ST1100 low speed wobble

Hi all and thanks for viewing my post. I have just bought an ST1100 (first time after years of sports tourers). The bike is in very good shape, never crashed or thrashed. At the risk of upsetting folks who have answered this question before does any know why it wobbles between 20 and 40 MPH? The wobble isnt so bad you cant ride it just mostly annoying. If I take my hand of the bars sometimes it feels like it is going to start tank slapping (I did this for testing purposes only). Somtimes it doesnt seem to do it at all. A friend of mine had an ST1100 and it did exactly the same thing. After changing pretty much the whole front end of the bike it was still wobbling. It currently has a pretty worn set of BT020's fitted. I have ordered a new set of tyres which arrive tomorrow. BT020 for the front but it seems they couldnt get a BT020 for the rear because it has been superseded by the BT021 so a BT021 for the rear. Is there anything I need to tell the local shop about fitting them? Thanks, Ian.

Mine did that and I replaced the head bearings with tapered roller bearings instead of the OEM ball bearings. Problem solved.

Could also be the tire pressure, but sounds like you've checked that already. The worn tires definitely aren't helping. Be interesting to see how you get on after the tire change.

I had an 1100 that did that too, though it was at a higher speed, around 40 to 50 mph. I don't know if the bike had ever been damaged, but was assured by my dealer it hadn't. I tried the obvious stuff, tyres, pressure, then traded it for a 1300. Problem fixed. But it was the only one of three I owned that gave any problem at all.
I find that with my current 1100, road paint & grooves in the tarmac pull the wheels something terrible when the tyre is getting near the wear indicators.
A tyre rep at a recent forum demonstrated that tyres are actually worn out before they hit the tyre wear indicator, this being a legal thingy rather than a real life thingy.

How many miles on the bike?

Worn tires will cause it... I have Avons on mine right now and it doesn't have any head shake; but, I have also replaced the head bearings with tapered... at about 55,000 miles.

Mark

TIRES!!

Tires is a good place to start. After all you said they are worn. As others mentioned head bearings would be another thing to try but I would do one thing at a time and start with the tires.
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I had Dunlops that were so bad I went into a "Death Wobble" if I tried taking my hands off the bars. I thought for sure I had to do the tapered head brearing fix, but when I switched to Metzlers, I could ride no hands smoothly !

Steering bearings and/or front springs fixed my low speed wobble. I don't know which one fixed it since I did them both at the same time.

Tires.

Avon Azarro front tire was smooth, no problem.
Avon Storm gave mine the head shake. One tire from the beginning, the next tire only after wearing a few thousand miles.

I have Sonic front springs and tapered head bearings.

Try the wheel installation guide on the words of wisdom list. Might be the problem too. I just replaced the forks on mine and had a wobble after installation. Ended up smooth as butter after following the guide.

New tires can mask the problem, but tires are NOT the cause. Incorrect wheel alignment is the cause and is something that I bet less than .01% of you who are having problems have checked.

Thanks everyone, I have had word with the local dealer and they are fitting new BT021's front and rear tomorrow. I told them about the wobble and they seem to think it will be mostly caused by worn tyres/balancing. The bike has done 50k miles. Hawkeye do you mean the rear wheel alignment? If so i will get them to do that too.

nobby8 said:

Hawkeye do you mean the rear wheel alignment? If so i will get them to do that too.

Click to expand...

On most motorcycles front and rear wheels need to be in alignment with each other. Here is the poor man's way:

http://www.ktm950.info/how/chassis/Chassis_basics.html

I replaced the steering head ball bearings with tapered roller bearings on my '93. Problem (to the extent it was a problem) solved.

thanks for all your replies! I had the tyres changed today (new BT021's) and the the mechanic checked the headstock and wheel alignment too. It rides perfectly so I guess it was either the tyres/wheel alignment.

Looking forward to many miles of wobble free riding!

Whooo Hoooo
Now get up there and rack up some miles!!!!!

Interesting to note that all the actions that have reportedly "cured" the wobble problem involved doing something that would have removed and re-installed the front wheel and then presumably doing the standard alignment procedure of leaving the pinch bolts and the axle nut slightly loose, bouncing the bike on the front wheel with the brake locked several times and then tightening every thing to spec.

Is the actual cure then just the alignment procedure as mentioned by Rob Parker (HawkeyeST) or the combination or result of several procedures? And were bikes that begin to wobble with a new tire not aligned properly after that install? (allowing for the fact that a bad tire is certainly possible).

Perhaps somebody experiencing "the wobble" could try the alignment procedure first BEFORE going to the extent of changing out the bearings or installing/replacing a tire and report back? Especially if you have just replaced a front tire. It might provide valuable info for the group?

Jerry
1996 ST1100
1987 Kaw 88SE B-1

I have a similar problem with my ST1100 if I run any less than 39 PSI in the front tire. It gets worse as the front tire wears. If I remove my hands from the handlebars while decelerating, the front end begins to wobble.
I find the easiest solution is to just not remove my hands from the handlebars when I brake to a stop and that solves the issue for me each and every time.

I don't know if it is as simple as one problem, as mine (96 ST11 police model) has never had the wobble, even with well worn tyres, tyre pressures on the low side and notchy steering head bearings (they were taper bearings). Some do wobble, some don't.

saaz said:

I don't know if it is as simple as one problem, as mine (96 ST11 police model) has never had the wobble, even with well worn tyres, tyre pressures on the low side and notchy steering head bearings (they were taper bearings). Some do wobble, some don't.

Click to expand...

Mine didn't with Excedras and immediately did with Storms (even the replacement front they sent me). New rear is going on next week. Who knows, maybe that'll fix it...