My rear wheel seems to have a hop (it took me a while to identify, I think, what is happening). The brakes grab in the rear only as well. Cruzbike dealer checked and adjusted the brakes, but a friend watched me riding and said the wheel was doing something funny. Last night I spun it and believe I am seeing the wheel hop and it is not just a characteristic of the bike and braking system. Has anyone else experienced this? I have emailed Cruzbike support but really need to get this dialed in right away. As always, ideas and suggestions welcomed.