How long have you been playing with the Radical?
Three years. Before this I played with a HEAD racket but I was using the Instinct. The old Instinct had a wider frame and it was a little bit more powerful. My racket now has a bit more control. I played with Babolat for a while but I came back to HEAD. I feel most comfortable with HEAD rackets.
At 6ft 11in, do you use a longer frame?
No, it’s a regular size. But the handle is a bit bigger. There is no number for my grip size – it was made especially for me. It’s huge. If there was a number I guess it is eight or nine.
How much have you experimented with your rackets in the past?
Not a lot in the past few years. I haven’t done any new stuff because I like it how it is and I haven't had a lot of injuries so I don’t want to change anything.
Compared with the rackets you played with when you started your career, have they changed very much?
Not really. For me, the only change was when I changed model from the Instinct to the Radical. I don’t know if they are any different from the rackets from the 90s.
How many rackets do you take with you on court?
Usually four or five.
What strings do you play with?
I play with Luxilon in the main and in the crosses I have natural gut. My rackets are strung at either 25kg or 24kg depending on conditions.
You don’t use a vibration dampener?
When I was younger I played with a vibration dampener but not any more. A lot of guys use one but it’s not for me.
Do you remember your first tennis racket?
It was a wooden racket – it was very heavy. After that I remember my dad bought me a Puma racket like Boris Becker was playing with – when I was little I really liked Becker so my dad bought one for me. It was a white racket with red. It was a used racket but I loved it like it was new. I still have it.
Do you keep many of your old rackets?
Mostly yes. I don’t have the one I hit the fastest serve with [in March 2011 Karlovic broke the world record for the fastest recorded serve – 156mph] because I had many rackets in my bag so I don’t know which one it was but I still have that collection of rackets. I give some rackets away to charity.
When did you last smash a racket?
Years ago. When I was younger I did it a lot more but I don’t think I have smashed any in the last five years. It is always satisfying when you smash a racket but I don’t do it anymore. It isn’t the racket’s fault – now I realise that – so I don’t crack them. ￼