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Suspension tuning


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Today my son and I were out getting to know how our bikes handle jumps. My son noticed my bike has a tendency to bounce upon landing. Not knowing the original owners weight/preference I dl'd the FSM .pdf and set everything back to stock. One thing that really got my attention.. the setting on the bottom of the forks, R side was 2 clicks out from stock, the L fork was 100% IN!!!!!!!!! :eek: I hope it was just a mistake he made. The bike felt fine to me but I have no reference.

I was going to set the rear sag but, how in the world do I access those jam nuts? I assume I have to remove the airbox? We ride in mostly sand so I was going to run 6mm preload.

Also, if I do still bounce, Which way do I adjust and what exactly?

TIA for helping a total noob! Help me out guys, I'd rather look a fool on here than in front of my son.:banana:

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You can access the lock ring with a long screwdriver or punch, and a hammer.

Many turn the spring adjuster with the same aforementioned tools while some can get their little arms in and twist the spring from the bottom.

http://www.tootechracing.com/suspension_tips.htm is a good tutorial and here is one of the million youtube videos on sag adjusting:

Turning the spring UP loosens and gets you more sag.

Turning spring down, clockwise, stiffens and takes sag out.

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About your bounce. I doubt if the compression setting is going to make a huge difference and it controls the rate at which the suspension compress when you land. The think that control the bounce is the rebound / speed your suspension de-compresses.

Go 2 clickers in on the top of your front forks and 2 clickers in on the bottom setting of the rear shock. Go in 2 at a time until you feel ok.

Sag controls the average height your bike will carry your weight - important but again not a great influence on your bounce.

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I think the stock spring is straight rate, not progressive. Usually progressive springs the loops get closer together until they touch. Seems to me the leverage is what changes, and you can dial in the compression and rebound damping to affect the way it feels as well. When it feels like you're running a flat, that's about right.

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Putting it all together, it looks like this:

First, see if you can set your race sag. Once your race sag is set, your static sag (without you on the bike) will tell you if your spring is too weak or stiff.

Second, adjust your rebound (bottom on the shock, top on the fork). The rebound damps the motion of the spring as it un compresses. Without it, your bike would be a pogo stick. Screw them in until your bike doesn't bounce. If the back end wants to kick up off a jump, put more rebound in the back and less in the front and vice versa. If you have too much rebound, the suspension will stay down too long when compressed. On the rear shock, the rebound also affects the compression some, so you want to square away the rebound first.

Last, adjust the compression. The compression damps the motion when the suspension is being compressed. You need enough compression so that your suspension doesn't bottom out over jumps. The rear shock also has a high speed adjustment which affects it when you hit sharp edged objects like roots or rocks (I'm from the northeast).

Don't be afraid to turn the screws all the way in or out if necessary. That's what they are there for. If you turn them all the way in or out and can't get the results that you want, then you need to change the valving inside the suspension, which is a whole new topic.

That's my understanding anyway.

- Brad

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At that weight, your actually getting to the point of needing a 5.6kg/mm shock spring, and .47kg/mm fork springs. I like the MX Tech spring calculator, it takes into account your riding gear to calculate your spring rates. So throw on all your gear and go step on the scale, then punch in your total weight into the MX Tech spring calculator.

http://www.mx-tech.com/index.php?id=spring_generator

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On the sag setting.

Step 0) Preload has been set to 6mm.

Step 1) Measure the distance from a point on the swing arm to the inner side panel bolt with the bike on a stand.

Step 2) Set the bike on the ground and remeasure. This will give me "free sag".

This measurement is usually 30mm difference?

Step 3) Next check the rider sag using the same method but once the bike is on the ground have the rider, fully suited, set on the bike.

The difference here needs to be about 3 3/4 - 4inches?

Step 4) Once adjusted, repeat steps 1 & 2.

The measurement needs to fall into a 25-30mm difference?

Am I on the right track here?

And as pointed out above, I need to swap to a 5.4-5.6kg rear spring anyway.

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On the sag setting.

Step 0) Preload has been set to 6mm.

Step 1) Measure the distance from a point on the swing arm to the inner side panel bolt with the bike on a stand.

Step 2) Set the bike on the ground and remeasure. This will give me "free sag".

This measurement is usually 30mm difference?

Step 3) Next check the rider sag using the same method but once the bike is on the ground have the rider, fully suited, set on the bike.

The difference here needs to be about 3 3/4 - 4inches?

Step 4) Once adjusted, repeat steps 1 & 2.

The measurement needs to fall into a 25-30mm difference?

Am I on the right track here?

And as pointed out above, I need to swap to a 5.4-5.6kg rear spring anyway.

You're on the right track.

I can tell you as a 190#'er, you'll need new springs front/rear to get this thing working great. You'll be chasing clickers forever unless you spring it right. Once you get it dialed in, it's a really smooth suspension.

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Second, adjust your rebound (bottom on the shock, top on the fork). The rebound damps the motion of the spring as it un compresses.

Isn't compression damping on the top of the fork and rebound damping on the bottom? Or is it backwards on the wr's?

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