Hyperpro Progressive Rear Spring / F850GS, F850GSA

This Yacugar/Hyperpro two stage progressive rear shock spring fits the stock rear shock (both ESA and manual), and is ideal for riders with a wide load range. 

The stock spring rate is 150 N/mm. This aftermarket spring starts at 155 N/mm (which is very close to the stock spring rate) and when that stage of the spring coil binds it becomes a 210 N/mm spring. Your spring preload setting will affect how soon the spring transitions into its stiffer rate so this can be very helpful for standard weight loads that transition into very heavy loads such as riding solo and with a passenger. 

A spring compressor and basic shock know-how is required to change the spring. Otherwise it is designed as a direct replacement for the stock spring.