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Aging & Worn
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Discussion Starter #1
Can you create a front end "shimmy" in your bike, by taking both hands off the handlebars, while rolling? Does it occur at any speed, for moments or for longer, in any double hands off situation?

-Soupy
 

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I can get my '02 FXD to feel like it wants to shimmy if I shake the bars just right but it dies out when I stop shaking. That would be "self-damping resonance".
 

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Shaper Of All Things Metal
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On smooth straight stretches, I'll occasionally take both hands off the handlebars and it's just as stable as with hands on.

Are we correct to assume you've discovered a shimmy in your bike?
 

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MODERATOR
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Soupy, some bikes have a 'deceleration' shimmy, at low speeds, enough to shake the handlebars. If the bike does this at a constant cruise then there is more than likely a problem that should be rectified.

Superbikes and I've had a few, get very light in the front end under violent. full throttle acceleration and this can feel like a 'shimmy,' but isn't.

A 'speed wobble,' is a violent 'shimmy,' that can cause a rider to loose control of the bike. The reasons for this can't really be explained easily here due to the volume of info available, half being supposition and guesses.

Goldwing's have been famous for it forever: It is commonly felt when slowing down, passing through 40mph or less, if the riders hands are removed from the handlebars. Some are worse than others and there's lots of different opinions and cures for the so called problem.

The cure is this: Keep your hands on the handlebars where they belong.

My new (at the time) 1997 and 2012 Goldwing's both had the famous "shimmy," especially when loaded for a touring trip.

I always thought that it was a matter of design geometry: Look at motorcycle triple trees (Clamps) and notice that almost all puts the fork tubes in front of the 'steering head bearings.' "Rake and trail," may contribute also.

On my past Harley Electra Glide, the forks are behind the 'steering head,' essentially 'pulling,' instead of 'pushing' the forks. I could let go of the bars at any time and any speed and the bike was completely stable.

This is just a theory I have, open to comments and opinions.

Worn tires, bad steering head bearings, worn forks and rear shocks, incorrect 'weight and balance,' (Air force vet) amongst other things can be contributing or causing the problem.

Other than the past Wing's, none of my bikes exhibited the 'problem.'

Sam:coffeescreen:
 

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American Legion Rider
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23,610 Posts
I can take my hands off the bars any time and no shimmy. But if I want to play I can hit the bar hard in one direction and it will shimmy and stop on it's own just like DianneB said. In general a shimmy means something is wrong. Tires(pressure or balance) or head bearing(loose or shot). Needs to be corrected and if it the bike you have forsale then tell the buyer or fix it.
 

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Aging & Worn
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Discussion Starter #9
Thanks gang.............

-Soupy
 

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The 43rd Poser
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440 Posts
If your bars shimmy, there are a couple of possible causes.... AND THIS IS BY NO MEANS A COMPREHENSIVE LIST... just somewhere to start.

And no, it is not "normal"....

A. Improper steering head adjustment

B. Front tire not properly inflated

C. Front tire cupped, from either excess mileage or improper inflation

D. REAR tire cupped, from either excess mileage or improper inflation

E. One or both tires out of balance or out of round, possibly ill-adjusted spokes
 

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Aging & Worn
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4,516 Posts
Discussion Starter #11
One comment I would make concerning the spokes on a tire:

I had never owned "spoked" tires before. My previous Honda Shadow had aluminum rims.

I remember reading something somewhere about checking the spokes. I suppose I should revisit that, and get the bike up on the lift, and go round the tires, in the proper fashion, and adjust as needed (if needed).

Anyone seen a good video tutorial for this? I'm sure there IS one.......I just haven't looked yet.

-Soupy
 

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The 43rd Poser
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440 Posts
Truing a rim is an art form.

To truly do it correctly, it should be removed, and the tire dismounted, and set on a truing rack.

But, on the bike, you can take a wrench, and tap each spoke, you should get a little "ring"... if you hit one and get a thud, it may need to be taken to a pro.
 

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Aging & Worn
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Discussion Starter #13
...............on the bike, you can take a wrench, and tap each spoke, you should get a little "ring"... if you hit one and get a thud, it may need to be taken to a pro.
When I had my new rear tire put on last Spring, the fella who did the work is a competent, Tech of good reputation, and Licensed Mechanic. I'll go see him, after I try your test, if I get a "thud."

Thanks,

-Soupy
 

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American Legion Rider
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Remember too that the spokes maybe one cause. Not necessarily "the" cause.
 

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MODERATOR
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Your spokes should all sing the same note: Go all around the rim and if one is out of tune, use a small spoke wrench and tighten it until it sounds the same. There is no good reason to use a "Pro" for this.:frown:

What do you ride now Soupy?

Sam:biggrin:
 

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Gone.
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If you have a whole bunch, especially in one group, then you might want to take it and get it checked for true. If it's just one or two that give you a thud, you can tighten them up carefully by going about 1/8 of a turn at a time until the spoke rings true.

The reason many people should take it to a pro is because they go all out and start turning it 3,4, 8, or many more times, and it starts to pull the rim out of line. Easy does it, and you have to know when to stop.
 

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Aging & Worn
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Discussion Starter #17
I would default to conservative movements (1/4 turn each, for example).

I ride a 1998 Honda Shadow ACE 750cc, Porky.

-Soupy
 

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Pegasus trapped in a human body on a motorcycle
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Soupy, if you can find one, the last generation 750 Magna wheels will fit. Only thing you gotta change is making sure to use the Shadow brake disk and sprocket. (The Magna has a 315 mm rotor and uses a 530 size chain, which is different from the ACE's 298 mm rotor and 525 chain size)
 

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Aging & Worn
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Discussion Starter #19
Biker Dash: If I change ANYTHING about the tires at ALL, I'm still in the market for WWW's.

My 1986 had aluminum cast wheels. But then again, it was a shaft drive, as well. I LIKE the spoked wheels.

-Soupy
 
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