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DRZ SM Shock is shorter..proof inside

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OK it kind of is... but not really....and many parts are the same.. Confused yet???? You should be with good reason. Suzuki used off the shelf parts to "make" a shock fit their SM model.. 

 

 Read on..

 

I was sure the DRZ SM shock was "different" in that it was "shorter" then the S or E shocks.

 

I just never took the time to have several different model DRZ  shocks apart at the same time to confirm HOW it was shorter.....Till today.

 

The DRZ SM Showa shock is physically the same length, uses the same body, same rod length (but machined differently), spring mounts and retention as all other shocks DRZ400 (of the same later style with the High Speed compression adjustment "Blue Nut") 

 

The difference in extended length is the valve and shim stack, and the machined shoulder on the rod.... the SM valve is physically thicker, and the over all shim stack from clamping shim to top shim is what makes the SM shock "shorter" when coupled with the location of the machined shoulder on the shock rod.

 

SAM_0196.JPG

 

The E shock valve stack at 28.43mm tall

SAM_0201.JPG

 

The SM shock valve stack at 32.45mm tall 

SAM_0200.JPG

 

 So approximately 4 mm difference.

On a DRZ shock travel to seat height is 4:1 

That means the SM shock accounts for 18mm LOWER seat height then if the same bike had a DRZ E or S shock. 

 

The SM Shock also has a spacer that limits compression travel.

SAM_0202.JPG

The shim is 2.45mm thick 

 

So the small exterior spacer limits compression travel at the wheel 9.8mm

 

What this all means is the shocks are mostly swap-able... in that a shims and the valve are not going to wear out, adjusters are the same.body is the same.ect, ect... only the SM shim stack and the shock shaft are different parts from other model DRZ shocks (with the blue nut, high speed compression adjuster).

The shock shaft of the SM is machined differently, so that the thicker stack is closer to the yoke end of the shaft. 

 

I used shocks from a 2003 DRZ S, 2001 DRZ Kicker, 2009 DRZ SM, 2003 E to confirm all the above.

 

And now we have the rest of the story....

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the bump rubber is taller on the SM shock I have compared the my S shock and hence reduces travel

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the bump rubber is taller on the SM shock I have compared the my S shock and hence reduces travel

Might be you have a worn bumper or non stock or a different year.. all of the shocks I have mentioned above use a 56mm tall bottom out bumper. 

 I cant account for your different observations, only that mine are as above

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Nice of you to do the research,  im sure the question of     ''Will a E/SM/S''REAL E/S/SM'' fit my E/S/SM''REAL E/S/SM'',   nice to have it cleared up.

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Great work :thumbsup: , but when looking at the shim stack... that thick backer shim (~41 mm in diameter and 12 mm ID) sits on a machined shoulder (shock shaft).  So if the SM and E/S shock shafts are the same... then I can't see how the shock is shorter.  The thick backer shim (at full shock extension) rests against that rubber bumper within the seal head.  So if the shock body (circlip position for seal head), seal head and shaft are the same it can't be shorter.

 

My DRZ400S shock had a 18 x 0.6 mm shim under that 41 mm backer, so if you removed that then the shock would be about 0.6 mm shorter.  So I'm thinking that the machined shoulder on the SM shock shaft must be at a different height...  But hey I'm just spitballing.

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Great work :thumbsup: , but when looking at the shim stack... that thick backer shim (~41 mm in diameter and 12 mm ID) sits on a machined shoulder (shock shaft).  So if the SM and E/S shock shafts are the same... then I can't see how the shock is shorter.  The thick backer shim (at full shock extension) rests against that rubber bumper within the seal head.  So if the shock body (circlip position for seal head), seal head and shaft are the same it can't be shorter.

 

My DRZ400S shock had a 18 x 0.6 mm shim under that 41 mm backer, so if you removed that then the shock would be about 0.6 mm shorter.  So I'm thinking that the machined shoulder on the SM shock shaft must be at a different height...  But hey I'm just spitballing.

Your dead on..apparently my description of what I found was not sufficient to get that across..

 

 The shock rod is the same OVERALL in length. Not in design.

 

 NOT the same from clevis to the machined shoulder that the machined washer rests against.

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Your dead on..

 they are the same OVERALL length.

 

 NOT the same from clevis to the machined shoulder that the machined washer rests against.

 

So, then they're not totally interchangeable... not a big difference, but one nonetheless.  So when the shock was still assembled, did you measure from shock eyelet to eyelet (at full extension), any difference?

Edited by bmwpowere36m3

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So, then they're not totally interchangeable... not a big difference, but one nonetheless.  [/qoute]

No not totally.. sorry thought I had made that clear..So when the shock was still assembled, did you measure from shock eyelet to eyelet (at full extension), any difference?

No not totally interchangeable, not ALL parts will swap over.. many will... .. sorry thought I had made that clear..

 

I'll have over all extension and compressed measurements tomorrow. 

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No not totally interchangeable, not ALL parts will swap over.. many will... .. sorry thought I had made that clear..

 

I'll have over all extension and compressed measurements tomorrow. 

 

So if I understand correctly, the SM shock is shorter by 4 mm (because the shaft sits that much more within the shock body as compared to a E/S shock) and the shock travel is 6.45 mm shorter (shaft sits 4 mm further in + 2.45 mm plastic shim limiting compression).

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So if I understand correctly, the SM shock is shorter by 4 mm (because the shaft sits that much more within the shock body as compared to a E/S shock) and the shock travel is 6.45 mm shorter (shaft sits 4 mm further in + 2.45 mm plastic shim limiting compression).

Mostly..

 the SM shock is the SAME length overall as in the parts..

 But once assembled it is approximately 4mm shorter in extension and 2.4 shorter in compression (will confirm assembled length tomorrow) 

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Mostly..

 the SM shock is the SAME length overall as in the parts..

 But once assembled it is approximately 4mm shorter in extension and 2.4 shorter in compression (will confirm assembled length tomorrow) 

 

So far all in intents and purposes its shorter... barring a fully disassembly of the shock and buying some other parts (expensive parts, like the shock shaft, piston, and maybe shims) it'll be a different shock.  Whether that difference makes a difference is another thing.

 

Waiting to see your updates.

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When I changed out my 2000 shock for a 2010 shock there was a difference in lenght. Your investigation has exposed the reason. Now I and everyone else knows why. Good work Eric. Pro-Action Bob did all the work on my shock and combined the 2000 with a new Pro Action high/low valve and new spring into a 2010 making one unit . I wanted the 2010 shock because it also has rebound damping that the 2000 shock did not have.

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When I changed out my 2000 shock for a 2010 shock there was a difference in lenght. Your investigation has exposed the reason. Now I and everyone else knows why. Good work Eric. Pro-Action Bob did all the work on my shock and combined the 2000 with a new Pro Action high/low valve and new spring into a 2010 making one unit . I wanted the 2010 shock because it also has rebound damping that the 2000 shock did not have.

So your 2010 shock was an SM... did you know that at the time or was it a Ebay kind of deal...

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Now that I think about it the difference may have been the way the adjusters were tightend. I was just using a tape measure and did not disassemble or even think of the adjusters. I am not even using the right terms...LOL!

 

I know one thing for sure is the piston/valve is way heavy. Pro-Action has a light weight version for around $90.

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No not totally interchangeable, not ALL parts will swap over.. many will... .. sorry thought I had made that clear..

 

I'll have over all extension and compressed measurements tomorrow. 

Once assembled, eye to eye as measured using a center pointer on my lathe and measured by a DRO

 

SM shock 447.1 mm

E Shock 459.0 mm

S Shock 458.9 mm

 

Which supports the other finding of 4mm difference between over all extended length of the SM and E/S/Kicker Showa shock (later year ones with the Highspeed compression adjuster) 

 

The SM Showa shock is 4mm shorter in extension travel then the E, S, kicker,, which accounts for 16mm lower bike height, due to the 4:1 ratio of the linkage.

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I realize this is old, but I have been searching around and rather than start a new thread, my question seems to fit well here. 

 

Are the SM inverted forks compatible with the other model triple trees? I am converting my 2001 kickstart only to an SM, so would the SM model inverted forks fit my current triples or would I need to chase down a SM triple as well? 

 

Thanks

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I realize this is old, but I have been searching around and rather than start a new thread, my question seems to fit well here. 

 

Are the SM inverted forks compatible with the other model triple trees? I am converting my 2001 kickstart only to an SM, so would the SM model inverted forks fit my current triples or would I need to chase down a SM triple as well? 

 

Thanks

You will need triples to match the larger size upside forks 

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