Head Shake

[dna]

Oh enlightened ones, I have a question: My Sprint '03 ST has a nasty little headshake with the bars vibrating side to side quite a bit at 45 - 70 mph if i take my hands off the bars. This is new - I routinely rode miles with out ever needing to touch them in the past.

Thinking tire issue first, I replaced the front tire (the Avon was cupping pretty bad). Still shaking.
Thinking Tire out of balance, I had the new tire re-balanced at a shop. It was fine. Still shaking, possible worse.

Is there any other obvious place to look? Brakes, bearing, springs? I am quite uninformed about all things suspension related. The bike is 3 years old with 30K miles. I had the fork oil changed at about 25K.

I start a 30 hour rally Sat Am, so I'm hoping there is something I can check, adjust and tighten up, as there is not time to order parts.

Thanks,
-Dna

[nortoncharlie]

Steering head bearings getting loose or notched will do this. Front wheel bearings if they are very bad, I would tell you to check rear wheel alignment, but that could be tricky with the single sided swingarm.

[Pcdabbler]

Certain brands of tyres can cause this, slowing down, hands off, worst at around 45. Quite a lot of different Bikes can suffer from this. Most people ignore it, Just don't take your hands off the bars !

And the Azaros are well known for it

[ This message was edited by: Pcdabbler on 2007-05-24 16:51 ]