front end shake

[travelingman]

Any of you ever have a front end shake at about 30 to 40 mph if you
relax your grip on the bars ? Replaced the head bearings an races can't
say it really changed anything . I've got them as tight as I dare an still
have the bars bars fall from left to right with out binding . I'm begening to
wonder about the tire even though its new . It's a Dunlope K59 1F Elite
190/90-19-51V . Any suggestions ? I plan on getting a stablizer for it but
it never use to do this .
Also I have a Dina 3 IGN on this bike that was installed when it was new but I'm still running the stock coils what would be a good match up for this
old system ? In a hotter coil . An should I see a big differnce in a smother
running motor with everthing else in good condition an proper tune ?

[chrisNI]

Sound like the tyre. You can get a faulty new sometimes they don't wear even if yours is new it could be faulty, or it could be your wheel out of true if it's a spoke, chances are it's one or the other.

My 1000R did that for a while a new tyre fixed it.

[london calling]

If you need to get a new tyre,my choice would be a Bridgestone BT45 Battlax.Make sure your wheel is true and properly balanced.Sometimes different makes of tyres front and rear can affect handling,etc.
For advice on coil selection speak to Jeff Saunders at Z1 Enterprises.
www.z1enterprises.com

[Sorf]

Mine does exactly the same thing. I have an Avon Speedmaster on the front. I do know that my swingarm bushes are a bit sus, so was hoping that this will right itself once the bushes are replaced.

[Hack]

Just a thought but when the tyre was replaced was the wheel re-balanced?

Also, is there anyone else local with a Z who could loan you a front wheel for a test ride, at least that way you would find out if the problem is with your wheel/tyre before spending any cash.

Andy

[rickman CRR]

Before you start changing tyres, make sure the front tyre is at the correct pressure. Simple thing, easily overlooked.

[Iain marshall]

and who had that problem a couple of time Colin?

[Steve R]

Are The new head bearings taper or original ball bearing type?

Have you overtightened the bearings? this can cause low speed weave.

Did the races seat properly?

Did you replace the tyre at the same time as the bearings, if not can you say it was def. bearings that changed it?

Check run out on on wheel: put on centre stand with front end in air, spin front wheel with pointer next to rim is it running true? with pointer on edge of rim is it running round?

Was tyre balanced? Correctly? Again spinning wheel should stop in different place each time (make sure brake pads are not dragging) if it stops in same place its not balanced.

Is tyre fitted correctly should be a line round tyre which should be equal distance from rim all way round, on both sides!

Are wheel bearings ok?

It should not do this and you do not really want to just mask a problem like this by fitting a steering damper.

Let us know how you get on.
Regards Steve R

[rickman CRR]

iain

You live and learn.....lol

How're things?

[Pigford]

travelingman, you said you'd done headraces up tight as you dare! Better to be on loose side that too tight as this will make it weave at slower speeds!
if it was OK before retrace your steps!

[chrisNI]

if it was OK before retrace your steps!

Which was something I wondered about after I'd posted about the tyre... When was it okay?

[Keith]

sun was out today and so was the z

first outing with new tyre on and it started doing exactly the same thing - mine is a slow side to side oscilation on the bars from about 15 up t0 35 mph - ok otherwise right up toover the 100 mark

presuure is right and tyre seems to be seated right - but will now do some of the other suggested checks

keith

[Garn 1]

Travelingman, as Sorf mentioned above, I have heard that excessive play in the swing-arm will reflect into the steering head and give that shake effect at low speed, though, I'm sure you would notice the wobbles at 100MPH with a loose swing arm. See if you can nail the problem and let us know!
Have you the usual crack in the Z1 series steering head support bracket?
Taper rollers in steering head is a must!
RegardZ.

[Keith]

well the wheels off and investigating!

axle spindle and wheel rim look to be in true and tyre seated correctly - off tomorrow to get balance checked - will post results after a "good" test run

keith

[Steve R]

Good Luck,
Will be interested to see what the solution is, suspect head bearings too tight is most likely.