Birmingham carnival was a massive event in the 60s. It started sometime in the previous century and had grown to the point that they had concerts with big names in a lot of the city centre venues for around a fortnight. The parade was massive and ran from the university all the way through the city centre. Then they built the Queensway. The parade was limited to a couple of circuits around Great Charles street and the annual magazine became a rag mag sold for a couple of bob on the streets. The bed race sounds like a standard rag week stunt but it could have been earlier. Central library do have a run of the magazines from the carnival going back a long time but after it became a rag mag they stopped listing events.