new to the forum, just started riding to work on a daily basis. Situation- when i shift gears there seems to be a lag between the input and the actual shift. I will attempt to shift while pedaling and nothing, then click and clank it jumps into gear. I have had to shift, stop pedaling, and start pedaling again to not get the jarring shift. I am assuming the cable is stretched but am not sure. I ride on the road which is flat, it is an older GF wahoo (2005 ish). Looking for some advice, am familiar with tools and would rather learn to fix than pay to fix. Thanks...........