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[Closed] Making forks more progressive - suspension guru question

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[#9382893]

I've got a set of Zochi 350ncr's and while I'm quite happy with them, they could do with being slightly less linear.

Does anyone know whether there is a limit to adding more oil into the air chamber to achieve this? I've added some in and feels like it needs more to get to the sweet spot.


 
Posted : 14/06/2017 9:06 pm
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Are they an open bath system? What are oil levels on damper side like? For BOS Devilles to make more progressive more oil on damper side


 
Posted : 14/06/2017 9:50 pm
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Just add a little bit at a time until it feels right. Obviously don't fill it to the brim!


 
Posted : 14/06/2017 9:56 pm
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How much have you added? I've never played too much with oil in air springs but I'd assume that if you lower the volume too much you're going to increase the compression to a point where a big hit could blow the oil past a seal. Maybe 10-20% of total volume? It's one of those things you probably can't test very easily!


 
Posted : 14/06/2017 10:25 pm
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Only added an extra 5ml taking it from 25ml to 30ml

Open bath system


 
Posted : 14/06/2017 10:36 pm
 nonk
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That last comment makes me think you are doing it wrong
The oil to affect the spring rate goes on top of the air piston
Undo the top cap on the air side and add it in there
About 20 ml to start with


 
Posted : 15/06/2017 1:13 am
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Been adding it air side via the valve


 
Posted : 15/06/2017 7:01 am
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I've added around 20ml in the past for my 350CRs to help them ramp up a bit.


 
Posted : 15/06/2017 8:48 am
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OK, how much of a difference did it make?


 
Posted : 15/06/2017 10:33 am
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Think of the oil as tokens, a large Fox 36 token is 11cc for reference. The 350NCR has a coil negative spring by the looks of it, so you don't have to worry about the oil dropping through an air transfer port into the negative chamber. You should be able to let the air out, take the top cap off and compress the forks to bottom out, the space (volume) you have on top of the air piston to the top of the stanchion (minus whatever the top cap takes up) is roughly what you have to play with in terms of adding oil. Add 10ml (= 1 token) at a time...


 
Posted : 15/06/2017 10:58 am
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Cheers for the input everyone - added another 5ml and feels better now.


 
Posted : 16/06/2017 1:32 pm