What is the actual Outside Diameter of your shaft, If you don't have verniers to measure it you can wrap a strip of paper(non stretch) around the shaft , mark it where it overlaps (it will be about 90mm) ,divide that number by pi (3.14) and you will have the exact diameter.
If you don't want a soft or rough tennis racket grip and want to keep the same hard shiny finish you can wrap some lightly wet-out Fibreglass around it , then wrap it tight with electrical tape ,and leave it to cure. if you want a smoother finish you can sand it and finish coat it with some waxed resin
Lats