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Shock rebound

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Fork and shock springs almost perfect, rider and static. But the shock is trying to bury the front end over anything and throwing rear up in the air(endo) over any rise/water bar/jump in the trail. But if rebound is slowed to control the rear the packing starts immediately and bike is brutal in roots, trail junk, etc. Basically no range of clicks that balance things out. On smooth trails bike is very stinkbuggy. Whats up? Thanks.   

Edited by YHGEORGE

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The sag numbers say otherwise but that is kinda what I am thinking. Front fork sag is always difficult for me but I have an oring on one leg and it shows things to be correct. ??? To compound the confusion I have about three inches of unused fork travel and the shock bottoms very harshly occasionally.

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maybe stiffen up the high speed compression some on the shock? it kinda sounds like its blowing through the stroke, bottoming and causing the kick up. 

That seems logical but I have tried from 1.5 out to full out on HS and it made little difference. At any setting it is brutal on roots. And the stiffer the HS the worse is the stinkbuggy and pitching forward on anything that throws the rear into the air. The typical work on this shock is to lower HS damping and increase the LS for woods use. It feels like just the opposite has been done. Told myself I was done but going to try one more time tomorrow and do some crazy settings just to see what happens. Can't possibly get any worse.

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HSC 1 turn out (no more), Reb 7-8, LSC 10-12 just to try it out.

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HSC 1 turn out (no more), Reb 7-8, LSC 10-12 just to try it out.

Thank you, will do. :thumbsup:  

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Maybe the shock comp is too stiff and it's not absorbing bumps?  If stiffer HS makes the problem worse, that would indicate to me that it's not blowing through the stroke and bottoming (more damping would make that problem better) and it might not be rebound (more comp damping means less stroke which should make rebound kick better).

 

My WR was always tail high off sand whoops in the woods (where you can't be hard on the gas to keep the front end light like you can on a track), I messed with rebound a lot (several revalves) to try to get it right, but it was only when I lightened compression quite a bit that the problem got a lot better.

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Maybe the shock comp is too stiff and it's not absorbing bumps?  If stiffer HS makes the problem worse, that would indicate to me that it's not blowing through the stroke and bottoming (more damping would make that problem better) and it might not be rebound (more comp damping means less stroke which should make rebound kick better).

 

My WR was always tail high off sand whoops in the woods (where you can't be hard on the gas to keep the front end light like you can on a track), I messed with rebound a lot (several revalves) to try to get it right, but it was only when I lightened compression quite a bit that the problem got a lot better.

Your description is exactly what I have. Brutal on roots,kicking and always tail high with front attempting to dig to China like an anteater. Almost impossible to pull a wheelie  to lift/carry the front over stuff.   But still bottoming hard at strange times. Last ride I tried the standard to  softer comp settings and it was a fail. Stiffer reb settings introduced bad packing. Will be testing the high HSC thing later this afternoon. Thanks guys.

Edited by YHGEORGE

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If stiffer rebound resulted in bad packing, you probably have (more than) enough rebound.

 

I don't know what the deal is with bottoming, but if it's harsh on roots and small stuff like that, good chance it's compression and not rebound, IMO.

 

Make a big change, go close to full out on both low speed and high speed comp and see what happens.  I think a lot of guys adjust it a few clicks and decide it didn't help, but I'm not convinced that the average rider can even feel a few clicks.

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Have been from one of the rainbow to the other with damping hs and ls.  Tried GHILL28's suggestion yesterday afternoon and it did help with the balance. But, trail trash, roots etc went from brutal to rigid. Rigid is not an exaggeration. Also noticed something that explains why bike will no longer turn, forks are extended like a chopper and never settle. I was talking with another rider and when I returned to my bike  it was obvious when looking at it from the side. When it is in my shop it is on a stand or I am on it so I never viewed it like that.  But with it being held up with a tiedown sitting naturally, it looked like a Harley with an easy rider front end. Parts have been "updated"  in the forks and now I wonder if the new stuff is the same length as the original. Even though the springs went from .44 to .43 the front end has almost an inch less rider sag than before.  After being pummeled and scared a couple times yesterday I have decided that the current situation is an experiment gone wrong. Things are so far out of whack a screwdriver is not going to fix anything. Whatever I decide, I will never ride it again like it is. Thanks guys, I do appreciate all the  info and suggestions given.

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Going softer springs and getting less sag says something

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I didn't catch, do you do your own revalving? It sounds to me like both ends need to be valved lighter on the low and highspeed compression. Do you know if the rear is physically bottoming or just feels that way from harsh comp. damping. Unfortunately turning in the rebound on the shock also adds more compression damping too, just making a bad situation worse. The forks and shock need to be revalved for plusher comp.

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I had this with an Ohlins TTX I was valving myself. Personally find the LSC controls the chasis behaviour. The amount it compresses on the face of waterbars/jumps/when smashing into berms. The HSC controls and smooths out the sharp edges which equate to high shaft speeds (roots, rocks, logs, square edges; at speed). The rebound just controls the return stroke.

 

I find with a firm LSC it will be a bit rough in the slower chop, and sit up high in the stroke, but a lower HSC will allow it to absorb the harsher hits. I found a smaller clamp on the comp stack was a move in the right direction, especially noticable on the short sharp hits that are prone to kicking the rear high.

 

In regards to the forks, check the length of the spring and the actual preload on them. Sounds like they could be heavily preloaded, causing less sag, and then the lower rate allowing them to blow through the stroke too quickly unbalancing the chasis.

Edited by Jakobi

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What was your exact clicker setting?

Fork setting: Comp-11 out. Reb-10 out.       Shock setting: HSC-1 out. LSC-10 out. Reb-8 out. I need to add that tuner installed a big piston Showa cart with a 12.5mm rod from a Kaw 250f.  Forks(.43) are pre-loaded 5mm. He also installed a 100mm long 2.0KG ICS spring. Forks now have 2 in rider sag which is almost 1 in less than rider sag with the .44 springs. Forks are extended and front end of bike sits up like a dog begging for a treat. Forks never settle for corners etc, always up. Thanks again guys.

Edited by YHGEORGE

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George, have you lost my phone number or what??

If I remember correct awhile back you had issues with alignment or thought something was bent???

There has to be an underlying issue somewhere.

The shock sounds like it could use a piston band.

So one sentence you say the rear is burying the front but in the next sentence you say the front won't dive and it rides like a harley??

The "updated parts" in the forks aren't an experiment. I sold you them to try and help you and that cartridge is better than your stock one. The cartridge that's in there now was actually 2-3 mm shorter than your stock.

And I also machined some off the spring perch so you didn't have excessive preload with the 2-3mm shorter cartridge.

Call me tomorrow

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Thanks. My last several e-mails were never answered. Everything I have described has occurred with different clicker settings. Everything, never in balance. That's ok, I'll call later this afternoon. Thank you.

Edited by YHGEORGE

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