No way you can string that racket to 25-26lbs. It will deform for sure. I've strung that kind of racket at maximum 20 lbs but on the racket's owner risk. I recommend maximum 17-18 lbs Sent from my iPhone using Tapatalk
An intermediate/advanced player using a Basic racket? Why the change? (I mean, you can find Yonex rackets capable of being strung at higher tensions.)