VY Storm Front-end knocking noise

[gordo881005]

Going home last night doing about 100kmh, and i heard what sounded like a 4 stroke sitting next 2 me. loud but deep knocking noise, i slowed down and it stopped, its only happened once or twice in the last few weeks, my mate reckons its got something to do a 'bush' in the front, as he kicked the front tyres, and you could see them shudder back and forth slightly, any ideas on which "BUSH" i would be need ing to replace?

[chargedvx6]

Caster rod to k frame bushes. Could also be a wheel bearing which is common in VYs

[gordo881005]

Cheers, i'm getting it looked at Thursday, me mate mentioned something about a 'castor rod', but i got no idea, so i'll leave it to the pro's.