55 mph on a new bike... big mistake did not check rims for tru before riding. I nearly bit it, bike shook like I have never seen, only thing that saved me was my choices, lay it down in the street, in the ditch full of rip-rap or squeeze my legs tight together while pumping the brakes. I haven't crossed 50 since. I have been up to 43 on our tandem, very understanding wife!!!