I have bought a replacement headset for my 2012 Fire Mountain. I bought this one FSA No.10 Internal Headset | Chain Reaction Cycles It looks exactly the same as my old one but it seems to be a real pain to install. My LBS took off the old one while doing another job for me so I don't know how easy/hard it was to get out the old one. The new cups don't seem to fit even though they are the same size. I had assumed I didn't need any special tool to fit such a headset. Has anyone any experience with TH No. 10 FSA headsets?