I've got a Colnago 3.0 CLX which comes with Shimano Ultegra brake levers but Colnago callipers. There's just no way that they stop anywhere nearly as well as the 105's on my Specialised. Living on Dartmoor, there's a lot of need for good brakes on the downhills and it's really spoiling the descents.
I've had them adjusted and tuned but whilst better they are still no match. Could it be the rims on the wheels or am I better off getting Ultegra callipers and in fact the latest Ultegra 6800's, or should I stick with the wheels & callipers and change the brake blocks - any thoughts?