Wiggle at 70 mph

[bransan]

With just over 32,000 mi, on My 04' R1150R I am starting to notice a slight wiggle. I just installed new tires at about 2000 mi intervals, first the rear then the front. I was noticing it a little before the tire changes. Is there a steering stabilizer application for this bike? Could it be the swingarm bearings? I have installed new bearings at the final drive to rear swingarm attachment, because one was bad. I never noticed any play and still can't find any lateral play at the swingarm. Could it be in the steering head? Could it be improper tire inflation? All suggestions welcome.

[Byrdguy]

There is no adjustment on the steering head bearing. It is a sealed double row bearing and, if it is worn, must be replaced. Check the ball joint on the front telelever. Pop the plastic caps off the top of the fork bridge where the fork legs attach and look at the bushings. They are rubber and steel. Make sure they aren't worn or distorted. Definitely get the tires to the recommended PSI.

[riceburner]

Check the pressures first.

Check the bearings for play.

I'd recommend adding a touch of preload to the rear suspension - seems to help, especially since BMW supply the bikes very "laid back" on this setting.

[Boxer]

Ride at 65 or 75.

[FloridaBeakster]

A high speed wobble is not to be taken lightly and this could potentially be an indicator of serious problems to follow.

Read this article on how to test for wobbles, but be EXTREMELY CAREFUL and follow it at your own risk:

http://w6rec.com/duane/bmw/wobbles.htm

I never tried the procedure while standing on the pegs. If it's stable at higher speeds with me sitting with a good whack on the bars, it's good enough for me. It doesn't tell you where to look for the problem, but does tell you if there is a problem or not and if you fixed it or not. I've sorted a couple of bikes out using this test procedure.

[MikeCam]

Check that you properly shimmed the bearing replacement.
Check for front and rear runout. Confirm that the front wheel axle is properly aligned in the forks - owner's manual shows procedure. Check for proper seating of the rear hub and re-torque lugs.
Check rotors for true. Pads for drag.
Try to pin the conditions: same road, same speed, same wind, same baggage loads. Is there a new road surface where you notice this most? Have you changed your bags, loads, configuration, tank bag,
New handlebars, risers? New windscreen?

[bikermeow]

are you tyres balanced? i mean weights installed to balance it out?

Cheers

Cat

[bransan]

I have the proper shims installed. Yes the tyres( tires) are balanced, via computer spin balancer. I will check the front end alignment, sounds the most likely scenario. I've noticed it on several different road surfaces, and different types of baggage loads. Most noticeable with no extra load just Me and the bike. I appreciate all the good suggestions. I'll let you know what I come up with.

[KHaynes]

The first thing is to set the tyre pressures correctly. This is an easy thing to do.
Then.... take the advice of Riceburner and try some different preload settings. This will change the rake angle and amount of trail. The resulting change in geometry could solve the problem completely if it is like "speed-wobble".
If the wiggle occurs "every time" and "all the time" that you go at 70mph, then I would not discount a balance problem even though they have been balanced. The wiggle could also be caused by a bulge in the sidewall or an out-of-round tyre.