Slow weave has me stumped

[FROSTY]

1996 YZF600 weave

Bringing my new toy home today I "noticed" a relatively gentle weave from about 5 degrees left to 5 degrees right riding in a straight line.
leaned over its less noticeable but still there.
Wheel apears to be straight,tyre is a dunlop that looks to be in good condition. bearings are fine and theres no "flutter" in the brakes/brake lever.
What does the KB brains trust think?

[Ixion]

What spped? I had a slow weave issue on von Klunken , that manifested at about 130kph (from memory). Everything looked fine, tyres looked good , all good. Stilla slow weave. Not frightening, not control threatening, set in fairly abruptly, didn't get worse with higher speed. Just weaved over the lane.

Went away like magic when I fitted a new, different rear tyre. You don't have Metzlers fitted by any chance ?

Anyway, I'd suspect the tyres. Maybe not BAD tyres, just the bike doesn't like them.

On the other hand I had a pronounced weave on Petal a while ago, to the extent that it took all by trying to keep her in one lane. Turned out to be 24 spokes broken in the rear wheel. How are your spokes ?

[cowpoos]

stop nodding your head while riding?

[Subike]

your riding the join in the ashpalt, or shingle tar join.
Its just the wheel following the road.
I got this and wondered what it was for a while.
You tyres climbing up and down the "edge" of the road makers join in the road surface.
Thats my answer anyway

[FJRider]

leaning into the wind ????

[xwhatsit]

On the other hand I had a pronounced weave on Petal a while ago, to the extent that it took all by trying to keep her in one lane. Turned out to be 24 spokes broken in the rear wheel. How are your spokes ?

YZF600s only have three spokes on each wheel, and they're not the sort that you can break or tighten :pinch:

I put a new front on my little bike, stopped a hands-off wobble that occured around 50kph, and the occasional slow weave that set in exactly at 105kph. Always controllable, always slow, but exactly at 105kph. Close the throttle then open it again and it'd stop, or keep going to 115kph and it'd stop (or back off below 105kph). Anyway, gone with a new front.

[Ixion]

YZF600s only have three spokes on each wheel, and they're not the sort that you can break or tighten :pinch:

...

Give it to me. I'll break them .

[FROSTY]

What spped? I had a slow weave issue on von Klunken , that manifested at about 130kph (from memory). Everything looked fine, tyres looked good , all good. Stilla slow weave. Not frightening, not control threatening, set in fairly abruptly, didn't get worse with higher speed. Just weaved over the lane. Went away like magic when I fitted a new, different rear tyre. You don't have Metzlers fitted by any chance ? Anyway, I'd suspect the tyres. Maybe not BAD tyres, just the bike doesn't like them.


your riding the join in the ashpalt, or shingle tar join.
Its just the wheel following the road.
I got this and wondered what it was for a while.
You tyres climbing up and down the "edge" of the road makers join in the road surface.
Thats my answer anyway
Nope dunlopd and in pretty good condition
Nope--I've just done 250km on it so its fair tosay Im not riding the tar snake the whole way

[Ixion]

Mine was in good nick too, annoying since I had to put up with it until I wore out the tire. Just didn't like that tyre for some reaons.

But, what speed? A weave at 40 kph is probably a different cause than a weave at 200kph.

[Ocean1]

loose front guard?
Had it once, it was bending one way and making like a rudder, then back t'other way etc.

[FROSTY]

Mine was in good nick too, annoying since I had to put up with it until I wore out the tire. Just didn't like that tyre for some reaons.

But, what speed? A weave at 40 kph is probably a different cause than a weave at 200kph.
now Thats the weird thing-it seems to be there from 20km/h right on up to 100km/h

[speights_bud]

Check that the rear axle adustment has been taken up evenly on both sides maybe, I've also noticed recently when following some other bikers through town that their rims are running what look to be nice and true but the tyre is running out, as in its running concentric with the rim but appears to 'wiggle' side to side when seen from behind.

i've come across this once when riding a bike that had a buggered rear shock and light front end... but i'd say your's would be in much better nick than that heap... that bike used to weave alot mid corner, i put it down to poor suspension setup

[The Pastor]

I once rode an xj600 (or was it 650?) from welsford to whanagrei. It weaved all over the place, almost like it was on knoblys at 160km/hr. Scary.

[Kittyhawk]

Checked wheel alignment of tyres? rear one not slightly out or something?

Maybe slight air bump in a tyre somewhere,

[xwhatsit]

Checked wheel alignment of tyres? rear one not slightly out or something?

That won't make it weave, though, just crab across the road. Oblig. DAMHIK :nono: Front wheel being out of alignment is normal, at least in corners :mellow:

[Drew]

Christ almighty people, start simple, and work up from there. I'll put $20 on it being steering head bearings a touch too tight, lots too sloppy, or just a fraction buggered.

Mr Frost, take your hands off the bars at 50kph and see what happens. It'll either try and ride off the road, or start a gentle shake turning into a violent one the longer you leave said hands off.

[FROSTY]

Drew --Nope mate -did that on the test ride--Took it to the servo put air in tyres--yea i know not accurate but I was 250k from home.
Then off for a ride.
Put bike in neatral at 100km/h sat upright -gentle weave slowwing to around 40km/h-still a gentle weave
Very light pressure on brakes -No pulsing
Back to the guy selling it-Haul her over onto her sidestand and had his son balance it on back wheel/sidestand.--again 250 from home--ya do what ya gotta do.
grab the wheel -no bearing clunk--spin it--all good-
Check wheel runout with ye ol screwdriver on the forkleg-no visible runout.
Turn steering left to right -smooth with a tiny bit of resistance-
Grab wheel--tryn haul it back n forwards --nope tight as.
HMMMM

[enigma51]

Drew --Nope mate -did that on the test ride--Took it to the servo put air in tyres--yea i know not accurate but I was 250k from home.
Then off for a ride.
Put bike in neatral at 100km/h sat upright -gentle weave slowwing to around 40km/h-still a gentle weave
Very light pressure on brakes -No pulsing
Back to the guy selling it-Haul her over onto her sidestand and had his son balance it on back wheel/sidestand.--again 250 from home--ya do what ya gotta do.
grab the wheel -no bearing clunk--spin it--all good-
Check wheel runout with ye ol screwdriver on the forkleg-no visible runout.
Turn steering left to right -smooth with a tiny bit of resistance-
Grab wheel--tryn haul it back n forwards --nope tight as.
HMMMM

I reckon its the dunlops

Shit tyres!

[Drew]

Drew --Nope mate -did that on the test ride--Took it to the servo put air in tyres--yea i know not accurate but I was 250k from home.
Then off for a ride.
Put bike in neatral at 100km/h sat upright -gentle weave slowwing to around 40km/h-still a gentle weave
Very light pressure on brakes -No pulsing
Back to the guy selling it-Haul her over onto her sidestand and had his son balance it on back wheel/sidestand.--again 250 from home--ya do what ya gotta do.
grab the wheel -no bearing clunk--spin it--all good-
Check wheel runout with ye ol screwdriver on the forkleg-no visible runout.
Turn steering left to right -smooth with a tiny bit of resistance-
Grab wheel--tryn haul it back n forwards --nope tight as.
HMMMM
Without weight on the wheel and bearings it is quite often not noticable that there is a "notch" when turning the wheel.

For the sake of thirty bucks just change 'em mate.

[FROSTY]

Im kinda thinking that myself. I thought yea cool toss a saet of my old race tyres on--new wheel and SH bearings in
SUCKS--the 96 YZF has a 110 front

[Kittyhawk]

That won't make it weave, though, just crab across the road. Oblig. DAMHIK :nono: Front wheel being out of alignment is normal, at least in corners :mellow:

Ok so crabbing isnt the same as weaving...Im a newb lol..:sweatdrop

[Grub]

What about the swing arm? If the weave is a slow lazy one then the swing arm is the only thing that has a long enough moment to generate that low frequency I would think. I don't have a clue as to how you check such a thing though.

from your description it sounds as if it doesn't get faster with speed? Just the same lazy weave? If that's the case, it can't have anything to do with wheels, Drew's thoughts about steering head sounded good but your tests seem to rule that out.

there is one other possibility of course, :eek5: broken/cracked/soft frame! That's the only other thing i can think of that would have that low frequency - and that would be Bad.

[enigma51]

Case of beers says its the tires

[homer]

Are the tyres balanced

[scrivy]

One fork got less/more fluid or preload etc than the other?
Has the bike been jacked up at the rear or lowered at the front??
(If ya had 3 wheels - then it wouldn't matter!) :lol:

[Drew]

One fork got less/more fluid or preload etc than the other?
Has the bike been jacked up at the rear or lowered at the front??
(If ya had 3 wheels - then it wouldn't matter!) :lol:

We've covered this, rigs are for devients! And Frosty aint tough enough to get away with the shit your type gets up to.

[FROSTY]

We've covered this, rigs are for devients! And Frosty aint tough enough to get away with the shit your type gets up to.
OYY-- Ive raced trikes a couple of times thank you.
Trouble is when ya do solo's back to back with trikes you take lines that put ya swingers head VERY close to the haybales. -Read that as the poor sod had hay stuck in their visor after one lap --ooops

[Mike748]

Im kinda thinking that myself. I thought yea cool toss a saet of my old race tyres on--new wheel and SH bearings in
SUCKS--the 96 YZF has a 110 front

I'm with Drew, if it were the tyres or rims I'd expect the weave to vary with speed but as it appears constant throughout such a large range of speed I suspect movement in SH bearings, or as Grub suggested the swingarm.

I'd expect the weave to reduce when on a lean as the frame is loaded up and not neutral.

....... So have you solved it yet?

[FROSTY]

with my post count today Im at work so no no chance to get down n dirty on the bike

[Mental Trousers]

Swingarm bearings or rear wheel bearings??

[Devil]

Is the front wheel in the right way round?

Bars/clip-ons straight?

[Drew]

Swingarm bearings or rear wheel bearings??

My experience only, but swingarm bearings only cause issue in corners, (That was when they were beyond sloppy, and at the stage of being totally lose).

And wheel bearings cause a higher frequency type weave, kinda shakey shakey type deal.

[codgyoleracer]

Yip to order of checking, to tight steering head or worn, correct torque on swingarm (or worn), wheel alignment (stringline), if no strange wear patterns on tyres they shud be fine (some front dunnies run pretty high pressures though)

[riffer]

Yup. My money's on the steering head being just a tiny bit too tight for the bike's liking.

My FZR750R was a bit like that. You had to either have it loose enough that headshake was a bit of an issue, or tighten it so you got the tiniest of weaves.

Have you pulled the top triple off Tony? Those deltabox frames are reeeeeealllly susceptible to the front on bang and it can ovalise the steering head races slightly causing the bearings to just grab in the middle.

What's the wear pattern on the front tyre like? Are you getting feathering on the leading edges of the tyre pattern? That could be indicating something giving you grief.

110 section? yuck. Try a 120 and see if it smoothes off riding on less of a knife edge.

[F5 Dave]

That won't make it weave, though, just crab across the road. Oblig. DAMHIK :nono: Front wheel being out of alignment is normal, at least in corners :mellow:

No that's exactly what wheels out of alignment will do. That's why racers string line their wheels. not so noticeable at mid speeds but at low speeds the bike will wander in small oscillations & you'll think you're going crazy till you realise that it isn't you. Tends to show up again as instability at high speeds.

I've seen bikes that would weave when set up to the stock swingarm marks but needed to be adjusted 5mm off to get them running straight (and weave disappear completely). A crash may do this, but they are sometimes out from factory. I find a long bit of square tube the easiest for checking wheel alignment, string just seems too confusing to look at for me, but some people like it.


Course naff steering bearings will produce a similar effect as noted. Worn rear tyre will tend to make handle bars shake when slowing down, but not ness the same.

[tri boy]

Do the cheap things first. Tyre pressures, wheel alignment, Check triple clamp alingnment, SH bearings, wheel brgs. All cheaper than a set of tyres, and swingarm/suspension O/haul.
Good luck.

[FROSTY]

Im gionna bung a new clutch in it then take it from there

[Grub]

Ummm ... yer .... that should fix the weave .... :whistle:

[Reckless]

Check to make sure he hasn't had the front wheel off.
Took my old Z to Cycle treads and got new tyres on it once. Had a weave from 120k on after.
I thought for months it didn't like the newer shape tyres until one day I took the front off wheel off.
The Axle wasn't seated properly on one side. Throwing the wheel out, balanced ok, running true, but on a very slight angle.
Its worth a look anyway, won't cost you anything!

[FROSTY]

Ok I could do the puffed up chest thing and tell yas about stringlining this and adjusting that. Truth is though I made the most neeewb of newb mistakes. I trusted a shitbox gasstation pressure gauge.
Checked the tyre pressures tonight before a ride and bingo 24psi front and 30psi rear. Put air in tyres and weave has gone.
Now the bike just has all the expected traites a 1995 80k motorbike is expected to have

[speights_bud]

:whistle:

hehe, coulda happened to anyone i guess... at least it was a cheap fix :clap:

[Maha]

:whistle:

hehe, coulda happened to anyone i guess... at least it was a cheap fix :clap:

Hard case for sure, why did the 'KB Brains Trust' NOT come up with this on page one??....:confused:

[F5 Dave]

'cause we all made an assumption & we all know about assumptions don't we? They make a sump . . . um, :wacko:no wait, there's a trick to this.

Ohhh, they make a, . . no.

Must be something else I was thinking of.

[Drew]

'cause we all made an assumption & we all know about assumptions don't we? They make a sump . . . um, :wacko:no wait, there's a trick to this.

Ohhh, they make a, . . no.

Must be something else I was thinking of.



No no no, assumption, is the mother of all fuck ups.

[martybabe]

Don't assume, it makes an ass of u and me.

Glad you sorted it, it's a bastard how little things piss around so much with the way a bike behaves init. ;)

[svr]

I trusted a shitbox gasstation pressure gauge.
Checked the tyre pressures tonight before a ride and bingo 24psi front and 30psi rear. Put air in tyres and weave has gone.


Geez Frosty what a waste of 15 mins reading the whole thread thinking `pump yer bloody tires up'. Then ya did.
Anything that interferes with continual alignment corrections between the wheels right? Excessive tyre carcass distortion seems to be most common.
Never fixed my old 83 RZ350 tho - then got shown a photo of it upside down 10 feet off the ground with previous owner Terry Fitz still hanging onto a handlebar. Mystery solved.

[FROSTY]

yea well just shows -In my mind Id ruled out tyre pressures -even though everything pointed to it

[Reckless]

Haha frosty you have won "chump of the week" LOL

Like that ad where that guy has 1/2 the country looking for his Corolla keys!
You had 1/2 KB looking for a weave.

At least it only cost a bit of air. 10 Points for admitting to it as well!!