Front tire weaving / fishing

GreenDagger

Joined
May 16, 2014
Messages
3
Location
Tacoma, WA
ANY HELP? Just got 1st ST (2003 ABS), but this can't be 'normal': feels like front tire is 'fishing' back'n forth. More pronounced at freeway speed. New tires, Metzeler RoadtecZ6 120/70 ZR18 steel radial, mounted correct rotation (arrow), 42 psi. On my test drive I just thought the lane had worn tracks and the bike fished around in the groove. Not so, or else almost all our roads have wagon tracks. Only other factor is non-stock Cee-Bailey shield. Does NOT feel like it's about to spiral out of control, but UN-nerving & no fun. Almost makes me want to leave it in my garage! What's going on?
 
The type of pavement will change the ride characteristics as you noted.
Also be aware of the traffic around you. I find the weave more pronounced on the freeway if I'm following 18 wheeler trucks. Also the type of trailer they are pulling will affect the weave. Car carriers are the worst so far for me. Containers on trailers are next. The trailers the have a cone shape at each end (barley or cement bulk carriers) are barely noticeable.
I have a stock windshield on and mostly drive with it in the fully raised position.
 
how many kms / miles has the bike done?
start with the simple, then proceed to complex.
get the bike on centre stand and with a helper sitting on the rear seat, or place a jacl under the sump so the fron tyre is free to spin.
set a ruler/pencil, coat hanger, anything you can fastened to the fork or event front fender and align as close as possible to the wheel rim.
give the wheel a slow spin and check for run out. if the bike has had a hard meeting with the curb or accident this will show up. check the workshop manual for run out tollerance, it should be very minimal if at all.
you may have a bad rim.

so I would start in the following order and continue to the next step if no fault found:

1) check rim run out as detailed above
2) properly seated tyre, evenly and correctly all the way 360.
3) lock the steering with the key, and try to feel for excessive wheel bearing play by attempting to "twist" the tyre between the forks, any wobble or clicking play means bad bearings.
4) spin the front wheel and listen for bearing noises at the front axle, it should be whisper quite with no grinding noise, carefull not to confuse with brake pads, you may have to pull the callipers out to be sure.
5) check that the axle bolt is torquesd correctly to spec in book
6) compare the top of the fork stancions to see if they are set at exactly the same hieght, if not reaalign as per manual and tighten to spec.
7) check main steering stem for tightness and bearings for wear as per manual, a big job if bearings need to be replced, but may be required, wheel needs to be removed
alternatly a good bike mechanic should be able to give you a diagnosis and quote to repair in 30 min of testing....

good luck, does not sound normal as you should feel confident. my bike is very much, "point and shoot, hands off 'bars straight as an arrow at all times"
 
Since I ride an 1100, I'm not sure what the tire pressure spec for the 1300 front is, but 42 psi sounds too much to me. The 1100's are usually run at 36 to 38 psi front pressure. Over inflation equals smaller contact patch equals skittish front end.

Also, if the tires are BRAND NEW, it does take about 100 miles of riding to wear off the mold release compound, which makes a tire dangerously slippery at first.
 
Last edited:
Are the tires in good condition? 42 psi is correct for the front of the ST1300 (and 42 psi in the rear).

The bike does twitch a bit--it's in part due to front rake angle, but also due to aerodynamics. If you have a tailbag or trunk in place, it will be more pronounced. If you're around another vehicle, you'll notice the twitchiness (this is not weave ... weave is different, specific high-speed problem).

You can reduce it a bit by loosening any tight upper torso or arm muscles.

Some will say that rear spring preload affects this twitchy feeling ... it may affect it very, very little. To prove that, run the rear preload completely unloaded, then tighten it fully and run it (there will be no effective difference in the twitchiness, as there is virtually no bike geometry change by adjusting preload).
 
Sounds like you need to make some adjustments on the suspension, check out your forks for fresh oil and good springs, re-fill your pre-load adjustment mechanism and set it up for your weight.
 
SteveST1300 said:
check suspension first make sure pre-load is cranked up a bit.
Click to expand...

+1... on the bike the preload can effect how the front feels.

Since you said new tires, I would PROPERLY reset the front end by following these steps just to eliminate the possiblilty.

(Note: Axle pinch bolts are finger loose at this point)

1. Tighten the left axle pinch bolts to 22 N-m (2.2 kgf-m, 16 lbf-ft)
Note: Indication of “Left” is if you were sitting on bike
2. Tighten Axle Bolt to 79 N-m (8.1 kgf-m, 58 lbf-ft)
3. Tighten the right axle pinch bolts to 22 N-m (2.2 kgf-m, 16 lbf-ft)
4. Now loosen the left axle pinch bolts
5. Note: During the assembly process, this is where you would be installing the brake calipers.
6. Set the bike down where the bike's weight is on the wheels. Lock the front brake and push the suspension up and down several times.
7. Tighten the left axle pinch bolts to 22 N-m (2.2 kgf-m, 16 lbf-ft)


Always do the simple things first , esp rechecking things that just changed!
 
Last edited:
I though the same thing after I posted about the pre load Tom. Also check to make sure the spacers are on the correct side of the wheel.
 
Do you have a heavily-loaded trunk or saddlebags? Rearward weight bias will also affect the stability of the front tire.
 
Lots of good suggestions posted above. I have run many Z6's and doubt it's the tire. If you don't know the history of the '03, you'd want to know if the fork bushings are worn, steering head not loose/torqued properly, and rear preload adjuster actually works (may need oil refill?). Also, I'd say not to run lower pressure than 40 psi with that tire.... 36-38 is too low (IMHO on an ST11 too). If your rear tire is worn (flattened), it can contribute some to 'hunting'.
 
When all else is exhausted we come back to the fact the ST1300 isn't especially stable at speed particularly in traffic. To some riders this trait, the "happy feet", is very off-putting and in some cases frightening.

It isn't dangerous and the bike isn't getting ready to spit you off but it can be unnerving until gotten used to.
 
Service preload adjuster and add fluid to unit -search threads-check condition of rear tire -empty or remove bags and or top box- check front wheel assembly as stated - check smc and brake system to make sure rear caliper is not dragging or grabbing. Place shield in lowest position and turn preload fully soft - will allow rear end to settle more. Let us know what you find.
 
We will agree to disagree with turning your preload to fully soft unless you weigh about 120lbs I don't think that is correct follow posted instructions and set your sag properly fron and rear.
 
SteveST1300 said:
We will agree to disagree with turning your preload to fully soft unless you weigh about 120lbs I don't think that is correct follow posted instructions and set your sag properly fron and rear.
Click to expand...
+1 Its counterintuitive but riding an ST1300 at speed with soft or no preload is not anything I'd want to do or recommend to even a light rider and I am one. Any road irregularly and the rear of the bike starts moving up and down feeding forces into the frame and forks making the instability worse. Riding on sufficient preload minimizes movement and keeps the rear end planted. That's my experience at any rate.
 
Check to see where your damping adjuster is set at. The PO might have it set in an unfavourable position.

The rebound damping adjuster is right under the rear shock coil spring on the right side.

There is a punch mark for reference on the damping adjuster.

To adjust to the standard position:

1. Turn the damping adjuster clockwise until it will no longer turn (lightly seats).
This is the full hard setting.

2. Turn the adjuster counterclockwise approximately 1 turn so that the punch
mark on the adjuster aligns with the reference punch mark. This is the standard position.

To Reduce Rebound Damping (SOFT):
For a light load and smooth road conditions, turn the adjuster counterclockwise toward SOFT (S).

To Increase Rebound Damping (HARD):
For a firmer ride and rough road conditions, turn the adjuster clockwise toward HARD (H).
 
My experience with a worn (~2K) Z6 front on my ST1100 was quite similar. Dual compound quickly wore into a twitchy, wandering "V" that actually required back-pressure to keep it from falling further into a turn. Others seem to accept this/get used to it; I couldn't and pulled the Z6 early for a well-known neutral handling tire (OEM Exedra bias). FWIW YMMV

John

via iPhone 4S
 
Last edited:
Wow, overwhelmed by the depth and breadth of response! Thank you all for such quick and thoughtful tips. It will be a busy weekend checking into this. I bought bike from private party who turns out only had it ~ 6 mo. Bike has 9700 miles. Took it to shop after buying for combined 8k & 12K service just to be sure & for a bad turn signal switch. They checked tire, suspension, bearings as OK. Hadn?t articulated my concerns carefully yet by then. Checking with 2nd shop next week when I can be there to talk / listen while he?s testing. I will be getting a torque wrench to go with my service manual, although I was attracted to the rock-solid low maintenance rep of these bikes.

This is not a slick, skidding, traction-loss effect ? grips well on braking. Not really a twitch. Not the notorious high speed tail weave (really does feel up front) ? not a vibration or thumping ? front end is just light, not grounded ? wanders and fishes back & forth ? much like you?d expect from the well worn truck lanes on the freeway to feel. Am very encouraged to hear that solid confidence and predictability can be had; or at least a little light-footedness might not mean un-glued.

Specifics, in aggregate:

Bike load / balance: I do have the OEM trunk and usually carry some, but not max loads ? clothes, bike cover, etc. Worse on some roads than others, but both 1-up and 2-up w/ wife. Did not notice big change with adjusting rear pre-load, but wasn?t looking for correlation then. Excellent reminder of keeping a loose grip BakerBoy, the bar risers help, but do get tired throttle hand.

Tires: Metzler Z6 tires really are near new ? no perceptible diff in tread depth from center to edge ? still little nibs on side wall. No scuffing, bulges, bumps, cups. I did see mixed comments of others on Z6 tires on this site. Will get a really good gauge and experiment with psi.

Suspension / rims: Runout not perceptible at Rim, < 0.5 mm both side-side and radially at circumference; Tire circumferential runout ~1 mm; seating ring on side of tire matches rim well; Right fork tube is maybe ~0.5mm higher on triple clamp than the Left tube.

I need a torque wrench for most of the other stuff, and will have the shop dbl check. Very much appreciate the methodical step-by-step specifics, guys, along with the broad picture views.

Al Gully, I want to know more about your uni-go experience. I want (I think) a small trailer for camping gear with two-up. Physics of single wheel sound great if you can get a mount on the rear axle instead of frame mount. Is axle mount possible on our ST1300A?

Will post outcomes, thanks 3x over, -gd
 
9700 is like brand new in our world.

If you don't find the bike was wrecked then it sounds normal. Once you get tires and rear shock sorted out the happy feet allows the 730 lb ST to handle like a 200 lb lighter motorcycle.
 
GreenDagger said:
Just got 1st ST (2003 ABS), but this can't be 'normal': feels like front tire is 'fishing' back'n forth. More pronounced at freeway speed. New tires
Click to expand...

Ugh. So I fell asleep on the couch last night ... just woke up and what do I do? I check on the latest posts at st-owners :)

People think I'm nuts about this, but I get the same sensation. My description of this is it feels like the ST's front tire is gliding on ice.

At times, the sensation so completely freaks me out that I pull over and inspect my tires, thinking one is going flat. I'm not referring to the "high speed wobble" this bike is noted for ... this sensation happens at 50-60 mph ... and no, no trucks around me or excessive traffic - I can be on a lonely road, be it concrete or black-top.

I do feel more "confident" on a road that is rough - I think it's because of the road's feedback to me. Smooth roads seem to intensify the sensation.

I've done all the typical ... refreshed the pre-load adjuster's fluid (it took 20 clicks before I felt pressure - now it takes 2 clicks) and have had the pre-load at different settings. It helps a little, but the sensation is still there. I've re-done the front axle pinch bolts \ axle nut. I've checked for rim run-out. I've checked the steering bearings. I've checked the front wheel bearings. I've run the tires at 42, 40 ... no change. I've moved the windscreen to its lowest position. I take the top-case off. No difference (though the sensation is intensified with the top-case on).

What's really odd about this is that when I bought the bike, we rode the bike back (~ 3 hours) in some challenging conditions, most notably 30-40 mph cross-winds. It had a RoadSmart (I) on the back, about 75% worn, and the front a 30% worn Avon Storm ST. I continued to ride the bike without the sensation - always felt confident. Then I put on new Pirelli Angel GTs and I feel it.

I've spoken with "igofar" about this - he thought the "feels like I'm on ice" was a pretty good description - his opinion is that the driven-flange bearings are probably not up to par. I've yet to replace mine, but I'm thinking this is partly the issue. I think the new tires (~1k miles now on the Pirelli's) are partly at fault and also, because they are new, they are revealing faulty driven-flange bearings. I also think the front rake contributes a bit to this. And maybe the rubber-mounted handlebars.

I'm very tempted to put the well-worn Avon Storm (front tire) back on just to see if it has an effect. And I will replace the driven-flange bearings soon, just because they probably need it (if for no other reason).

But yea, I hear ya ... it's an very freaky (you'll pardon the 70's expression) sensation, so you're not alone.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom