OzSTOC
General Category => General Discussion => Topic started by: spanner on November 11, 2014, 11:49:38 AM
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So on a recent trip from brisbane to townsville (ride report to follow later) I noticed at certain speeds -- some legal and other definitely NOT my ST1100 would develop a serious speed wobble.
Also when cornering reasonably fasts .... but still legal. ... to the left i would also get a bouncy wobble .... but not when going to the right.
As a new STeed owner is this something that they just do or is this possibly a wheel balance or suspension issue?
I am not currently mechanical in ability despite my moniker! ....see how did you get your nick name for further details!
so the speeds the wobble occours at are around the 30 to 40 kph i get a kind of "weaving" or slalom effect .... not a safety issue but kind of off putting and a little annoying
the left hand speed bouncy wobble is when cornering at speeds of 80 to100 kph usually on a medium to longer sweeping corner.
the other speed wobble which will not be an issue in reality was when i was opening her up on a straight clear viz country road ..... and lets me just say that this speed will be rarely ever attempted again as I was just wanting to see what she could do ...... i have never been that fast before and most likely wont again but the STeed developed a wobble at +60 over the speed limit and i had to slow down due to the insistance of the wobble when holding that speed for a sustained period.... 30 seconds or more .... and no the wobble does not disappear with a faster speed ...... OMG i am NEVER going togo that fast ever ever again! ! :cop :law :spank
So any words of mechanical wisdom or links to previous discussions would be great .
And no I wont go that fast again as my licence and desire to ride really are more important than stupid speeds.
:bl11
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Definitely not a characteristic of the ST1100. I'd say the suspension is overdue for an overhaul to solve the cornering wobbles.
High speed wobbles are usually aerodynamic, but you could check the head bearing.
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Hi Spanner,
I think all the wobbles are related to each other in your case. Not many other 1100 pilots have ever complained of this problem.
I'd suggest looking at your fork alignment/steering head bearings, as you have reported wobbles at quite low speeds. I'm certain that if all your wear tolerances were at factory 'new' specs, you would not experience this. See if you can detect 'play/movement' indicating wear.
Is the wear on your hoops even as well?
Most of us can let go of the handlebars and the bike will track fairly true in most cases. It sounds like yours won't do this.
Hope this helps.
Cheers, Diesel
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Perhaps adding to what had already been said, I'd check the following:
Wheel balance
Wheel bearings, front and back
Head bearings
Swingarm bearings
Rear shock and bushes.
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When i let go of the bars it definitely does NOT track true ..... wants to go to the right.
i need to lean over to the left a LOT!
what are the hoops? Brake disks??
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Where front forks aligned properly after being removed for any reason e.g. fork seal replacement.
Hoops = tyres
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If the bike is pulling to the right, then the front wheel either hasnt been fitted correctly, or the forks are slightly bent.
I have had my 1100 a bit faster than yours ( quite some years ago) and it was solid as a rock.
Wobble in a left corner could mean the left shock isnt quite up to spec. You may also have the rear spring set too soft, as that will generate a seesaw effect at times, and at high speed.
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Thanks all.
How to you tell if the forks are not right?
i will definitely go get the wheel balance checked.
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Definitely should the doing that at such low speed. I've towed a trailer at 160+ with no signs of a wobble. Straight line solo speed I've gone significantly faster. I hate the fact that we now have speed limits :cuss
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Mine couldn't track true when I got it, measured the top of front forks and one of them, forget which was around 5mm lower than the other, after loosening the clamp and evening up it solved the problem.
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Really hard to tell what is up remotely. Basically you would need to go through all the suggestions one by one. What age and how far has the bike gone? Tyre pressures and wear pattern on the tyres can give clues (what tyres are they?) Making sure the front wheel has been put back in properly, and the wheel bearings are ok. Fork springs may be sagging if original, and fork oil needs changing and setting up right. Might be wear in the fork bushes. Rear shock may not be working properly. Steering head bearings can get notchy, and if loose or over tightened can do funny things.
Your bike may be a good example to use at a maintenance day to check out the basics at least.
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For my 2 bobs worth,, this is ex "Blue Honda`s" St . As Ive read in many places on the forum, that he kept his bike in pristine condition. so this isn't making any sense. My first port of call would be condition of tyres and pressure seeing as it was sitting for a while. As basic as that sounds, but I would also have a mechanic look at it before you ride it again. Good Luck,................................ :wht11
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If that is Brad's ex bike, then it would be in good condition. In that case tyres and tyre pressures would be the first thing. Tyres may have gone a bit hard. But well worth a good look over the basics just in case.
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I used to run about 5psi extra in my tyres than what the book said. Made for rock steady tracking on the road.
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Issue is fixed!
today i learnt about trusting servo tyre preasure gauges :fp :well and also aerodynamics. :think1
My tyres were low even though the servo said thay were fine. I went out and bought a basic tyre preasure guage and checked it ..... was only 31 psi!
The other issue was basic aerodynamics! I realised now looking back at a photo that i had a small ukulele in a case strapped to the left hand side of the rear pannier .... me thinks that when going FAST the airflow differential would cause the bike to start to wobble.
i fixed the tyre preasure today and had no weight or other protubernces on the STeed and gave it what for on a very seculedstraight road today...... no wobbles. Also no left hand turn wobbles and no low speed wobbles.
Lesson well learnt.
thanks for all your ideas and help.
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That's great news Spanner, and a lesson for ałl of us to be vigilant with tyre pressures. 31psi on an ST is a flat tyre! Thanks for sharig the solution.