NSF HEAVY suspension clonk/knock

[dr_jekyll]

Had this exact problem myself a while ago. replaced a gone pbush and was still there and coildnt figure it out. Turned out to be my engine moving under load. Was on solid mounts and couldnt move it with a bar in there yet when i booted it 'BANG'. turned out to be a mix of the craddle had collapsed underneath and lower fork was moving on the actually fork bush (lower mount was powerflex). Think this movment was just swing the box about under load creating the noise