I'm trying to figure out if I'm going to need any Whatchamacollars for
my Big Dummy. Are the racks normally just slipped inside the frame's
tubing, and the Watchamacollar clamps that junction? Does that mean I
would need 4 of them to make the rear rack solid and not let rain and salty road-spray in?
Is there something else that would work? $35 for what looks like a pair of seatpost clamps is pretty pricey.