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What causes a speed wobble (high speed weave)


Bike is super light. Too much pressure don't allowed the carcass to heat up enough. Front psi should raise about 3 psi and rear 6 psi. If you did a bit of chemistry you know the volume doesn't change, you can measure the pressure... +3F/+6R is about what you need to get the proper temps. Too much psi make the tire patch smaller too... less rubber on the ground.

My hot psi run F33/R35-6. I can ride the speed limiter all day long...
 
30/30 of what? Again your silly Gandalf units no one sane can comprehend? Like 30 puddings per square feet? Damn you all.
 
marthy said:
Bike is super light. Too much pressure don't allowed the carcass to heat up enough. Front psi should raise about 3 psi and rear 6 psi. If you did a bit of chemistry you know the volume doesn't change, you can measure the pressure... +3F/+6R is about what you need to get the proper temps. Too much psi make the tire patch smaller too... less rubber on the ground.

My hot psi run F33/R35-6. I can ride the speed limiter all day long...
Click to expand...

Thanks. Was just wondering.
 
Relz, hope you get it sorted soon, I have no ideas what would work for your bike
I have now done 1200 miles on the BT023's, and the speed wobble is getting better as the tyres wear, I can now get to about 115 mph before it starts!
Oh, and tyres still look like new, still have bobbles on the front tyre!
 
Now i haven't read all this thread but for tyres to work you need suspension that can cope with a variety of conditions and it is always a compromise,road and track but if all you boys are on standard suspension to me that is it.
I weigh 65 klios and the suspension is to soft no matter what tyres you use or what you weigh.
I have been struggling with head shake from day 1 and my bike has done 300 miles from new
 
marthy said:
Throw your owner manual in the trash and drop those presssure to 30/30 before you hurt yourself. Those are the pressure I would use on a 500 lbs bike riding 2 up... and still.
Click to expand...
That sounds a bit low to me, but I'll give it a go tomorrow. I'm currently located near my private airstrip, so I can easily reach speeds of 200 kmh quite safely.

Mind you, I was running 42/36 with my previous tyre setup (Dunlop 214 on front), with no problems whatsoever. But its an easy test, so why not.
 
marthy said:
Bike is super light. Too much pressure don't allowed the carcass to heat up enough. Front psi should raise about 3 psi and rear 6 psi. If you did a bit of chemistry you know the volume doesn't change, you can measure the pressure... +3F/+6R is about what you need to get the proper temps. Too much psi make the tire patch smaller too... less rubber on the ground.

My hot psi run F33/R35-6. I can ride the speed limiter all day long...
Click to expand...
BTW the manufacturer wrote 42/36 cold psi
 
l34chy said:
Now i haven't read all this thread but for tyres to work you need suspension that can cope with a variety of conditions and it is always a compromise,road and track but if all you boys are on standard suspension to me that is it.
I weigh 65 klios and the suspension is to soft no matter what tyres you use or what you weigh.
I have been struggling with head shake from day 1 and my bike has done 300 miles from new
Click to expand...
65kg??? are you 12 years old? :)
 
l34chy said:
I wish i was gone are them days :)
but what i'm getting at if its to soft for me and it tank slaps out of corners and shakes it's head at 120 plus it's not tyres it's shit suspension.
MT jealousy will get you no were:)
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tis true............ive almost replaced all my clothes for 1 size larger now..........nature is cruel to the elderly. im 84kg or 89kg after a few rounds of sugar laden thai beer and the bike does the same to me....:(
 
MT account said:
tis true............ive almost replaced all my clothes for 1 size larger now..........nature is cruel to the elderly. im 84kg or 89kg after a few rounds of sugar laden thai beer and the bike does the same to me....:(
Click to expand...

What can i say MT some of us are lucky middle aged beer swilling slobs i just don't seem to change no matter what;)
still these bikes are good but the suspension is it's down fall or should i say shit it's nothing to do with tyres or wheel alignment.
That's my opinion only.
i'm sure there is plenty of life left in this subject no matter how much beer is supped:o
 
l34chy said:
What can i say MT some of us are lucky middle aged beer swilling slobs i just don't seem to change no matter what;)
still these bikes are good but the suspension is it's down fall or should i say shit it's nothing to do with tyres or wheel alignment.
That's my opinion only.
i'm sure there is plenty of life left in this subject no matter how much beer is supped:o
Click to expand...
Cheers to that! [emoji6]
663629c6406a8fa57820c91457f126d1.jpg
 
l34chy said:
What can i say MT some of us are lucky middle aged beer swilling slobs i just don't seem to change no matter what;)
still these bikes are good but the suspension is it's down fall or should i say shit it's nothing to do with tyres or wheel alignment.
That's my opinion only.
i'm sure there is plenty of life left in this subject no matter how much beer is supped:o
Click to expand...
you wait till you hit 50...........i was ok for a year n then POW! the weight just keeps on coming.......worse things happen at sea as they say...........:rolleyes:
20140817_231007.webp
 
makfai said:
The first thing I can suggest is you go back to basics and decide if you are experiencing wobble or weave.
Then look at what causes whatever your symptoms are.
There are three basic areas: bike; environment; rider. All are variables which need to be considered.
For example,
the same bike can perform badly for one rider and well for another rider simply because of the different weight of the riders!
Installing accessories e.g panniers and/or top-boxes can affect handling.
Different road surfaces can affect handling.
Unfortunately, it is a methodical process of elimination - as you have already found! :(

As you have been doing, you have to check the bike is set up right: wheels balanced; correct tyres & pressures; rear wheel adjusters set correctly; wheels aligned correctly etc so you can rule out the basic set-up. Then take a critical look at your accessories/mods to see if they could be having an effect. Finally, consider if you as the rider could be contributing to the problem - may need to eat more pies!

Good luck and let us know how you go on. Have you heard from others with the same probs?
Click to expand...

Those were interesting videos, I've actually seen them in the past but have forgotten about them.

I'm definitely suffering from high speed weave, not low speed wobble.

I tend to blame the tires the most, as my weight, riding position, and accessories have not changed (perhaps I put on weight, which should help avoid this issue [emoji4]).

I did install a new front tyre, which goes against the guy in the video's recommendation, but my rear is relatively new, and looks great IMO (4000km on a sport touring tyre).

Assuming that a newer rounder front tyre can emphasize weave, as mentioned in the video, perhaps I'll try to run the recommended high pressure on the rear and a lower than recommended pressure on the front to kind of 'square it off' until it wears down a bit.

Or even better (but more of a pain) I could install a new rear, to match my new front, and keep my 4000km used rear tyre for my next change, at which point the front won't be so new anymore.
 
What's your suspension setup? Stock? If you are on stock suspension, I had my front end drop 10mm to add some front bias. You could try 5, 8mm maybe and see the difference.

I remember on my FZ6R I did had instability at higher speed all loaded... adding rear preload help calm things down a lot. If you're rear rider sag is within 35-38mm might not be a bad idea to drop the front a bit at the time.

I have the ZX10 rear shock (8mm longer) and the front end is back to "zero" now.
 
For what it's worth, I've found the bike to be very stable at high speed.
Did you notice the weave before you fitted the new front tyre?
 
marthy said:
What's your suspension setup? Stock? If you are on stock suspension, I had my front end drop 10mm to add some front bias. You could try 5, 8mm maybe and see the difference.

I remember on my FZ6R I did had instability at higher speed all loaded... adding rear preload help calm things down a lot. If you're rear rider sag is within 35-38mm might not be a bad idea to drop the front a bit at the time.

I have the ZX10 rear shock (8mm longer) and the front end is back to "zero" now.
Click to expand...
My suspension is already cranked up to max preload and close to max rebound.
I've also dropped the triple by about 10mm to aid turn-in speed.

Again, my suspension settings haven't changed recently. They are the same as before I installed my new front tyre, and there was no weave then.
 
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