My dynamo wheel has a Shutter Precision SP PV-8 hub. The wires simply insert into two holes on the outside of the hub, and I think Shimano hubs have a similar set up. The connection is not very secure, and the wires can pull out easily or get wet. The wires also tend to fray and get twisted out of shape when you have to remove the hub and reconnect them.

Is there a fitting that I could put on the ends of the wires to get a more secure connection, or another way to prevent the wires from fraying and twisting?