Handlebar oscillation

[Snorty]

Is it normal for my handlebars to oscillate when I take both hands off the bars? Starts off slow and gets more violent the longer my hands are off. I don't ride without my hands usually I was just having a look.

[pinkyfloyd]

Single word answer...

No!

Longer answer. Check wheel bearings and orwheel ballance.
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Teflon-Mike:I think I agree with just about all Pinky has said.

[MarJay]

No, the bike should be stable without any rider input. What sort of bike is it? Have you got the right tyre pressures? Are your tyres worn or 'cupped'? Are your head bearings OK?

It could be a lot of things, but it shouldn't really happen unless you're on an MZ and doing 80mph...
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Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[doggone]

There's a nice gentle downhill with mild curves I like to ride with no hands for fun when no one's looking - doesn't do anything like that but certain road surfaces might start it off so try it in more than one place maybe ?

[Skudd]

Do you have a top box or luggage.

Without luggage my bike is a stable as a rock, put a top box on and the bars waggle.
Tyres can effect things too, both pressure and tread depth.
Bar end weights
wheel balancing etc.
My main one though is the luggage.
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[robocog]

Had this on the GPZ and what cured it for me...

Accurate rear wheel alignment (using axle stands and string rather than judging by eye or relying on the markers on the swing arm)

Picture attached (hopefully)

Put bike on center stand or use a rear paddock stand

Get a long (thin) piece of string or fishing wire- long enough to wrap at least 3 times round you bike lengthwise

Find the center and loop it round your rear tyre at the back and attach the two ends to a pair of axle stands or anything that will support the string nice and tight and at a good height (about 1/2 way would be ideal but often stuff like axles/forks/fairings get in the way so just as high as possible)

Now pop the bike in gear so the rear wheel doesn't move/spin, put the steering pointing as straight ahead as possible

Now pull one side nice and tight and get it so that its just kissing the forward part of the rear tyre's sidewall
(make sure the string does not sit in any sidewall notches/cuts if your tryres have them - this method possibly wouldn't work with knobblies!)

Set the axle stand or whatever your using to hold the string nice and taught and at a good height and make sure the only bits the string is touching on your bike is the front and rear of your rear tyre

Do the same the other side

Now with the steering held central it should be obvious by eye
Or by measuring at the distances the string is away from the forward and rear of the front tyre wall both sides...they should be the same

if its not even both sides- adjust the alignment of the rear wheel (keeping chain tension in check!)

It's amazing how much better my bike seemed to feel once both wheels were pointing the same direction and it no longer shook its head!!

Regards
Rob
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Needs a bigger garage...

[Snorty]

Cheers guys.

There doesn't seem to be any play in the bearings at the front.

I will adjust the alignment and see if that helps, will check the tyre pressures too.

Does anybody know what they should be on a GPZ 500 as I don't have my manual to hand and I can't remember.

[robocog]

2nd Gen with 17's at both ends..
PSI: 32 front 36 rear
Bar: 2.25 front and 2.5 rear

Regards
Rob
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Needs a bigger garage...

[hellbound]

My GN250 would do this as soon as the tyre pressure dropped below 30psi

so check tyre pressures on the front


and why are you riding with no hands?...thats illegal that is....
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[Nixon]

Check:

chain and sprocket condition
chain alignment
wheel alignment
rear wheel bearings
sprocket carrier bearings
Rear monoshock linkage bearing
headstock bearings
bars are actually bolted tight (important one)
forks set to similar settings
even fork oil levels
fork seals
front wheel bearings
front brake disk(s)
front brake calipers
bar end weights
steering damper (may need one if not fitted)

Could be any if not all of these things as a place to start

[Aka Matt]

Nixons list seems like a good place to start. I had this issue with my bandit where by the handlebars would start to slowly oscillate when I would take my hands off the bars and become more violent with each oscillation. Turned out that the headstock bearings were shot in my case.
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Current bike(s): 2016 Tuono 1100 Factory, 1998 Hornet 600
Previous: 1998 YZF600R Thundercat, 2001 Bandit 600, 2002 GSX-R 600 K2, 2011 Tuono R, 2013 Z1000SX

[Tarmacsurfer]

I've always worked on the basis if it doesn't do it unless you take your hands off the bars then there's a simple solution
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[Ben_m]

What tyres are you using? I noticed this after I got a pair of Avon's. Took my hands off the bars on a section of road that I have done this before and at about 40mph the wobble was quite violent. I had everything checked by a yamaha dealer and a local independant garage and nothing was found. I came across something on the internet that said not all Avon tyres were perfectly round (on a forum I think). I swapped for a pair of contis and problem solved!
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Yamaha Fazer FZS600 2003 ¦ Peugeot 206 GTI 180BHP 2003 ¦ BMW 323i SE