wobbly steering almost a full on tank slapper.

[BaldBaBoon]

93 R100 GSPD


My bike gets a right wobble on when out on the roads, its been a problem that must have been slowly creeping up.....buts its at a stage that I cannot ignore it anymore.

Symptons.

1) When coming off the throttle at about 30 + mph the front starts to go into a slow weave/wobble and sometimes just shy of a full on tankslapper.

2) During normal riding,constant speed....if you remove one hand from the bars....the same starts again.

3) Higher speeds ( 80MPH ) you again get a quite impressive wobble on.

Weird Symptons

1) No panniers and rack fitted and a full tank of fuel....the wobble is hardly noticeable.

2) Panniers/rack fitted, or weight put on rear.....it turns into a comedy clown bike.

Things checked

I have checked the wheels/spokes for damage and both tyres are new and normal pressure.

Headstock/steering bearings appear perfect...no tight spots, just smooth and no movement.

Rear suspension appears fine, no wear on any mountings and damping/rebound/compression works normal.

Checked around bike for anything obviously loose or missing.....nothing found.


Shall I get myself down the gym and grow some bigger muscles and man up or is there something cunning that I have not checked?

 

[Beemerboff]

You havent specifically mentioned the bearings at the rear of the paralever, which can give similar symptoms.

And tire profile , the flater the profile the more shake.

The head bearings might be a bit loose too, I like a little preload on them, same with the bearings at the front of the paralever.

However ,it is possible to overtighten all of these bearings, so might be better to have someone with a bit experience to show you the ropes the first time.

 

[DrFarkoff]

Head bearings If they are brinneled (straight line marks on casings) they will have tiny little grooves that will scare the Keek outta

So Slip them a part check them and they are nice and clear Apply fresh grease to them

Then when you're rebuilding nip em up and the trick is just tight enough that when you touch the handlebar that they fall to the side with a little drag and not slam one side or other quickly

Good Luck

 

[DevonianScotsman]

Spindle bearings on the front wheel perhaps? If they are loose, notchy or collapsing then you will notice a gentle weave to start with - getting worse until the bearing fails and the wheel touches the fork and the brake disk jams in the caliper. Which of course is fairly fatal.

Good luck, I hope it is sorted soon.

Jonesybop

 

[Steptoe]

That'll be your head bearings being just a touch too loose. And i do mean "just a touch".

 

[mikyh]

never had one

But read a lot about it.
It's a little like learning swimming from a book, but usually wobbles are created at the back, not the front. Check there first.

 

[DrFarkoff]

So Slip them a part check them and they are nice and clear Apply fresh grease to them

Oops If you have heavy vertical lines replace the bearings! Remember when ordering to get the stupid alloy plate below the lower bearing!

 

[BaldBaBoon]

Thanks for the info....looks like I got some work to do at the weekend.

I might even have to adjust my rear shock as I appeared to have put quite a lot of " muscle " on recently...ahem.

 

[(RIP) pastyman]

Sounds like a case of "wobble and weave". Release the pressure on the bars as you slow down and you will get low speed wobble. Easily rectified by holding the bars firmly. High speed weave is different and can be caused by head bearings as have been described but it can also be caused by worn tyres, especially the rear, worn shocker and the presence of top box or panniers can also not help. Dont know what you weigh but lighter riders will suffer more.
Just as an interest I have a video of some teste done in the 70.s on a range of bikes with two riders of differeing weights by the transport research lab.
I would but it on hear but dont know how. It is a very interesting and frightening bit of film though the video is a bit poor quality. If anyone can download it onto here I would gladly send a copy.
"

 

[cobbster]

Wobbly PD

Thanks for info on this thread, I have been having issues with my PD wobbling and weaving. The first time it happened I was on a motorway @70ish, the front wheel, handle bars to start with, followed by the rear and the whole bike. (Panniers and top box were fitted with very little weight in them) I thought I might end up coming off, very uncomfortable.
My initial thoughts were a puncture in my rear tyre, having got to the hard shoulder from middle lane, but it was still up, later I found the tyre pressures were a little low.
I also thought that having pumped up the tyres things would be fine; however it has happened again (without panniers and top box) at the same sort of speeds.
My handle bars did fall to the right hand side and hit the stop, on the centre stand and front wheel in the air.
I took the front forks off yesterday to inspect the head bearings; they are OK in my book. Cleaned them of the old grease and applied new grease and assembled. I tightened the steering to the point it now slowly bumps the right hand side stop. The steering now feels firm but loose (if that makes sense).
Took the bike for a little run this morning (without panniers and top box) on twisty roads and dual carriage way. The bike does feel more planted than before and so far is good. I will have to put panniers, load up and every other combination to further test, but for sure I feel better for doing this exercise and hopefully so does my bike.

Thanks again

Cobbster

 

[Kenny]

Headstock bearings loose..or you have the dreaded TKC80's fitted !!

Oh and keep both hands on the steering at all times !!