Has anyone else had trouble with the rear coaster brakes on their bikes? Bean Oil (Chris) & I both had our rear brakes lock-up on our saturday ride at the beach... His rear wheel skidded to a stop, & my pedals locked and started turning & threw me a little into the air!, I landed on my butt on the seat and started dragging my feet like Fred Flintstone to stop!!! We are both currently buying new rear wheels, & I am having a front wheel built with a old drum brake in it. (I think a drum is the best way to go with a springer fork.) If anyone has a bike with a rear coaster brake, I would advise that you have a front brake too!! Any thoughts?