Spooky Spooky Weave

Joined
Feb 22, 2015
Messages
30
Location
Tolland, CT
Bike
2007 ST1300
Hi all, and once again I appreciate any responses from the experts here that know these bikes much better than I.

I bought a used 2007 ST1300 two years ago with 27K on the odometer. Thanks to the forum I went all through it and put it in tip top shape for riding without problems. So for the first year I rode it about 4K with the old well worn PR3 tires. Compared to my other bike, a 2011 Harley Superglide it felt like a rocketship on rails. Wow, seams on the pavement, tar snakes etc. - nothing seemed to upset this bike.

Last year I treated it to new PR4GT tires as the PR3 were no longer available. They seem stiffer but similar to me. No other changes. No top box. Solo. 160 lbs. Bags lightly packed.

So coming back to CT from our camp in the Adirondacks I am enjoying the bike on the two lane roads at it is handling great. I get a ticket for 79 in a 55 zone because it feels so good. Then I get on the Mass Pike heading east at settle in at an indicated 80. About 15 miles down the road, behind an empty flatbed semi the bike all of a sudden feels like it has a flat rear tire. I pull to the side of the road and both tires are fully inflated. No choice, get back on an settle in at 60. Horrible spooky feel in the rear. Convinced the rear axle has come loose I pull over again. everything is tight. No choice - ride on looking for the next exit to get on two lane roads. By the next exit it feels fine and I continue home. At home, check tires and rear tire at 36 psi so I figure that is the problem.

Next week same issue. Ride up with no problems. Ride back and same issue in roughly same location. Very very spooky feeling and then it disappears. And it never happened with the old worn PR3s. I have looked at this section of road from the car and nothing out of the ordinary.

I R&Red the wheels and followed the service manual to the letter. Head bearings good. Rear shock in standard setting by the manual. Riding solo. Lightly loaded. Tire pressures spot on the second time. First ride of the year today and no issues. Love the bike but this scared me.

Any ideas? Thanks in advance for any replies.
 

dduelin

Tune my heart to sing Thy grace
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If the road was grooved that may have given the flat tire feeling. If road wasn't grooved and the bike is otherwise OK and still scares you just sell it and move on. These things don't weave at 75 - 80.
 

970mike

Mike Brown
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Your tires should be at 42PSI. Check that your rear shock has fluid in the pre-load reservoir as it could be empty causing you no Pre-load on the rear shock.
 
OP
OP
Joined
Feb 22, 2015
Messages
30
Location
Tolland, CT
Bike
2007 ST1300
Don't want to sell it - new tires, brakes, battery, fork seals, plugs, valves checked, brake fluid, air filter etc. etc. Really nice bike.

Bike was rock solid on that same section of road with the old tires. Guess I will try it again and see what happens. This time in the daylight.
 

BakerBoy

It's all small stuff.
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Jan 31, 2008
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I know what you mean... I've had a few instances where I thought the rear tire was going down and pulled over to check.

But the ST1300 doesn't weave at 75-80 unless something is WAY wrong. The weave maybe onsets on some bikes as low as ~120, with topbox and lots of unsecured weight up high, and unloaded 'preload'. But not 80.

Road surface, turbulence off of other vehicles (esp large trucks), and crosswinds flowing over the roadway can give a twitchy feeling, which many mistake as the weave.
 
OP
OP
Joined
Feb 22, 2015
Messages
30
Location
Tolland, CT
Bike
2007 ST1300
I did note that there was a tailwind both times. Prevailing winds from the west. And I do need to check the rear shock. It is the only thing I have not serviced and I remember reading a very good description of how to change the fluid elsewhere in this forum. Good suggestion and it definitely felt like the rear tire.
 
Joined
Sep 4, 2013
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8,108
Location
Cleveland
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2010 ST1300
I have to think that Dave was kidding about selling it. I don't think you could pry his bike from his cold, dead hands..... Anyway, I experienced an instability behind semis in the turbulent air after I rejuiced the rear shock preload and played around with the rear preload setting and rear shock dampening setting. The bike felt squirrely but only in the wake of large trucks or crosswinds. So, I turned the screw and the knob back to approximately where they were, and the funny stuff disappeared. As said elsewhere (MCN?) motorcycles have a number of resonant frequencies and when they match up and reinforce each other, watch out - that is what causes tank slappers. An 07 is still 10 years old. You might need to refresh the fork springs, fork oil(was that changed with the seals - I would guess so) change tires, (I doubt if the rear shock is worn at 27k miles) - anyway, it will take a bit of time to chase this down.
 
OP
OP
Joined
Feb 22, 2015
Messages
30
Location
Tolland, CT
Bike
2007 ST1300
Thanks for the input. I did service the front forks and since I don't know this bike all that well, I used Honda seals and fluid. Kept the stock springs. Fluid was nasty and glad I did it.

Based on what I'm reading here I'm thinking I should service the rear shock and maybe increase the preload. Set on the soft side now for comfort I'm light and ride so!o. My wife has her own bike. So if this happens again I guess I will pull over and change the preload. Did not think of that when it happened.
 

dduelin

Tune my heart to sing Thy grace
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It is counter intuitive but adding preload on the sag to minimize rider sag does help settle these bikes down. At least mine anyways. They are so softly sprung that using little preload barely keeps the shock off the bump stop at rider sag and when it gets a little up and down motion it actually starts bouncing off the bump stop. Especially for husky riders over 200 lbs. If you like little to no preload at least turn up the damping to 1.5 to 2 turns to over-dampen the oscillations. If the shock is stock and never been touched it's likely the preload adjuster is working at 50% of available travel which should be about 34 - 36 clicks or about 18 turns from fully CCW. It's an easy fix though - just refill the preload reservoir to regain the ~10 mm of preload adjustment.

FWIW after trying a few sets early on I quit mounting Pilot Roads in the 3rd generation. Michelin builds them with relatively soft sidewalls and the ride is plush but the tires are squishy and don't feel good in corners to me. They grip to the cows come home but offer little feedback through the bars. If the bike has the requisite pullback risers it's like steering a wheelbarrow with a soft tire. Bridgestones have been my go to tire on the ST. The guy mounting them will tell you they can be difficult to mount due to their stiff carcass construction. Tires alone make a good difference in manners in dirty air at 70-80 mph, the so-called "happy feet" feeling the ST has in slab traffic.

https://www.st-owners.com/forums/showthread.php?106715-ST1300-Pre-load-Fluid-Replacement

https://www.youtube.com/watch?v=CAhksxRCIik
 
OP
OP
Joined
Feb 22, 2015
Messages
30
Location
Tolland, CT
Bike
2007 ST1300
Thanks for the great links. This is the best forum I have ever been on! I have never even checked the rear shock for rebound and simply set the preload for whatever the manual suggested. While it may have worked for the old PR3 it maybe all wrong for the new tire. And some time and miles have passed too.

First bike I have owned with two separate hydraulic adjustments and I need to service this and get it adjusted asap. More convinced than ever that this is at least part of the problem. Thanks again.
 
Joined
Nov 12, 2013
Messages
91
Location
Encino, CA
I get an ever so slight funny mushy feeling in the back every time I go through 120. I'm not sure if it's my imagination or what, but it happens on the dot at 120. Once I pass through 120 the slight funny mushy feeling in the back goes away. It's almost like a low tire feeling. So, I never hang out at 120. Since its only just a feeling rather than any wild movements, I put it down to my top box, big windscreen, or some other weird aerodynamic anomaly. And character!
 
Joined
Feb 10, 2011
Messages
93
Location
Iowa
Bike
82 VF750S Sabre
Bike was rock solid on that same section of road with the old tires. Guess I will try it again and see what happens. This time in the daylight.
While not a motorcycle, both times I have replaced the tires on our Jeep Patriot, certain grooved concrete roads cause a bit of a sideways wiggle. It went away on the first replacements at about 10,000 miles and I think it is gone on the second replacements now that they have about 5,000 miles on them. Tire dealer for the second set said that the taller tread blocks squirm more than half worn tires.

So it could be the new tires trying to follow a slightly wavy groove.

Neal
 
OP
OP
Joined
Feb 22, 2015
Messages
30
Location
Tolland, CT
Bike
2007 ST1300
OK, think I have it. Put bike in chock and checked rear shock. It felt a little bouncy. Rebound set at 1 turn as recommended by Owners manual and left it there. Tried to service preload but could not get the little screw off the knob - like it is welded on!! Anyway, backed off the preload all the way and then started clicking in. NO resistance until 17 clicks. So it was set at 7 per the manual and I then assume I had absolutely no preload. For now, I went in 17 clicks until I had some resistance and then added 5 more clicks. Just using the bounce test in the chock it felt better.

Now for a test ride and back to the incredibly stubborn screw so I can service it but I am confident that no preload was the culprit. And thanks for all the great guidance.
 
Joined
Sep 22, 2015
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Wasaga Beach, Ont. Canada
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'04 ST1300 Blue STar
Not sure you need to remove the small screw that holds the knob on. Since your detents are working (clicking),,, they may not need cleaning yet. What you need is fluid. When I serviced mine,,, I did everything in the bike. I did not need to take the knob off either,, as my detents were okay. I just unbolted the preload adjuster from it's mount,,,, wound in about 2 fills of fluid, as per the threads on the topic. Re-installed,,, and done. Still works fine,,, after a season's riding. Interesting opinions on where the missing fluid actually goes too,,, some say hyper-space,, or evaporation. I suggest that it is more likely to seep gradually during long hot rides,,, when the shock gets totally heat saturated,,, from operation and engine,,, just a wild guess,,, Cat'
 
Joined
Mar 29, 2010
Messages
66
Location
Cheyenne, WY
Bike
'05 ST1300 "STinger"
It's probably a combination of 2 things, preload and tires. After a lot of research on this forum I cranked my preload up and most of the squirrely feeling went away. I have PR4GT's on my '05 and grooves in the road push me around more than any other tire / bike combination I've ridden. I'll be replacing them with Bridgestone T30's when the time comes. Hopefully that takes care of the rest of the squirrels.
 
OP
OP
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Feb 22, 2015
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30
Location
Tolland, CT
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2007 ST1300
Done! Serviced the preload adjuster per the simplified method posted by Igofar several years ago. It was nearly empty which explains why it took 17 clicks to engage. It now takes 1 1/2 clicks to engage. Igofar suggested setting the preload at 4 clicks after resistance and the rebound at 1 1/2 turns out considering I only weigh 155 lbs and ride solo. What a difference! On the highway behind a semi, yes there is a lot of buffeting but the rear end now feels planted and stable. Before, the back end wandered around and it felt like the rear tire was skating. Funny, but this was more noticeable with the new PRGT4 tires. Feels great now and I am back to loving this bike.

Thanks to all who made suggestions and a special thank you to Igofar.
 
Joined
Mar 26, 2017
Messages
42
Location
SE Michigan
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2006 Honda ST1300
Thanks, I just checked mine and the preload was nearly non-existent. Cranked the knob in until I felt tension, then four more clicks. We'll see how it feels on the road tomorrow.
 
Joined
Jan 8, 2011
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7,062
Location
Arizona
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2007 Honda ST1300A
Thanks, I just checked mine and the preload was nearly non-existent. Cranked the knob in until I felt tension, then four more clicks. We'll see how it feels on the road tomorrow.
Before you do that answer the email I just sent you.
Standing by the white courtesy phone :call:
 
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