Originally Posted by topspin247
It was strung with Kirschbaum Proline 2 (17g) and tension 57. It was strung by a pro shop in Daytona Beach, FL.
Kirsch PLII 17 has a stiffness index of 236 which is fairly soft for a co-poly string (range = 187-350), and at 57lbs (max tension recomm by Kirsch) the SBS would be around (**approx
**) 63lbs if strung properly. We have strung hundreds of Prince SP frames and not seen this problem but a few times where customers are a bit rough on frames (anger issues). This is not the case from what you have stated.
Racquets can also crack when strung high with poly or kevlar when the ball is shanked alot near the key spots (points in the frame where the main and cross grommets are very close. Manufacturers will look for imperfections in material or manufacturer errors when replacing frames, outside of that it's on you.
Pro players go through approx 80 to 140 frames a year due to racquet stress (stringing everyday along with practice and matches) and fatigue. If your son plays everyday you may want to look into multiple frames of 3-4 to reduce stress fatigue. If this continues to happen with SP frames you may want to look at another racquet company. Good luck.