I am setting up my first SS with horizontal dropouts. I am using a tugnut and am finding a little hop in the rear while coasting at higher speed. It is likely happening a little while pedaling but I am not noticing. The chain is fairly snug, could I be too tight or too loose and thus causing the rear to have some unwanted movement?

Keep in mind that this adjustment ride was made on pavement and I would likely not notice it on some singletrack downhills because I would be so happy to be riding my first steel bike since I had a banana seat and sissy bar which was back in 19...well a while ago.