She likes to shake her head

LotusSevenMan · Post by **LotusSevenMan** » Sat Mar 17, 2007 2:23 pm

does this VTR. It didn't used to so I'll relate the tale.
Noticed an increase in vibration recently after a good ride out and having changed the CCT's I did the logical thing............... Panicked!!!

Can't find a thing wrong with the CCT's so leave alone says I.

A 118 mile ride today and I found (I think) the problem but not the cause or solution. It starts at approx 58-60mph on the overun and down to about 40mph. Fifty is the definitive worst point. This VTR wants to shake her bars from side to side by about 50mm. Hands off it does this very distinctly.
Now, the question is, where to look for the problem. Head races seem OK. I 'favour' the front wheel balance being wrong. Can't see any signs of a balance weight having been thrown but that's not to say the sticky pad didn't go with it. Any other suggestions? The rear shock is set on the four from softest setting. Fronts are, err hidden at the moment under the bar raiser caps but have not been altered from the settings when it was all OK.

Anyone?

Kitch · Post by **Kitch** » Sat Mar 17, 2007 3:13 pm

Could the wheels be slightly out of line? I know the rear chain adjusters are notorious (as on most bikes) for not being accurately aligned.

If they're out a little bit, might only be noticeable with a certain wheelspeed and weight distribution...

Easy to check and eliminate too.

LotusSevenMan · Post by **LotusSevenMan** » Sat Mar 17, 2007 4:40 pm

Kich.
Already checked this with parallel rails etc. All fine there!!!

I really do want to find something if you know what I mean (so I can cure it properly)!!!

A local bike shop mentioned steering head bearings. It doesn't feel 'notchy' but ummmm; could be I suppose.

richard · Post by **richard** » Sat Mar 17, 2007 5:34 pm

hi l7m,

funnily enough...

...had this problem on my zzr1100, its worth you checking an adjusting the headbearings, dont have to be notchy just a bit older and a bit looser, back adjusting nut off and tighten up again - regrease if you can be bothered taking the head apart.

Also, just check you've not got a lazy, dragging caliper on one side - ie strip and grease - sometimes easy to tell if pair of pads on one side worn down more than other side - but that assumes both sides replaced at same time to start with !

Also check no slop / wear on front wheel bearings / spindle clamps tights and axel bolt tight /

any finally - its not had 'slime' added to front tyre has it ???

cheers
rs

LotusSevenMan · Post by **LotusSevenMan** » Sat Mar 17, 2007 7:16 pm

Richard.

Front wheel bearings etc all fine nad no wobble etc.
Interesting one re dragging brake pad. Ummm. I'll have a look at that.
Will have a go at the head bearings I think though. Damn nuisance with no centre stand. Ok with a paddock stand rear and a block of wood and trolley jack under sump?

Definitely no slime stuff added to the front or rear tyres!!!!!!

MrMastodon · Post by **MrMastodon** » Sat Mar 17, 2007 11:22 pm

Had a very similar thing on a TDM850 once - instability at lowish speeds. Hands off and it would wind itself into a tank slapper.

Anyway - turned out to be just worn tyres. I know it sounds too obvious (and I don't know what your tyres are like), but worth considering. And the VTR isn't the most planted of bikes and seems, to me, sensitive to worn tyres.

Anyway, hope this helps and good luck!

LotusSevenMan · Post by **LotusSevenMan** » Sun Mar 18, 2007 12:05 am

Front is fine but the rear is a bit centre flat ish. Like it when I got it so probably needs a change soon anyway. You can feel it is tricky to counter steer from one side to the other as it doesn't flow easliy if you see what I mean. Could the rear alone create this head shake?
Thanks.

Zer0Zer0 · Post by **Zer0Zer0** » Sun Mar 18, 2007 9:49 am

i've got a full set of new bearings.. headrace pair and front and rear wheel bearings...cost me Â£50 yours for Â£30 + postage

Zakalwe · Post by **Zakalwe** » Sun Mar 18, 2007 10:04 am

I had the headstock bearings done on the SP1 recently (there was a slight knock when you applied the front brakes).

I made a hell of a difference when it came back...felt like a new bike. It tracked a whole lot better and just felt so much stable (I found that it tended to drop into corners with the dodgy bearings)

My bet is dodgy bearings..though you could always loosen off the triple clamps a bit and bounce the front end up and down....maybe the forks got twisted when you dropped it a while ago????

LotusSevenMan · Post by **LotusSevenMan** » Sun Mar 18, 2007 10:24 am

Zak.
If the forks twisted by it falling over at zero miles an hour off its sidestand then there really would be a problem!!!!!!!!!!!!!!
Actaully rode it a few times since then with no effects so this problem is 'new' after rides where it was OK.
It certainly might be h/bearing at just coming 21,000 miles. Bet it only ever had the 1 molecule of grease that most of the 'big four' companies ever put in to start with.

Zer0Zer0 YHM

Post by **sirch345** » Sun Mar 18, 2007 12:58 pm

LotusSevenMan wrote: Damn nuisance with no centre stand. Ok with a paddock stand rear and a block of wood and trolley jack under sump?

I just had a thought on that

If it's possible, you could fit the rear wheel of your bike where the front wheel normally fits in the support on the tray of your bike garage, thus holding the bike up right, then use a block of wood and a jack under the sump

LotusSevenMan · Post by **LotusSevenMan** » Sun Mar 18, 2007 2:20 pm

g*d it must be good to have brains!!

Brilliant thought. Hope the rear wheel isn't too fat for the stand, but deffo worth a try!!!

Post by **sirch345** » Sun Mar 18, 2007 3:11 pm

LotusSevenMan wrote: Hope the rear wheel isn't too fat for the stand, but deffo worth a try!!!

That was my only concern

Stratman · Post by **Stratman** » Sun Mar 18, 2007 6:58 pm

If you use a paddock stand at the back and trolley jack under the sump it will fall over!

Put the trolley jack under the offside exhaust pipe where it turns to run parallel with the ground. Before that, put some wood under the sidestand. Jack it up, pull the bike upright again (towards the trolley jack side) and put another bit of wood under the sidestand. Bits of chipboard are fine.

Whilst I wouldn't leave the bike on the trolley jack under the exhaust for any length of time, it works fine.

Actually, to check the head bearings, you can just pull the bike up and back using the sidestand as a pivot and the front will come up off the ground.

Mine used to shake a bit at odd speeds but new head race bearings/adjustment always cured it.

LotusSevenMan · Post by **LotusSevenMan** » Sun Mar 18, 2007 7:47 pm

Thanks Stratman.
I don't want the damn thing to fall over yet again!!!!!!!
I haven't got to check the bearings yet due to weather etc (in my open air garage) but it does sound like it could be the steering head bearing from advice on here and elsewhere!