Rear Shock Compression!!

Discussion in 'Diavel & XDiavel' started by Col1600, May 10, 2020.

  1. Hi all.
    2012 diavel carbon 11k miles.

    So after a stressful few weeks of rebuilding the engine on the Duke. (All great so far)
    I went off for a spirited ride on a mix of roads. Somewhere towards the end of the ride I pulled in for fuel but couldn't help notice that when I sat back on the bike it felt different. I could bounce slightly on the bike and it felt like I could travel a small amount before I'd reach the beginning of the shock resistance. (This is hard to explain). It's like there was free play before the shock would come into play. I rode home but felt like the bike was slightly off. But I have noticed just recently that the front pirelli is starting to wear in it ls.unusual way as have all the front pirelli's that I fitted. And when this happens you can feel the handling degrade rapidly. (Slightly off topic there. And tyres always checked for correct psi...). So today I'm up and out of it and got the bike out for inspection, all seems good nothing obvious. I mess with all the setting on the rear to see if all functions as should. The preload loads up the spring as seen from underneath. The rebound delays the return of the shock as pushing the bike up and down shows a slower return with rebound fully in but the compression at any setting doesnt seem to do anything I can bounce on the bike and it doesnt seem any easier or harder to initiate resistance. This is were I'm thinking the free play is coming from as there is no resistance on compression until it loads the spring. Any ideas or advice would be helpful as a matter of interest is the compression canister a hydraulic unit or gas. As I can see a bleed nipple of some type on the canister from underneath. If so do these units give trouble and are they serviceable or is there a way of checking them convincingly...chaps please dont get caught up with what suspension settings I had or should have because the bike was riding just fine and I can keep up and loose my friends on gixers and s1000's. But there is definitely something not right as of yesterday. Thanks again in advance...
    Colin...
     
    #1 Col1600, May 10, 2020
    Last edited: May 10, 2020
  2. Okay, you need to sit down. It is a know weakness on the Diavel that the rear suspension link rose joint is not up to the job. After all, it’s only a unprotected nylon lined steel ball joint and the nylon wears out. We’ve had two replaced in 24000 miles. The second potential issue is, the pre load pipe that connects from the knob by your left heel and the Sachs shock is supported by a flimsy piece of bent wire in front of the swing arm, that has been known to snap resulting in the pipe getting too close to the rear cylinder exhaust and melting which lets all the hydraulic fluid escape so no pre load. We’ve had that once. Not the nicest or easiest of jobs especially as the swing pivot bolt has been known to seize in the swing arm which might need removing. All that said, the bike has been fixed on each occasion and it’s still Carole’s go to bike. Andy
     
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  3. Thanks Andy but in this case both them items are fine. No play in rose joint and preload adjuster working fine. I can see the preload applying load on spring from looking underneath bike I can see the platform that the spring sits on rising and lowering so increasing and decreasing pre load on spring. I've just been back out to bike and in estimated further on the compression canister and daringly gave the bike looking valve on the canister a stab. If it were on anything else I.e a bike tyre or a pressure vessel it would have released air pressure when I pushed the valve nothing came out. So I now know this unit must be at fault and I'm presuming that these are ment to be at high pressure and maybe nitrogen filled. Hence the free play while sitting on it. Does any of this sound correct?....
    Colin.

    20200510_152734.jpg
     
  4. My experience is watching a mechanic :joy: but your logic sounds good. I upgraded to an Ohlins rear shock so if push comes to shove, I still have the original Sachs if you need something to tie you over. Andy
     
  5. Gentleman Andy..appreciate the offer. I'll see if I can grab some more info on the compression unit. If that's more hassle than its worth I'll be looking for a complete unit, possibly second hand. I've spent way to much money recently on this bike...dont need another money pit. I've old classic VW's that do a good enough job on that....
    Colin..
     
  6. I’m not going anywhere any time soon. Drop me a line if I can be of help. Andy
     
  7. Many thanks Andy...
     
  8. Dublin ain't a million miles from me Paul. Any dealings with them?? Ill contact them for advice or even a setup.

    Colin..
     
  9. Not yet, they were just recommended to me by another couple of Ducatisti when I was enquiring about servicing of Ohlins forks. Let us know how you get on please.
     
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