The Arashi Nitrogen Charged Rear Shock is a good improvement 
 
if you are looking reduce nuisances associated with OEM shocks
 
 
Features：
 
Nitrogen charged；Monotube design；Hard anodized
 
Low-friction piston rod & eyelets
 
Built-in adjustable preload on all applications
 
Precision CNC-machined components
 
Multiple spring rates available to accommodate a wide range of riders
 
Multiple selections of bearing sizes to fit more street & vintage bike
 
Each shock set of 330mm and 360mm includes 10, 12, 14mm bushings to fit all street & vintage bikes.