High Speed Wobble.

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panhog
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High Speed Wobble.

#1

Post by panhog »

The most common reason for high speed wobble is loose or worn neck bearings. Correct? Here is my deal. For years I have run my solo seat mounted to the frame. A shaft threaded on both ends ran though the frame cross member just in front of the shocks. Seat mounts with L brackets to shaft. Mount for front of seat fits in center post. So. I sat low and rear in frame. Never had a problem with wobble. Steady as a rock at all speeds. Recently I put the pogo seat setup on. That is when the high speed wobble began. My theory is now I am sitting high and forward. Higher center of gravity and weight shift forward. Thus the high speed wobble. Worn or loose neck bearings? Questions? Suggestions?
jdpan
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Re: High Speed Wobble.

#2

Post by jdpan »

Could be a lot of things. Worn wheel bearings, swing arm bearings, neck bearings, worn fork bushings, Put it on a lift and do some poking around.
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Re: High Speed Wobble.

#3

Post by Pomike »

Are you talikng about your ' 64? Could be frame crack too. Mike
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Re: High Speed Wobble.

#4

Post by john HD »

i would start with tire pressure and steering damper.

then look closely at the parts you used to mount your new seat. a loose t bar bushing at the front can give an illusion of a wobble. keep in mind one side of the frame mount is threaded so you can tighten the assembly.

john
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Re: High Speed Wobble.

#5

Post by 58flh »

I agree with JOHN!---Check the simple things first!--High-speed wobble can be a # of things. Pressure/balance of wheels, Berings-(excess in star-hubs), neck-berings, Wheel alignment (front-rear), Drumbrake rubbing!, Loose tranny & motor!--ETC.!--Process of elimination!--One clue as you mentioned!---Your center of gravity is shifted more forward & higher--(as was mentioned check T-bar/&pogo,& FRONT-END to start!---DONT forget your drivechain!!!!---GOOD-LUCK,Take your time & it will jumpout at you!--Also when the wobble starts , mark speed & if it goes away at even higher speed))-theres a clue for driveline inspection starting with front-end!--If wobble is very bad DONT PUSH HER!! to see if it smooths out! STAY-SAFE!----Make sure tire wear pattern doesent present any cupping!!!!,Alot of us including myself tend to run LOWER PRESS. I have had that bite my ass 1 or 2 times :!: ---BE PERSISTENT & you will find the culprit!----RICHIE
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Re: High Speed Wobble.

#6

Post by neilw »

Being an old autowrecker and having bought 1000's of wrecked cars ( and a few Harleys) I found if the bead was seperated or broken the tire would wobble .to check for that is easy ,you raise the bike and spin the wheel stand back 3 feet or so and see if the tread runs straight ,if it weaves back and forth ,you have a broken belt in the tire.
Neil
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Re: High Speed Wobble.

#7

Post by 58flh »

NIEL---sounds like your an old-hand at this!--just be persistent & process of elimination!--you no-doubt will find your problem!--Richie 8)
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Re: High Speed Wobble.

#8

Post by joe »

I had something similar but would really notice it when I would turn. It turned out to be a loose rim, I took the tire off an retorqued the loose spokes (of course being careful to maintain proper runout in both planes). Everything is fine now.


Joe
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Re: High Speed Wobble.

#9

Post by RUBONE »

Tire wear and inflation can also have a dramatic effect on high speed handling. By shifting the weight up and forward you made a change in the overall weight bias. Are all other components stock? Fork length, shock length, swingarm , etc? If the Swingarm pre-load is not correct a shift of the weight forward can allow it to lighten slightly (shocks extend more) and will make any looseness very evident. If the steering head bearings are too tight it can be even worse than too loose.
Plenty to look at. Good luck and keep the questions coming.
Robbie
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