This is how it would feel like if you were the "monkey" (old nickname for a sidecar passenger) on KillaJoule.
You can see the sidecar suspension working to the right in the picture, it is really neat. The sidecar suspension, as well as the front and rear suspension, is designed by my dad Sven Håkansson.
The noise you hear is mostly from the chain, which is also quite neat. You can't hear the chain on an internal combustion motorcycle, the engine is way too noisy.