Higher Speed Wobble Problems

texasdynaryder · Oct 6th, 2009, 11:01 AM

im am owner of a 07 dyna street bob. this is my second bike and i love upgrades and looking diff. but...
6 months ago i installed an Accutronix Wide Glide Conversion kit with a 3 degree built in rake... nothing fancy had those powder cated.. had both wheels torn down ( to have hubs and rims powder coated) and relaced. an 1inch lowering kit in the back to bring the trail and drag back to normal. once back together it has an awful wobble above 65 to 75 MPH. the bike has been in 2 seperate HD dealerships where nothing could be found wrong. and its 10 k service. if anybody has as suggestions i am ALL ears. thanks

Hoople · Oct 6th, 2009, 12:45 PM

Tex,
Do you still have the same stock tire sizes on the Bike. If not what sizes are they.

From where I am it Sounds like you have a Dynamic imbalance (2 Plane imbalance) in one of the tires. This type of imbalance can Not be detected in a simple bubble balance procedure. Suspending the tire on a knife edge and finding the heavy point by gravity will NOT correct a 2 plane dynamic imbalance.

A rotating mass that has a static imbalance (bubble balance) will have a "Tramp" or a vertical up-down imbalance. A rotating mass that has a dynamic 2 plane imbalance will have a "Wiggle" or a dynamic imbalance.

What size rear tire are you running. Did you make ALL the modes at the same time.
I certainly can be wrong but if I was to have only 1 guess as to what it was, without seeing the bike & without being able to test a few things or ride it, I would say it is a problem in the re-lacing of 1 of the wheels. The reason I say this is because a 2 plane imbalance will manifest itself at a specific resonant frequency (narrow band of RPM or MPH) which is exactly what you have.

Hoop!

springer03 · Oct 6th, 2009, 12:53 PM

really sounds like front to rear alignment.. Low speeds you compensate. Tires will probably wear on one side.

texasdynaryder · Oct 6th, 2009, 06:19 PM

they should be stock size Metzler Me 880 but will check for sure when at hope.... as far as alignment. they seem to be wearing pretty evenly?!? and yes all MODs were at the same time.

Hobbit · Oct 6th, 2009, 07:14 PM

you will get a certain amount of wobble as you have lengthened the wheel base of the bike, you may have also affected the front end trail despite lowering it at the rear to compensate but you will have most deffinately lengthened it making weave at speed

texasdynaryder · Oct 7th, 2009, 04:27 PM

Front tire is a 100-90-19 57h
Rear tire is a 190-70-b17 73h
both of which are tubeless. now another question of mine would be can a spoke rim be
balanced and still be untrue? or if thats even possible. gonna try and get some pictures posted today of other possble questions.

Hoople · Oct 7th, 2009, 04:40 PM

Quote:

Originally Posted by texasdynaryder

now another question of mine would be can a spoke rim be
balanced and still be untrue?

Absolutely. You can bubble balance a tire and rim that was in the shape of an Egg. The balancer is blind and is only telling you where the heavy spot is.

This is Especially true if you only Static (knife edge/bubble balance) balanced your rims/tires.

What I would do is lift the bike so both wheels are off the ground. Rig up a fixed metal pointer to you can check BOTH vertical and lateral run out. Of course it is only a rough check but you at least will see a bad case of run-out which you could easily have.

Hoop!

Not that it has anything to do with your problem... I though all laced rims needed Tubes. ?? I did not know you could have adjustable spokes and be tubeless.

Hoop!

texasdynaryder · Oct 7th, 2009, 05:56 PM

I also thought the same also! if u get time check the pictures that were just uplaoded and check out the front end. the kit came with an aftermarket axle. if looking in the dyna service manual it requires a 7/16 drill bit to fit through the axle tension hole. then butted up against the lower fok tube. my after market axle still has probably near a 1/4 inch to go... and as far as the front rim goes to be centered within the forks. is there any off-set in the front rim?

Hoople · Oct 7th, 2009, 10:04 PM

My guess is you must have Tubeless tires with tubes in them. There is nothing wrong with that..

Don't see any uploaded pictures..

Hoop!

texasdynaryder · Oct 8th, 2009, 11:41 AM

they are on my profile

Oct 6th, 2009, 11:01 AM	#1
texasdynaryder New Family Ride: 2007 Dyna Street Bob FXDB Join Date: Oct 4th, 2009 Location: Paris, Texas Posts: 8	Higher Speed Wobble Problems im am owner of a 07 dyna street bob. this is my second bike and i love upgrades and looking diff. but... 6 months ago i installed an Accutronix Wide Glide Conversion kit with a 3 degree built in rake... nothing fancy had those powder cated.. had both wheels torn down ( to have hubs and rims powder coated) and relaced. an 1inch lowering kit in the back to bring the trail and drag back to normal. once back together it has an awful wobble above 65 to 75 MPH. the bike has been in 2 seperate HD dealerships where nothing could be found wrong. and its 10 k service. if anybody has as suggestions i am ALL ears. thanks

Oct 6th, 2009, 12:45 PM	#2
Hoople Contributor$ Ride: 2009 Dyna Low Join Date: Aug 16th, 2009 Posts: 506	Re: Higher Speed Wobble Problems Tex, Do you still have the same stock tire sizes on the Bike. If not what sizes are they. From where I am it Sounds like you have a Dynamic imbalance (2 Plane imbalance) in one of the tires. This type of imbalance can Not be detected in a simple bubble balance procedure. Suspending the tire on a knife edge and finding the heavy point by gravity will NOT correct a 2 plane dynamic imbalance. A rotating mass that has a static imbalance (bubble balance) will have a "Tramp" or a vertical up-down imbalance. A rotating mass that has a dynamic 2 plane imbalance will have a "Wiggle" or a dynamic imbalance. What size rear tire are you running. Did you make ALL the modes at the same time. I certainly can be wrong but if I was to have only 1 guess as to what it was, without seeing the bike & without being able to test a few things or ride it, I would say it is a problem in the re-lacing of 1 of the wheels. The reason I say this is because a 2 plane imbalance will manifest itself at a specific resonant frequency (narrow band of RPM or MPH) which is exactly what you have. Hoop!

Oct 6th, 2009, 12:53 PM	#3
springer03 Play The Throttle Ride: 2003 FLSTSI Join Date: Sep 8th, 2009 Location: Alabama Posts: 167 My Mood:	Re: Higher Speed Wobble Problems really sounds like front to rear alignment.. Low speeds you compensate. Tires will probably wear on one side.

Oct 6th, 2009, 06:19 PM	#4
texasdynaryder New Family Ride: 2007 Dyna Street Bob FXDB Join Date: Oct 4th, 2009 Location: Paris, Texas Posts: 8	Re: Higher Speed Wobble Problems they should be stock size Metzler Me 880 but will check for sure when at hope.... as far as alignment. they seem to be wearing pretty evenly?!? and yes all MODs were at the same time. Last edited by texasdynaryder; Oct 6th, 2009 at 06:24 PM.

Oct 6th, 2009, 07:14 PM	#5
Hobbit Moderators Ride: 2009 FAST 103 Street Bob Join Date: May 18th, 2007 Location: The Shires UK Posts: 7,625 My Mood:	Re: Higher Speed Wobble Problems you will get a certain amount of wobble as you have lengthened the wheel base of the bike, you may have also affected the front end trail despite lowering it at the rear to compensate but you will have most deffinately lengthened it making weave at speed __________________ Please stop by the "self help section" for maintenance tips, diagnostic codes and much more. >>Self Help Information and Tips<< click me!

Oct 7th, 2009, 04:27 PM	#6
texasdynaryder New Family Ride: 2007 Dyna Street Bob FXDB Join Date: Oct 4th, 2009 Location: Paris, Texas Posts: 8	Re: Higher Speed Wobble Problems Front tire is a 100-90-19 57h Rear tire is a 190-70-b17 73h both of which are tubeless. now another question of mine would be can a spoke rim be balanced and still be untrue? or if thats even possible. gonna try and get some pictures posted today of other possble questions.

Oct 7th, 2009, 05:56 PM	#8
texasdynaryder New Family Ride: 2007 Dyna Street Bob FXDB Join Date: Oct 4th, 2009 Location: Paris, Texas Posts: 8	Re: Higher Speed Wobble Problems I also thought the same also! if u get time check the pictures that were just uplaoded and check out the front end. the kit came with an aftermarket axle. if looking in the dyna service manual it requires a 7/16 drill bit to fit through the axle tension hole. then butted up against the lower fok tube. my after market axle still has probably near a 1/4 inch to go... and as far as the front rim goes to be centered within the forks. is there any off-set in the front rim?

Oct 7th, 2009, 10:04 PM	#9
Hoople Contributor$ Ride: 2009 Dyna Low Join Date: Aug 16th, 2009 Posts: 506	Re: Higher Speed Wobble Problems My guess is you must have Tubeless tires with tubes in them. There is nothing wrong with that.. Don't see any uploaded pictures.. Hoop!

Oct 8th, 2009, 11:41 AM	#10
texasdynaryder New Family Ride: 2007 Dyna Street Bob FXDB Join Date: Oct 4th, 2009 Location: Paris, Texas Posts: 8	Re: Higher Speed Wobble Problems they are on my profile

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