Newbie here and mostly ride on flat roads, but just started to climb some hills. I was told that the best place to put your hands on a descent is on the "drops". BUt my fingers are too short to grab the brake levers. A guy I was riding with today said that I could buy shims to adjust the brake levers so that they get closer to my fingers. Can anyone tell me what these are called and are they usually readily available at bike shops? On-line sources? Thanks in advance for any input!