I've been using my yonex Nanospeed 800 for arnd 3years alr.. How do I know whether I should change a new racquet/whether my racquet is spoilt? For now it seems still ok for use. Thanks!
All new Yonex racquets have a built in smash indicator on the racquet shaft. It is normally invisible. After around 50,000 smashes the indicator still slowly turn yellow, and will turn red around 100,000 smashes. Then it will be dangerous to use as the racquet could explode with every smash! Until you see the indicators, keep playing with the racquet!
Oh yeah, the smash/explosion threshold was too low on the earlier models and there were many complaints... glad they fix that. Maybe they can extend to 1M smashes. Too bad our arms might not be able to keep up 1M smashes. The yellow indicator in my arm is showing, so my arm could explode at any time...