all speed wobble

I got some wobble issues on my '79 650. When ever I take one hand of the handle bars I notice a wobble at pretty much all speeds, but it's actually the worst at about 45mph. And it also wobbles a bit every time I hit a little bump. I REALLY need to fix this, but I'm not sure where to start.

Should I start w/ a fork rebuild, tapered stem bearings, or new wheel bearings??

(By the way I put in new rear wheel bearings and swingarm bearings during my restoration project, but the stem bearings and front wheel bearings looked good so I didn't mess with them.)

I wonder sometimes if I didn't get the forks clamped in at the same height, they look like they are in exactly the same position, but I didn't verify that with an accurate measurement.

thanks for your help

Is your front wheel straight/round? Put the bike on the centerstand and see if the wheel bearings are loose.....chris3

The PO had installed tapered steering bearings. My bike will not twitch even if I drive one handed and try shaking the handle grip with it... OK, maybe I don't try this at 120 Kph and that's probably why I'm still here to tell the tale.

However, I do keep them screwed down a little on the tight side.

Hope that helps.

Best of success.

I would check the front wheel runout first, they are not known the be perfect as are the steering heads not quite inline with the frames. In other words some of them dont track right with the back wheel following the front. The very first Z1's run at Bonneville had to be put on a frame rack and the steering heads cutoff, realined and welded back on or they were unrideable at speed. A guy I know was involved in this deal. Some are a lot better then others, they werent precision made machines. Leaning forward on the bike can help you come out of a wobble on one piece, still going to be scary. It also may be as simple as loose steering head bearings too or the races not seated all the way because of paint or dirt

Speed wobbles can be a real PITA* to isolate/fix. The short list goes like this:
1.Swingarm bushings/bearings worn out.
2.Front tire developing "Cupping" of the tread.
3.As mentioned Steering head bearings worn.
4.Unknown frame damage from being "Dropped"
5.Rear shock hardware loose
6.Rear shocks worn out.

*Pain in the @ss

MFOLKS Excuse me, but what is "cupping of the tread".
Yep, born stoopid:woohoo: :woohoo:

Some front tires will cup from out of balance or other issues. Kind of looks like someone took a half spoonfull of rubber off the tire. Raising or lowering the forks in the trees shouldnt do it either. Did this bike just start this or did you buy it this way? Almost sounds like its been wrecked before

mtkawboy, thankyou:)
The things I learn on 'ere!

but the stem bearings and front wheel bearings looked good so I didn't mess with them

Stem bearings (bottom and top) for sure... Go tappered!
Insure all triple tree/clamp and steering head bolts are torqued down to specifications.

For testing, raise the front end off the ground (jack under middle chassis). Rotate bars slowly, smooth or friction rotations... Shake forks back and forth, tight or sloppy with play... Are you seeing the steering stem wiggle inside the neck... Spin the wheel and watch it's rotation, is it straight or wobbly. In putting side pressure on wheel, is it tight or wobbly... There's a whole slew of things to look at..

For a little additional costs and piece of mind, replace those wheel bearings as well.

Just my two cents worth...

OMR

I personally have never seen a used set of steering head ball bearings that were any good since theres no way to lube them after they are installed. Put the tapered ones in and drill and tap the steering head for a grease fitting.

mtkawboy, never thought of adding grease fittings there... good stuff.

Do you have a pictures of your install?

Any does and do'nts you came accross? Any prefered locations?

Thanks.