2009 Street Glide with 21inch rims wobbles at speeds around 80 mph

[LeV37]

Greeting HOG riders,

I am new to this forum and own a 09 street glide that i recently just got customized. The bike looks awesome, the problem I have is that at speeds above around 80 mph the bike begins to wobble back and forth. Any suggestions, ideas, to eliminate this problem. I really like to stretch the bike out on long strips of interstate late at night and this is killing me! Thanks for the help.

 

[HDDon]

Did the bike wobble at this speed before you did the wheel mods? What other mods have you done or had done? Welcome to the forum.

 

[LeV37]

I added a 21 inch rim and tires to the front and 18 inch rim and tires on the rear. One rotor was removed and chrome forks were added. ABS disabled, of course. Hand grips, throttle, clutch, brake and throttle cables were also chromed out. Control buttons chromed And Paint.

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Thanks. No the bike did not wobble at all before. I had it up to 120 with no wobble, just a fast smooth ride. These conditions changed after modification.

 

[HDDon]

In the self help section there is a section dealing with wheel alignment, you might start there. Did you have the wheels high speed balanced or just static balance? When you replaced the forks did you check the steering head buy doing the fall away test? Do you have any vibration before you hit 70 or 80mph?

 

[jdaws]

I would suspect a wheel/tire imbalance since they are new. Have you contacted the shop that did the mods?

 

[LeV37]

I have done none of the above. Thats what I am here for, asking suggestions and why. I have a friend that says its the high wind and because the bike is lighter with the new rimes and tires. Is that a possibility? Its not a vibration, its a wobble, like it shakes back and forth a flowing side to side motion. It only does it when you get up to around 80, maybe the wind generated at that speed is a factor, but I dont like the ride like that.

 

[HDDon]

I don't think this is a wind problem, and since it was not there before the rim/tire change this is where I would start looking. If you have a way to lift the front tire off the ground, try spinning the tire and see if the rim is stright. It could be that the tire was not mounted correctly and the bead is not seated to the rim. It may be that the spacers were installed incorrectly and the front and rear tire are not in alignment.

 

[89 FXRS]

if it started right after the modifications it would be a great chance that the wheels/tires have something to do with it. Also - check the tire pressure on both the front and rear as well as the air pressure on the shocks - fxrs

 

[ppofootball]

Hey Lev,

I did the same mods but kept my ABS of course this has nothing to do with your wobble. You will feel lighter going from your 16 to the 21 as I did going from the stock 18 to a 21. They balanced my rims with the dyna bead and sometimes its hard to get correct unless the guy who did your rims did a bunch of them. I had mine done in Daytona last year Bike week by the RC Component guys who had done 100 bikes prior to me.

Another important factor TIRE PRESSURE..On Metzlers 21" their sidewalls are softer you should go 2psi higher than rating cold. Avon tires have a stiffer wall rating..Go to the Metzler website for inflation procedures
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Keep in mind, its a touring bike and engineered and tested with the stock rims, tires ,etc... I can feel it shimmer a little at about 85 but again, lot of factors beside the 21" rim, ( road conditions, Wind, Weight etc...)

If its a bad wobble, have the guy re-balance your bike and ride it at several speeds ( 65mph for 1 minute ), 70 for another and so on. Go past the wobble point. IF it still wobbles at higher speeds than 80 than I think your balance is off. .

Hope this helps brother..

 

[LeV37]

Update....I took the bike to the local harley dealership and they said my tire air pressure was off. They made adjustments. I took the bike out and it still wobbles, but now at a higher speed, 85-90 now. I took the bike to another harley dealership and he said that the metzler tire is not strong enough to handle a 900 pound bike, it is only 2 ply. He recommends changing rear tires. I am going to put my friends avon 200/18 rear tire on to see if i feel a difference. I will update.