When I first started using it I felt it in my neck, then it seemed to go away. It does not take much extra weight cause a problem. It's like wearing a coal miner's helmet on the bike. They are great lights and people can really see me coming which is important in the traffic around here. No biggie. I'll just put it on the bike. According to my research the bar diameter on my Cannondale Super Six is 31.8 mm so I ordered a metro bracket that goes from 24-35mm. That should do it. I hope.