I'm imagining a scenario where there is a conflict between humans and intelligent octopuses. The humans' main mode of transport is the bicycle.
The octopuses decide to stage a night raid whereby they will steal the humans' bicycles and dispose of them at the bottom of the sea. The problem is that they must transport the bikes from land to the coast. Dragging these would make a noise so the octopus plan to ride the bikes.
Assuming that the intelligent octopuses are of a size to reach the pedals and the handlebars, could an octopus actually ride a bicycle - even in theory? What aspects of biology could prevent it.
Assume that the octopuses can survive out of water for the time required. (real-life octopuses do sometimes travel short distances on land)
Assume that the octopuses have worked out a way to mount the bikes but they can't support their full body weight clear of the ground on their tentacles for any length of time - hence needing to use the saddle.