This is the english version of how to extend the cork handle of a rod, the butt section. It may sound like a rather complicated procedure, but it doesn't have to be.
What you need is; a cheap carbon tele-pole rod to cut a piece from, which will be the new core. You also need cork rings, epoxy glue, a saw and sandpaper.
Step 1: To be able to fit the new core part that you cut off from the carbon tele-pole you need to pry off the butt in the end or saw it off depending of which alternative is possible. I did this on my Strike Pro Hamer and I was able to remove the plug which was glued on.
Step 2: Grab your carbon tele-pole that you bought and find a section that fits in your rod. Stick it in as far as it goes and make a mark to see how far you should glue. Also mark where you should cut it, that is how far you want to extend your rod. Cut it so that it's an inch or two longer than you want it. It's easier to handle it that way. Add the epoxy glue to the part that goes in to the rod, push it in at let it harden.
Step 3: When the glue has dried, fit the cork rings on the extension. If the fit isn't great, add tape to the extension or file off the cork if they are to tight. When the fit is good, glue them together and to the extension. Push them together and let them dry.
Step 4: Saw off the extra inch when everything has dried. As I was able to remove the plug in one piece I was able to glue it back on. Otherwise you will have to create a new one from at champagne cork or something else, if you that buy a real one.
Step 5: Even out the transitions between the cork rings with a fine sandpaper. The finer it is, the longer you will have to be doing it but it will also be better. If there are any bigger holes in the cork you can add de saw dust mixed with glue and smear it on.
After this the rod was ready to use. Eight centimeters longer doesn't sound like much but you don't have to add that much to make a difference in performance and feeling.