imported post
Redwing is right. Two things:
#1. Fire any mechanic that does not use computer spin balancing. Bubble balance is OK for a dirt bike but there is too much rotating mass in these wheels for that nonsense. A slight out-of- balance that cannt be detected by a bubble balancer will wreak havoc when that massive wheel starts spinning.
#2 Had same thing happen with brandy-new Dunlop. Wouldnt balance and gyrated when running. Put a straight edge on the tread and found the tread deflecting when it rotated. Cause? Defective tire. Large crack inside tire casing. Dunlop sales admitted to tire problems in that cheap series. Replaced with a good Bridgestone and spin balance - perfect.
1800 should be too new to have developed front-end problems.
Dont buy the tale about loose head bearings, they cannot cause it, only amplify whats there. The inertia in that 50 lb (?) wheel rotating at several hundred RPM is far more than what input a loose head bearing can cause. Remember the old science demo about holding a rotating bicycle wheel over your head? The 10 pound wheel will drive your 100 lb body wherever it wants and theres nothing you can do to stop it.
Tightening the head bearings (from an engineering standpoint) does something called "damping an oscillating system". The "oscillation" is the handlebars going back 'n forth and "damping" is tightening the bearings to "dampen" or stop the vibration. Find a vibrating radio antenna on a car or bike thats vibrating and pinch it with your fingers - the vibration stops or changes radically.
Tightening the bearings
cannot possibly eliminate a problem in the front wheel, the vibration is stil there, but now the bearings absord the vibration and destroys the bearing races. Then one day you wake up with handlebar shake you cant control and go in the ditch. BEEN THERE, SEEN THAT! Its
extremely scary.
I decided to test this theoryon my first GL1200A (and have done it on every vehicle since). I set the head bearingsextremely loose. Hondas test at the time was to put the bike on main stand, lift the front wheel, center the bars and then push them to one side, they should not hit the stop. Second part of the test was that the handlebars should not shake when held with 2 fingers of each hand. Mine head bearings were so loose they hit the steering stop and went half-way back to center.
There was
absolutely no shake in my front end at ANY speed up to 110 mph with no hands on the handlebars. Made for extremely fast steering butI dont recommend it to just any rider. Throwing 940 pounds of Gl1200 around isn't easy.
Dave
http://gl1200harness.tripod.com