Recently I purchased a set o Avid 7 V-brakes for my internal geared hub cross country bicycle. Now I need to buy the set of levers for the V-brakes and I am facing some dificulties in my choice. The LBS presented me 2 choices: either AD3 levers or SD7 modulation levers. AD3 levers, I could see they are simple levers as I used for many years like Tektro levers. Now what I do not know is how SD7 levers work and what are the advantages over AD3 levers or the advantages for my type of ride. Please guys, help me understand these diferences.