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Rebound faster or slower if compression is adjusted softer

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I have a good setup for HS and enduros but now looking to soften up my compression settings for the occasional extreme enduro. My question is...If I'm running the comp out a lot from my base setup, what direction should I go with the rebound for rocky terrain. Testing is rocks is tough. I've tested a bit in both directions but I'm having a hard time deterring which way actually helps when I might have just made a smother pass through the test section that time through.

Any advise on setup and the reasoning behind it would be greatly appreciated. 

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Why do you think the rebound will need to be adjusted? Rebound pretends to be velocity sensitive, but really it's about spring force so if you haven't changed springs you should be in the ballpark already.

I agree that changes to compression will have you running deeper into the spring, but if your rebound was already valved for that spring..................

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3 hours ago, indy rider said:

I have a good setup for HS and enduros but now looking to soften up my compression settings for the occasional extreme enduro. My question is...If I'm running the comp out a lot from my base setup, what direction should I go with the rebound for rocky terrain. Testing is rocks is tough. I've tested a bit in both directions but I'm having a hard time deterring which way actually helps when I might have just made a smother pass through the test section that time through.

Any advise on setup and the reasoning behind it would be greatly appreciated. 

I would have faster rebound..

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7 minutes ago, Keebler750 said:

Why do you think the rebound will need to be adjusted? Rebound pretends to be velocity sensitive, but really it's about spring force so if you haven't changed springs you should be in the ballpark already.

I agree that changes to compression will have you running deeper into the spring, but if your rebound was already valved for that spring..................

I'm running a softer springs in the forks. I might be over thinking it but I figured that going so far out on the comp would need the rebound adjusted to compensate for going deeper in the stroke. 

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Well, a softer spring will need a softer rebound both internally, and the low speed setting, but that has nothing to do with compression and how low in the stroke you are. The rebound should ALWAYS be tuned for the spring forces at all levels of travel. It's not compression dependent, but spring rate dependent.

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1 minute ago, Hans Schmid said:

I would have faster rebound..

That's what I originally thought but after some testing, I wasn't sure if it was the right direction. Testing in major rock gardens really makes it hard to feel what's going on since everything is rough. 

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Suspension is all about maximizing traction. Think about how much the tire is on the ground. Too much or too little rebound will make it impossible for the wheel to follow the terrain for traction. Test by being on the gas or brakes and try the extremes of your settings. You'll soon find settings that point you in the right direction.

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Rebound damping needs is spring force related

But if you soften the compression enough , you may use more travel on a lighter spring ,and this will actually have more spring force (stored energy ) than before

Only applies if you lighten damping when you fit a lighter spring

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Mog, don't forget that forces and spring rates translate to acceleration of mass which is why we're 'supposed to' tailor a rebound curve to suit. You seem to be suggesting the rebound will only be 'right' starting from ONE ride height.

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4 hours ago, mog said:

Rebound damping needs is spring force related

But if you soften the compression enough , you may use more travel on a lighter spring ,and this will actually have more spring force (stored energy ) than before

Only applies if you lighten damping when you fit a lighter spring

Are you saying that the lighter spring will have more spring force, so it will require more rebound damping?

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If it travels much deeper yes ,you can do the numbers

0.40 spring at 300mm
0.44 spring at 200mm

Both have the air gap which is exponential

The spring force will be way higher on the 0.40

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Rebound damping controls the release of the energy stored in the spring.  On the front it's typically optimized for traction.  Changing springs SHOULD result in a rebound setting change.  Changing compression won't necessarily drive a rebound change, if they were truly independent I don't think it would.  

On the rear a lot of people adjust rebound based on attitude in the air, I don't really like the approach as I've seen the repercussions elsewhere.

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7 hours ago, mog said:

If it travels much deeper yes ,you can do the numbers

0.40 spring at 300mm
0.44 spring at 200mm

Both have the air gap which is exponential

The spring force will be way higher on the 0.40

You are only accounting the rate change at only 1 position though, and only on compression. Suspension action is constant is so the rate constantly changes...

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You are only accounting the rate change at only 1 position though, and only on compression. Suspension action is constant is so the rate constantly changes...
I am showing if the forks compressed to that point with soft springs , then the stiffer ones compressed less , you need more rebound on the softer springs

This is max values in a pretend situation,purely to show rebound damping needs are based on spring stored energy ,and stored energy can be more on a soft spring in some situations

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The same force applied to different spring rates still stores the same amount of energy in either spring. The frequency response is different, however, and the softer spring will require less damping to return properly to steady state than the stiff one. With the load the same, but different rates, it becomes a TIME problem.

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You seen to be thinking backwards

The spring stores the energy

You compress it and hold it ,then release , the softer one more compressed will have more energy

If you put less damping the spring will go deeper

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Spitballin here.....

More high speed rebound and less low speed rebound.

Less low speed to keep it from packin

More high speed to deal with the fact its deeper most of the time.

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