Rear shock setup qu...
 

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[Closed] Rear shock setup quicky

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Coil Van R on a heckler
when seated climbing/flat but rough terrain, back end feels like it is not as compliant as i expect. As if the back wheel goes up and over the rock and then falls into the trough on the other side in a less than controlled manner. I expect the bike to stay relatively flat and the back wheel track up and over with me barely noticing (not talking big rocks here) - like tennis ball size and smaller.

too much preload, too much or too little rebound???? Confuzzled!


 
Posted : 12/06/2011 3:43 pm
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http://locotuning.co.uk/tech-info.html


 
Posted : 12/06/2011 3:46 pm
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it doesn;t help at all!


 
Posted : 12/06/2011 3:47 pm
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You'll be wanting the hovercraft setting then.


 
Posted : 12/06/2011 3:48 pm
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When putting the preload collar on, how loose/tight should the spring be with MINIMUM preload, should it still be moveable by hand or should it just be "biting"


 
Posted : 12/06/2011 5:27 pm
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Remove one turn of preload off and see how that works. If it's still not compliant enough remove another turn. Your collar shouldn't be done up more than two turns from the point at which the collar bites up against the spring.


 
Posted : 12/06/2011 5:35 pm
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Unsure but if you have air in the top chamber, then reduce a little and try.


 
Posted : 12/06/2011 5:43 pm
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AIUI, adjust the preload to give around 25% sag. If you can't get 25% with a couple of turns then you need a different spring.


 
Posted : 12/06/2011 5:45 pm
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think i need to reduce the preload all the way off. Which spring calc is most accurate - tftuned or mojo?


 
Posted : 12/06/2011 6:11 pm
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take an average of them both.

Try speeding the rebound up a little.


 
Posted : 12/06/2011 6:33 pm
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I used TFTuned's calculator, which happened to mirror Santa Cruz's recommendation. For me, weighing about 82kg all kitted up, I use a 400lb spring. I still tried with a 500lb and 450lb, but found that the softer spring allowed it to be plush but still controlled with all the other adjustments. That's for a DHX5 though, I'm not sure exactly how much adjustment you have with the new Vanillas.

I did find that it wallowed noticably before I found the right volume and pressure in the piggyback chamber.


 
Posted : 12/06/2011 6:50 pm
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is the boost valve some kind of low speed compression?


 
Posted : 12/06/2011 6:51 pm
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I'm a bit puzzled by the question:

As if the back wheel goes up and over the rock and then falls into the trough on the other side in a less than controlled manner. I expect the bike to stay relatively flat and the back wheel track up and over with me barely noticing (not talking big rocks here) - like tennis ball size and smaller.

Are you saying:

1) The shock is compressing, or wallowing into its travel in an exagerated manner when you go over a rock?

2) The shock has compressed when riding over the rock, but it extends in an uncontrolled manner once over the rock?

3) Or are you saying that it hasn't compressed when going over the rock in the first place?

Each one is a seperate issue. Can you explain it any further?


 
Posted : 12/06/2011 6:57 pm
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is the boost valve some kind of low speed compression?

Sorry, sneaky edit.


 
Posted : 12/06/2011 7:06 pm
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Funnily enough, I've just bought a CCDB. I supplied my weight and riding style, type of riding its gonna be used for etc, and they sent it back set up for me.

I'm 96kg - cane Creek sent it with a 550lb spring for a Yeti ASR7, which is a linkage actuated single pivot. I achieve 35% sag with this with just 1 turn of pre-load. According to TF I should have a 456lb spring. That'd be way too soft. Mojo is closer with 573lb, but that may be because they recommend 30% sag. I'd go with Mojo.


 
Posted : 12/06/2011 7:06 pm
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mildred - i think its option 3 but not watched the shock as i ride over bumpy terrain i am not sure


 
Posted : 12/06/2011 7:09 pm
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i think i need it softer with quicker rebound so it compreses over rocks and then rebounds back into place/extended sag


 
Posted : 12/06/2011 7:10 pm
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When you are climbing especially, pedalling a bike like a Heckler will result in the chain trying to pull the rear wheel downwards, fighting the suspension action. Great for traction. Not so good for a plush feeling.


 
Posted : 12/06/2011 7:14 pm
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will it not be pulling upwards?


 
Posted : 12/06/2011 7:16 pm
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Not on a high / forward single pivot like a Heckler.


 
Posted : 12/06/2011 7:20 pm
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fair enough, cheers


 
Posted : 12/06/2011 7:22 pm
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sorted, less preload and faster rebound feeels great now 🙂


 
Posted : 13/06/2011 5:08 pm
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cruzheckler - Member
When putting the preload collar on, how loose/tight should the spring be with MINIMUM preload, should it still be moveable by hand or should it just be "biting"

See the section "changing springs" and "setting sag" here.

http://www.foxracingshox.com/fox_tech_center/owners_manuals/07/eng/rear_shocks/van.htm

Ive read that if you put too many turns on the preload you can bend the shaft/rod on the shock


 
Posted : 13/06/2011 5:12 pm
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as i just said - soretd thanks


 
Posted : 13/06/2011 5:13 pm
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I'm glad you've got it sorted, it can be very frustrating when you have an idea of what you want but find it hard to get it dialled in to this ideal. One thing I must say is that having a fairly basic shock like the van r custom tuned by someone like Simon at Loco, TF, Mojo works absolute wonders. I'd consider that next time it needs servicing.


 
Posted : 14/06/2011 4:47 am
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thats the plan matey 🙂


 
Posted : 14/06/2011 6:10 am

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