New PR4 GT's installed, now have handlebar wobble below 50 mph.

[gsforster]

Have to give a shout out to the forum for some help here. About a month ago I installed new tires before a trip. and right away I noticed a steering wobble below 50 mph as soon as grip is released from bars. I normally keep a fairly relaxed grip on the bars and can feel the wobble, if I let go it gets much more pronounced. It's not a weave, but a front end wobble. I do all my own installs as I have access to a tire machine at work, and balance using a stand, have never had a problem until now. Steering head bearing were replaced 3 years ago, no notchiness detected or play, I double checked the drag with a pull scale, right around 3 lbs pull so right in spec. (bearing are oem ball bearings) Front axle bearing replaced 2 years ago (oem parts) smooth and no roughness or play detected. I thought I had a defective front tire so got the supplier to warranty it and send me a replacement. Same result. I took my trip anyway and all the while it had this issue, no obvious lumps or problems noted in either tire. I rode about 5000 miles on the trip - above 50 it feels fine even at interstate speeds. Now I'm back home and decided to get this sorted. I thought for sure I must have a defective rear tire that is setting this up, so I swapped it off for a used but still good T30 evo rear that I had. Exactly same wobble arrrgggh!! I have the used matching front t30 evo that I am going to mount tomorrow to see if that changes anything, just so I can eliminate the possibility that it could be something with the bike. Wobble seems more punctuated with my pillion riding along, but is still there solo riding. I checked rear preload is working and not low on fluid, knob meets resistance after 1 turn (topped up my preload fluid about 3 years ago). Do you think it's possible that I got 2 bad michelin front tires or has my ST suddenly decided it does not like michelins? Thoughts? Igofar? Help?

Cheers,
Geoff Forster

 

[Mistergemas]

I have Michelin Pilot Road 4 GT on both front and rear wheel on my 07, have never experienced any wobble. The bike is steady as a rock at any speed. Hope you find out what's causing this and let us know. Best of luck.

 

[Larry Fine]

Suggestion: Without changing anything else, see what happens if you lower the rear of the bike a bit.

Reasoning: Your rear tire is also new, and may be taller in comparison to the front than previous sets.

 

[CYYJ]

Geoff:

This is kind of a 'shot in the dark', but perhaps read these articles about ST 1300 wheel installation & wheel bearing issues, and see if you find anything in them that might help you:

ST1300 - Front & Rear Wheel Install and Front Axle Animation

ST1300 - Fitting Wheel Bearings - What the manuals don't tell.

I suggest these articles because from what you have written in your original post, it sounds like you have investigated and ruled out all the obvious causes (defective tire, steering head bearings, etc.). This causes me to wonder if the problem you have might be related to alignment.

Michael

 

[lomita]

Have to give a shout out to the forum for some help here. About a month ago I installed new tires before a trip. and right away I noticed a steering wobble below 50 mph as soon as grip is released from bars. I normally keep a fairly relaxed grip on the bars and can feel the wobble, if I let go it gets much more pronounced. It's not a weave, but a front end wobble. I do all my own installs as I have access to a tire machine at work, and balance using a stand, have never had a problem until now. Steering head bearing were replaced 3 years ago, no notchiness detected or play, I double checked the drag with a pull scale, right around 3 lbs pull so right in spec. (bearing are oem ball bearings) Front axle bearing replaced 2 years ago (oem parts) smooth and no roughness or play detected. I thought I had a defective front tire so got the supplier to warranty it and send me a replacement. Same result. I took my trip anyway and all the while it had this issue, no obvious lumps or problems noted in either tire. I rode about 5000 miles on the trip - above 50 it feels fine even at interstate speeds. Now I'm back home and decided to get this sorted. I thought for sure I must have a defective rear tire that is setting this up, so I swapped it off for a used but still good T30 evo rear that I had. Exactly same wobble arrrgggh!! I have the used matching front t30 evo that I am going to mount tomorrow to see if that changes anything, just so I can eliminate the possibility that it could be something with the bike. Wobble seems more punctuated with my pillion riding along, but is still there solo riding. I checked rear preload is working and not low on fluid, knob meets resistance after 1 turn (topped up my preload fluid about 3 years ago). Do you think it's possible that I got 2 bad michelin front tires or has my ST suddenly decided it does not like michelins? Thoughts? Igofar? Help?

Cheers,
Geoff Forster

What inflation pressure did you use on the front?

 

[gsforster]

Geoff:

This is kind of a 'shot in the dark', but perhaps read these articles about ST 1300 wheel installation & wheel bearing issues, and see if you find anything in them that might help you:

ST1300 - Front & Rear Wheel Install and Front Axle Animation

ST1300 - Fitting Wheel Bearings - What the manuals don't tell.

I suggest these articles because from what you have written in your original post, it sounds like you have investigated and ruled out all the obvious causes (defective tire, steering head bearings, etc.). This causes me to wonder if the problem you have might be related to alignment.

Michael

Thanks for the info. When I changed the front wheel bearing I was very sure to install exactly as the manual described and also as described in your link. No binding noted in front wheel after bearings were replaced (only very light drag from the seals) . The only thing I changed was the tires and now I get wobble.....

 

[gsforster]

What inflation pressure did you use on the front?

42 psi front and rear always

 

[Larry Fine]

My experiment suggestion is free and relatively quick and easy.

 

[gsforster]

My experiment suggestion is free and relatively quick and easy.

This is a good idea I will try this out. I have noticed the wobble is a bit more with my pillion riding on the back than without. My other thought related to this is possible sagged front fork springs?

 

[lomita]

When is the last time the fork oil was changed?

 

[gsforster]

When is the last time the fork oil was changed?

2 years ago

 

[Gus1300]

axle spacers verified correct?

 

[ToddC]

Did you loosen the front forks at all???
T

 

[gsforster]

axle spacers verified correct?

Just re-checked and verified against shop manual

 

[caldercay]

If you havent tried these ...

When you feel the wobble, pull the clutch in - wobble still there?
What about if you apply the brakes during the wobble?

EDIT: just realized something - I had a similar issue with the 2008 ... the front axle nut was missing.

 

[gsforster]

Did you loosen the front forks at all???
T

No, I did not loosen anything on the triple clamps, just the front axle/wheel/caliper mounts to do tire change. Handlebars seem dead straight going straight ahead so leads me to assume the fork legs are straight in the clamps.

 

[gsforster]

If you havent tried these ...

When you feel the wobble, pull the clutch in - wobble still there?
What about if you apply the brakes during the wobble?

Yes wobble still there with clutch in, have to have light finger and thumb squeeze on the clutch however or else my hand will dampen out the wobble. I have not tried it under braking will go and try that as soon as it stops pouring rain here lol.

 

[ToddC]

As rare as it could be...a bad tire from the factory....??
T

 

[sirbike]

This is interesting to me.
I bought my 06 double dark side. Rode fine.
Put a pair of wheels with 900 miles on the bearings and PR4GT tires on.
Wobble 45-55 mph, peaked at 50mph. I am normally comfortable with my hands off the bars. No way with this. Not bad with hands on.
Picked up an 03 with very good condition PR4GT front and back. Dead smooth.
Getting up around 13,000 miles the wobble increases slightly but impressively has done all these miles without getting as bad as I would expect.
Switch to a new Dunlop sport max 2 in front because it is $55 shipped and hope to use it up quickly and a slightly used PR4GT on the previously dark side wheels. Dead smooth.
Rim run out on the wobbly tire rim combo is a mm. Round is good, no dents. Tire looks true to the rim. This should be in spec.
The variable that I want to check is wheel weights. Out of three front wheels, the wheel with stick on weights wobbles. Weight was distributed almost evenly. I would not think this could make such a difference.
Just data.

 

[lomita]

Rear swing arm bearings ever checked?