Pretty wild shimmy at 37

MJR · #1 06-30-2008, 10:36 PM

miles per hour.&nbsp\\; The bike just started doing this.&nbsp\\; If I loosely hold the bars when I decel from just over 40 it starts to shimmy pretty bad at about 37.&nbsp\\; If I grip the bars firmly it doesn't seem to shimmy.&nbsp\\; I checked the tires they were both up at 36 pounds.&nbsp\\; I put it on the lift and did the steering head bearing&nbsp\\;swing-by test, seems right by the manual.&nbsp\\; I was thinking maybe the motor mount?&nbsp\\; What do you think?

bagman1 · #2 06-30-2008, 10:40 PM

Head bearings garenteed. Mine did it when new, took it to the dealer and it took them 3x to adjust it so it would stop .

dougbk · #3 06-30-2008, 10:44 PM

Front tire wear.&nbsp\\; When Dunlops get to a certain wear point they will start cupping slightly on the edges and that can cause it.&nbsp\\; I have had that problem in the past.

MJR · #4 06-30-2008, 11:11 PM

Well I'll have to bring it in to the harley shop if it's head bearings, I have no experience with adjusting the head bearing.
The tires seem fine, no cupping or visual flaws, not too many miles on it, about 6000, seems like plenty of tread left.
Funny it seems only to happen at 37 mph??
Thanks,
Mike

Mississippi Bagger · #5 06-30-2008, 11:57 PM

Could be the front wheel bearings also.

RoadKingCop · #6 07-01-2008, 12:21 AM

My FJR1300 would shimmy at about the same speed.&nbsp\\; It would also do it at about 70mph and 15mph. Every time I doubled or cut the 35mph speed in half, the handlebar would shake side to side.&nbsp\\; Turned out that Yamaha but a tire that was "out of round" up front.&nbsp\\; They were Metzler MEZ-4's.&nbsp\\; It was a bad front tire.&nbsp\\; Might want to look into that.

Ben

KraZeeInOhio · #7 07-01-2008, 04:19 AM

I had the exact same problem last fall during a road trip to San Diego.&nbsp\\; The dealer tried everything (neck bearing, swing arm pivot bearing, swapping the front &amp\\; rear wheel/tires, etc.) and nothing fixed it.&nbsp\\; They were able to get the HD Factory Rep to look at it after a few days and he had them change the motor mounts which helped, but the final fix was replacing the front tire.&nbsp\\; Here's the link to my original thread from last October http://www.hdforums.com/m_2323227/mp...tm.htm#2323227

drbillk · #8 07-01-2008, 09:12 AM

I've seen something as simple as low air pressure in the tire cause this too.

MJR · #9 07-02-2008, 12:38 PM

Talked to my mechanic.&nbsp\\; He like Bagman1 is convinced it is theSteering head bearings.&nbsp\\; He thinks I can do the adjustment.
Does anyone know what size socket I need for the fork stem nut?&nbsp\\; I am guessing it is 1 1/2.&nbsp\\; Has anyone else made this adjustment?&nbsp\\; I am thinking I should not have to&nbsp\\;move the bearing adjuster, only tighten the stem nut.&nbsp\\; Does that sound right?
Thanks, Mike

gilbos440rt · #10 07-02-2008, 04:53 PM

You'll have to move the adjuster to tighten your bearing's, try 1 notch to start with, the main nut might be a little loose I seen guy's here on the forum have that problem. My Road Glide just started doing the same thing, use to ride home with no hands for miles at a time ( deserted country roads ) but it started the shimming, I checked the main streering nut but it was fine, I'm thinking it's the front tire on mine 18000 miles still some tread left though

&nbsp\\;I'll try a new tire then the bearing adjustment. Good Luck, you can do it yourself I'm sure