I never thought about pole vaulting for distance. Apparnelty it is a Dutch/Frisian sport.

https://en.wikipedia.org/wiki/Fierljeppen

The bicycle would give it interesting dynamics. Much more weight, but one could start with a fair amount of speed.

Perhaps build a pair of poles to attach to the bike like jousting lances. Full speed ahead with the lances in front of the bike. Drop them into the river, and fly!!!