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2006 Stratoliner, 2014 Triumph Rocket III Touring, '81 XS650SH Project
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Discussion Starter #1
Yesterday when riding to work on Yamato, I hit the usual bump crossing a bridge. The rear suspension did not behave as it has the last 2,500 miles. Something has changed.

The back of the bike bounced significantly more than before. It did this all the way to work and back home. Every little bump in the road made the bike bounce along the freeway for several seconds.

I am not smart on suspensions at all but realize something is not right here. I searched the forum and YouTube but found not direct correlation to my issue. I suspect my first step is to find the rear suspension adjustment knob and change it. Do any of you have an idea of where I should start trouble shooting?
 

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You mentioned new rear suspension in the title.
Did you change anything from the stock suspension?
 

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Super Moderator "Loose Nut"
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Sounds like the shock has given up. Did it bottom out (spring issue) or continued the up and down motion (shock issue) more than usual?

Coil springs are responsible for dampening the transfer of energy when a vehicle drives over bumps, potholes and uneven roads. The vehicle’s shocks help control the movement of the springs so that the wheels don’t move up and down excessively.
 

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2006 Stratoliner, 2014 Triumph Rocket III Touring, '81 XS650SH Project
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Discussion Starter #5
@Authentic Poser I changed the thread title to be more correct; it is a new issue like @Louisiana Jeff wrote.

@lesblank I have not bottomed out on the bike since I got it. Based on your description, I believe the shock is the issue. The bike bounces while riding along and even tries to buck me off after a large bump. A large upheaval in the pavement (3-4") at 75mph, will cause the back end to be bouncy for 5-6 seconds after hitting it.
 

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The only way to get to that shock is to jack it up and go in from the bottom. I bought the little C - Spanner that fits on a ratchet from cyclegear, you can't use a bigger spanner without it being on a liftjack.

99809
 

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Discussion Starter #9
The only way to get to that shock is to jack it up and go in from the bottom. I bought the little C - Spanner that fits on a ratchet from cyclegear, you can't use a bigger spanner without it being on a liftjack.
It looks like I will finally use the jack pretty Pillion bought me for my birthday a year ago.

The diagram mentions a 'special' tool handed out separately at purchase, I wonder if I have what it refers to.

Now, I just need to figure out how to get Yamato to the back yard where my level surface is...
 

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It is a spanner with a short handle,mine didn't have it. That is why I got the one at cycle gear that fits a 3/8 ratchet
 

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If the ride height hasn't changed, the springs preload is fine.
Bouncing is due to little or no compression or rebound dampening.
That usually comes from insufficient oil in the shock or a failed internal control valve/piston
Some shocks are serviceable, several rebuilders on Google.
 

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Discussion Starter #12
If the ride height hasn't changed, the springs preload is fine.
Bouncing is due to little or no compression or rebound dampening.
That usually comes from insufficient oil in the shock or a failed internal control valve/piston
Some shocks are serviceable, several rebuilders on Google.
You may on to something here. I added air in the tires this morning and found the pavement under the rear half or the bike to be oily.
 

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You may on to something here. I added air in the tires this morning and found the pavement under the rear half or the bike to be oily.
Seals around the shaft are a common failure.
 

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I research the shock and it is a Stratoliner only part, it doesn't even cross to Roadliner, This is the cheapest new OEM.



Here is used on EBay


 

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Discussion Starter #15

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I agree with, bottoming out is due to preload while bouncing is the shock let out.
Most of the time on pickups and cars, when a shock goes bad, that corner of the vehicle starts to bounce at around 55 to 60 mph.
 
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