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Post Info TOPIC: Shock Rebound Damping Adjustment Doesn't "Click"


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Shock Rebound Damping Adjustment Doesn't "Click"
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When attempting to adjust the rear suspension rebound damping on my 2005 TTR250 I discovered that it doesn't click when rotated.  This is the knurled dial at the bottom of the shock. The manual describes all of the suspension adjustments in terms of "clicks".

Can someone describe the clicker mechanism?  I believe some part must be missing on my bike, but can't find any detail in the parts diagrams.  There is a small hole drilled horizontally through the rod in the shock, which seems likely to be associated.

For the time being I am making the adjustment by counting the partial rotations from one extreme ("direction A").  However, I suspect the clicker mechanism functions to hold the adjustment dial in place. 

Only other piece of information which seems relevant is that the previous owner told me he always kept the suspension set to the hardest (most dampened) setting.

 

 

 

 

 



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I'm flummoxed confuse with your description of "There is a small hole drilled horizontally through the rod in the shock" because I can't see one on mine.

This picture shows the adjuster clicker which can be seen in Brian's shock bearing replacement page HERE

026.jpg

The knurled clicker is fixed to the shocker and adjusted by turning - may be a bit stiff with crud.

Martyn



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Grey Wulf did a great show and tell on a DIY rebuild of a TTR shock - see http://greywolf.ru/index.php?option=com_content&view=article&id=51:pen-enduro&catid=35:service&Itemid=242

I am not tempted to try this myself and send any suspect shocks to Justin Gibbs for service/repair!

He included a pic of the dismantled rebound mechanism (see below) which shows the pin you mention. My guess is that something in yours has seized.

shtok_vid_s.jpg



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Thanks for your help.  I had visited the board a few times, but just registered recently.  Lots of great information.

 

 



-- Edited by TTRSwamper on Friday 26th of July 2013 11:09:48 PM

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I haven't had the shock apart, so I thought the slot through which the adjustment clicker pin appears to run was just a small hole.  Just the top tip of the slot is visible with the adjustment dial turned all the way down.

I am not sure that I understand exactly what clicks against what.  I don't suppose there is any danger in squirting a bit of lubricant like WD40 into the slot to see if the mechanism would free back up.

Also, who and where is Gibbs?

 



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TTRSwamper wrote:

Also, who and where is Gibbs?

 


See http://ttr250.activeboard.com/t45893091/ttr250-shock-absorber-repairrefurbishmentservice/ 



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Ah yes, Mr. Gibbs.

Seems like the TTR community is much more active in the UK than US.  Curious, really. 



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TTRSwamper wrote:

Seems like the TTR community is much more active in the UK than US.  Curious, really. 


I started a Yahoo TTR250 Group back in May 2001 not long after I bought my first TTR as I couldn't find any information about it. It just grew from there and I just happen to be UK based.

It could easily have happened differently if a TTR enthusiast in the USA or Australia had done the same wink

Brian



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TTRSwamper wrote:

I am not sure that I understand exactly what clicks against what.  

 


A VERY BASIC OVER VEIW OF HOW A SHOCK WORKS ..

Rebound damping....

The clicks yer feel or hear just give a setting point...

What happens in the shock.. as you turn the nob "clicker:

it lifts a small shim "washer style" on the top of the piston which is on the top of the shock shaft...

This changes the size of the opening that the oils flows though.. the bigger the opening the

faster the oil can flow though  giveing less return damping.. by makeing the opening smaller

it restricts the oil flow with gives more damping..

 

Compression Damping...

The top of the shock & resavore is filled with a gas usely nitrogen...

The nob on the res changes the time that the gas in the shock body &

res take to equlize as the shock is compressed... this incresses the gas

pressure in the shock body slowing the compression stroke down..

the longer it takes to equlize the more compression damping...

Moveing the nob towards the + will increass the compression damping

which slows the compression stroke down..

 

 

 



-- Edited by petenz on Saturday 27th of July 2013 03:23:29 AM

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So in the Grey Wulf photo, the pin passes through the slot in the rod.  The dial traps the pin in place.

 

But, what makes the clicking sound?  Is it the pin against the inside of the dial?  Seems like there would need to be a spring of some sort somewhere in the mechanism.



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Ends of the cross pin rideing over serations on the

inside of the wheel.... Click click as it goes over them..

As the wheel rotates on it's thread it moves up lifting

the cross pin that in turn pushs up on the small dia long shaft...

that lifts the shim stack on top of the piston..



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It is surprising how sensitive the adjustment is. Wind it right down and you have to lift the bike to get the swing arm to go back down and, at the top the shock works but is extremely stiff and unresponsive. Finding the in between that suits you isn't easy - just trial and error.

THE ADJUSTER ONLY CLICKS IF THERE IS GOOD PRESSURE IN THE SHOCK TO PUSH THE ACTUATING ROD TIGHT DOWN AGAINST THE KNURLED WASHER. AS SHOCK PRESSURE DIMINISHES THE NUMBER OF CLICKS REDUCES.

Brian



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TTRfan wrote:

It is surprising how sensitive the adjustment is. Wind it right down and you have to lift the bike to get the swing arm to go back down and, at the top the shock works but is extremely stiff and unresponsive. Finding the in between that suits you isn't easy - just trial and error.

Brian


 I think yer can have 2 meany nobs to play with at times... yer always think that 1 click more might be the magic setting... but it never is..



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I'll have another look.  Either that pin is missing or the inside of the dial is so filled with dirt it can't click.



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My rebound "clicker" doesn't click as well. It turns smoothly though, it feels well greased with no dirt grits holding it up, but no clicks.

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Mine was the same, but everything was cleaned out during a shock rebuild recently. It now clicks like a new one.

I'm hoping it works much better than a new one - piston and seal replaced, schrader valve fitted to the remote reservoir, heavier spring and revalve. Will find out soon.



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Shock lower adjuster showing clicker mechanism.jpg

I am just stripping out a shock to replace the bump stop and took a pic of the clicker mechanism. I don't think there is another picture showing the serrations in the "clicker" that causes the clicking biggrin

Unfortunately my job has ground to a halt as I am not sure how to get the end piece off the main damping rod without damaging the chrome finish. The end piece is on really tight. Is there a "technique" or is it just brute force and hope for the best?

Brian

PS This pic may show it more clearly:

Shock lower adjuster apart.jpg



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Excellent photos.  Thanks for posting.



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