2001 520sx front to back, here are the changes and what i noticed. 1. 20" front wheel with buchannan spokes and 739 dunlop----more stable in slippery turns and more confidence all around. 2. factory 48mm forks with titanium-nitrite coating and external preload adjusters valved and resprung with 44 springs-----no bottoming and very firm fluid motion through out. 3. factory r&d black anodized 16mm offset clamps------had to do it to fit new forks. sold my emig 18mm. didnt notice any steering changes. factory r&d comes with really cheap bolts. had to replace them. 4. azonic yamaha bend bars-------i dont really like crossbarless bars. 5. oberg sports throttle barrell with bearing-----smoother and less fragile. 6. enduro eng. clutch lever with bearing and steel line-----more durable line, but no noticable change in lever pull. 7. big gun exhaust------more noise, less weight and doesnt look stupid like stock silencer. no real noticable change in power. 8. works connection skid plate------echoed to much gear noise so i took it back off and dont use any now. 9. gripper seat cover------stock one molded underneight and didnt grip well. 10. 15/54 gearing with longer chain-----geared it down for mx and make the bike longer to handle better. i think this worked. 11. talon rear hub with buchanan spokes-----had slightly messed up oem hub with loose sprocket bolts. 12. factory shock with high and low speed compression damping and pds 4 spring------------just feels way better everywhere on the track. maybe some of it is just in my head, but hey whatever works. 13. ebc mxs brake pads------the best period. big difference. must say mxs. 14. black rear fender------looks better to me. 15. orange acerbis flag hand guards-------helps with roost. mounts fairly easy and doesnt get in your way at all. 16. thats all i can think of with out the bike in front of me to look at.