Give you AR bike are massive upgrade in acceleration and turning agility with this machined alloy flywheel.
 
The Stock Flywheel is steel and weighs in at 331grams
 
The alloy flywheel weighs just 117grams. 
 
Other benefits include much better jump landing and overall improved handling in all conditions due to a lighter rear end. The slow speed stability is not affected at all with this upgrade, you get the best of both worlds.