You can add it to your ticket in person (i.e. in the ticket office) if there are spaces on the train. Not sure if it can be done online though.
They are quite strict with bikes around the Dynamo time so I wouldn't risk jumping on!
I had booked to go down the night before, I.e Friday but realised I have things to do Saturday morning so have rebooked it to go down on Saturday afternoon. Really appreciate the comment though as there was only 1 time left that suited my needs and had bike space!
You can add it to your ticket in person (i.e. in the ticket office) if there are spaces on the train. Not sure if it can be done online though.
They are quite strict with bikes around the Dynamo time so I wouldn't risk jumping on!