Front Wheel Shimmy

Hi Guys

Not terribly mechanical so just looking for a few pointers... I have a GSX1250FA... last few rides I noticed a pretty wicked shimmy (wobble almost) from the front wheel felt through the handlebars at mid range speed particularly if I'm holding quite lightly eg. maybe one hand off etc...  if I grab tight again seems to be OK.  Have never really noticed it before... any clues as to what it might be?

FS

Could be one of a few things. Most possibly. It has lost it's balance weight. Have a look. Check all your bolts are tight. Should not be steering head bearings . But check for any movement anyway. Front wheel off the ground and push and pull both forks at the same time , feeling for any movement. Also check that front wheel is rotating smoothly. Wheel bearing. Check front tyre. Rub your hand smoothly around the tyre, checking the edges for any scalloping.  Best of luck.

Yep, what Hammy said.  Most likely the front wheel needs to be rebalanced.  But some possibility of either the head stem or front wheel bearing has worn. 

Thanks guys - will have a quick look but I think it'll be a job for the local workshop by the sounds... appreciate your help.

+ 1 to what Hammy suggested.
Weights are usually glued on the flat of the rim and should be easily seen if one has gone missing.

I wouldnt put it past a knackered tyre to do weird things through the bars.

If all the above don't cure it , & the front end proves to be straight & true , although I have never heard of it with the Bandit , some bikes ( my Diversion for example )would get a shimmy up as you describe  if the tyre I used had more of an " O " shape as opposed to an "A" shape profile .

Front tyre worn. 
My experience,  anyway.  
If let go of the bars with both hands, they would start to oscillate slowly getting bigger.  
A new tyre and she rides straight and true.

A few more to add :

Warped/cracked discs,  forks twisted in yokes.

Bosco15 wrote:Front tyre worn. 
My experience,  anyway.  
If let go of the bars with both hands, they would start to oscillate slowly getting bigger.  
A new tyre and she rides straight and true.

Same a few times for me on different bikes.

NZspokes wrote:

Bosco15 wrote:Front tyre worn. 
My experience,  anyway.  
If let go of the bars with both hands, they would start to oscillate slowly getting bigger.  
A new tyre and she rides straight and true.

Same a few times for me on different bikes.

I had the same on my original Dunlop when it was pretty shagged, same again with the PR3 that I changed just before the Parkes trip

Check your tyre pressures. I've just bumped my pressures up to 38 front and 42 rear and it feels a lot more solid. Also you dont have a top box hanging off the back of the bike with a bunch of house  bricks inside do you? As suggested also check tyre wear and suspension settings.

You may want to get your mechanic to string line your rear wheel. Dont trust the marks on the swing arm to ensure your back wheel is straight. Those marks can be out by miles sometimes.

My 2 cents plus GST,
Phil.

lacko wrote:Check your tyre pressures. I've just bumped my pressures up to 38 front and 42 rear and it feels a lot more solid. Also you dont have a top box hanging off the back of the bike with a bunch of house  bricks inside do you? As suggested also check tyre wear and suspension settings.

You may want to get your mechanic to string line your rear wheel. Dont trust the marks on the swing arm to ensure your back wheel is straight. Those marks can be out by miles sometimes.

My 2 cents plus GST,
Phil.

While I generally agree I found my Bandit marks to be pretty damn close. 
You don't need a mechanic to string line the bike and I wouldn't trust that most would do it anyway and if they did it would be by laser. Most would say they had done it but just set the marks.

The marks on my Katana swing arm are out by miles. When I used to get it serviced when I first bought it, I'd explain to the dealer that if they were going to adjust the chain, just do it evenly each side and not line up the marks. Every time they'd line up the marks. I could tell as soon as I rode off. Worth checking.

I'd agree that its not a difficult job if you know what you're doing but the original poster said he wasn't mechanical.

Phil.

lacko wrote:The marks on my Katana swing arm are out by miles. When I used to get it serviced when I first bought it, I'd explain to the dealer that if they were going to adjust the chain, just do it evenly each side and not line up the marks. Every time they'd line up the marks. I could tell as soon as I rode off. Worth checking.

I'd agree that its not a difficult job if you know what you're doing but the original poster said he wasn't mechanical.

Phil.

But the original poster rides a Bandit...........