Currently I am plannign a number of bike packing trips to Sumatra and North Vietnam with my Giant TCR advanced. I will be riding through rather steep mountainous terrain, not always very good roads and the possibility of getting caught in the rain while descending is always there. My dilemma is wether the ultegra 6800 rim brakes would do the job or should I invest and go for disk brakes. Does anyone have experience in similar terrain with rim brakes? I would appreciate any advice regarding this matter.