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Help! 1979 Bonneville wiggles on interstate above 65MPH

Posted: Thu Jun 02, 2005 7:40 am
by jaurph
Hi All,
My Bonne has taken on a wiggle at speeds above 65. It's not a shutter like you'd have with a car that needed aligned. I have checked: tire pressure front and back, rear axle placement, neck and front wheel bearing play. The only thing I found was the rear axle needed adjusted b/c one side was about 1/2" further back than the other. After adjusting the axle I took it for a ride. Everything felt fine until I was at 70mph where it wiggled again but not as pronounced. So could it be the front wheel is unbalanced or the tires have developed flat spots? Lastly I have Dunlop tires on and I was wondering if another brand with a softer compound may improve the wiggle or the overall highspeed "comfort".
Thanks in advance, Jim

Posted: Thu Jun 02, 2005 12:29 pm
by Gummiente
Other than balancing the tires and making sure all the spokes are tight and the wheels are running true, you should check the swingarm pivot bushings and the steering head bearings for wear.

Posted: Fri Jun 03, 2005 1:45 am
by JCS
Another question. How much wear do you have on the tires? If the rear is wearing flat in the middle this could cause your wiggle. A softer compound will not cure your problem. New tires might. Also do you have a windshield or luggage on the bike? These have also been known to induce wiggles.

Update

Posted: Sun Jun 05, 2005 1:11 pm
by jaurph
Hi,
The tires are hardly worn but not sure how old.and I'm going to have them balanced tommorow and test them. I also have a windshield on the bike so I'm going to remove it also. Thanks guy. Jim

Posted: Fri Jun 10, 2005 11:24 am
by Cockney Rebel
Hi Jaurph.
Has your bike got a steering damper on it ? when I used to race Triumphs they had a damper which was slack at slow speeds and would be tightened up for high speed , a speed wobble often happened at around 65mph on some bikes without a damper, if possible I would blast through the wobble until it got smooth again.
Smudge

bike wiggles above 65mph

Posted: Mon Jul 04, 2005 8:42 am
by twowheelindave
Bad bearing, bent rim, wheel out of true, wheel need balanced, triple tree loose, wrong tire pressure.

Good Luck