Regarding my front knocking noise

Hi, Still trying to work out what my knocking noise is the front of the bike.
There is no play on the front wheel and I have changed the front pads.
It appears to have a leaking suspension, so have got some new seals and have it booked in with a mechanic on Friday. The one question that I have is where is the speedo drive located? It does not seem to come from the front wheel, the bike is a non abs model.
The mechanic said he will check it over on Friday while the front is in bits. The only thing left could be the bearings, but they seem OK.

The speedo pick up is on the belt side next to rear wheel.

Thanks Wingmann, Well it's not that then. I have just ordered a front barring set just in case, other than that I will see what happens once the suspension is done and the new barrings are in. I can't think of anything else.