have you checked, if the stem is ok with carbon steerer?
You momentarily terrified me because I remember reading that the Thomson X4 wasn't recommended for carbon steerers at one stage. Fortunately the Thomson X4 FAQ (http://bikethomson.com/stems/elite-x4-31-8-mountain/) says:
*Q – Is X4 safe for carbon fiber?
A – X4 is engineered to work very well with both carbon handlebars and carbon steerer tubes. All torque requirements in our instructions must be strictly followed for carbon components. Our carbon bars work nicely with X4! *
You momentarily terrified me because I remember reading that the Thomson X4 wasn't recommended for carbon steerers at one stage. Fortunately the Thomson X4 FAQ (http://bikethomson.com/stems/elite-x4-31-8-mountain/) says:
*Q – Is X4 safe for carbon fiber?
A – X4 is engineered to work very well with both carbon handlebars and carbon steerer tubes. All torque requirements in our instructions must be strictly followed for carbon components. Our carbon bars work nicely with X4! *
Phew!