FZR600 '89 Wobble?

[Jenks]

Hey all,

Right bit of a weird one with my FZR.

Basically i was out on the private runway, and i took her upto 100.

once you reach 100 ++ It starts wobbeling / shakeing... not tank slapper type, just kinda of swaying, And it gets worse and worse untill it nearly does tank slap..

What could cause this!?
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1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Timmeh]

worn swingarm pivot, wheel bearings or steering head would cause what you describe.

Or it could be something really simple like the back wheel not being lined up properly.
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GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[bish777]

Check tyre pressures and their condition, check your steering stem nut is torqued to the correct spec, all the spindles are done up tightly then start checking all your various bearings.
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GSXR1100J

[Jenks]

Right, thanks for the help i will get onto checking these.

As far as i know the bearings are fine, as it was only just moted (July - and wobbeled then)

Advisory was that the headrace bearings were a little tight - but this was because of not being use.

How do i check alignment?
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Timmeh]

A way to check wheel alignment is to use a really long straight rule. Line it up with the back wheel and see if the front is parallel. You can also use a piece of string tied to the back wheel if you like.
____________________
GSXR400 x2 | '94 RVF400 | '93 TZR125 4DL (again)
20:22:30 BLUEX5: i would love to be forced to undergo a**l plugging with different sizes
20:48:18 Temeluchus: comp you hunk of smouldering homos3x you

[Kickstart]

Hi

You haven't dropped the yolks down the forks have you?

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[TUG]

i had a slight wobble due to the bar ends not being in evenly, check that too, it makes a difference.
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Haz ER-5, innit!

[Jenks]

nope yolks are the same, Ill check the bar ends right now too see them!

anything else?
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Vincent]

I'd suspect head race bearings, they wear out eventualy. What tyres have you got?

[Jenks]

tyres are bt45s i think, I know headrace were an advisory on the mot - Because they were a little tight (Was stored)
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Vincent]

Aye HRBs can make a big difference, i swapped mine over recently from ball race bearings to taper rollers and the handling was transformed. Done any before

[Jenks]

nope, only just really got it!
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Vincent]

What year/model is the bike the bearings, (if it turns out you need some), aren't too pricey but it can sometimes be a bit of a bitch to remove the old ones.

[bish777]

incorrectly torqued steering nut will cause weaving, get it torqued up properly. My FJ1200 was horrid over 100mp until i got the steering stem nut torqued properly.
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GSXR1100J

[Kickstart]

Hi

Don't think the BT45 is available in an appropriate size for the FZR600. Presume you have used a 150/70 tyre, which will have lifted the back end up 15mm or so, an quickened the steering.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Jenks]

not sure then! bike isnt stored here, its at my mums!!

its a 140/60/zr18
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Kickstart]

[Vincent]

[Vincent]

Afforementioned K2;

https://i77.photobucket.com/albums/j71/Drewskovitch/Scan2.jpg

[TUG]

sorry to hear about that, i tell everyone who owns fzrs to keep to the stated tyres, even on a thin 140 i got my knee down, my friend has an over size on his cbr, best get him to check this post
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Haz ER-5, innit!

[Jenks]

Tyres = Dunlop Sportmax Radial.

Rear = 140/60/zr/18
front = 110/70/zr/17

When i was out today i tested not holding on so hard, it it DID calm it ALOT!!!!!
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[TUG]

lol, so you where wobbling on it?
____________________
Haz ER-5, innit!

[Jenks]

the wobble wasnt as potent, but it was still there, But hardly noticeable!
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Kickstart]

Hi

They should be fine, although they are not particularly good tyres (I know, I have them, although with a 150/60 rear, on my FZR600) and will be old tyres.

To be honest I have not found the FZR nervous at all (and mine has done over 50K now, on the original shock as far as I know). Pretty stable as stock.

I would say go round having a good check over everything. Steering head bearings, wheel bearings, fork seals / bushes (and if you find a supplier for both top and bottom bushes then let me know!), etc.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Jenks]

would it be best to get a 4" rim?
____________________
1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi