.A.S.T sells them springs. http://www.farmandsandtoys.com/products.asp?make=YAMAHA&model=BANSHEE&offset=10&cat=CARBS/%20INTAKES I have a set and was able to tell a difference.