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balance spring dimensions please

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As per title, does anybody have dimensions of a stock kyb psf balance spring please.

Inner diameter

Outer diameter

Wire thickness

Coil count

Free length

And compressed length if possible.

Many thanks in advance.

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As per title, does anybody have dimensions of a stock kyb psf balance spring please.

Inner diameter

Outer diameter

Wire thickness

Coil count

Free length

And compressed length if possible.

Many thanks in advance.

Which one?

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Which one?

Please elaborate DaveJ? Still learning here but as far as I am aware there is only one 'balance' spring per fork, and then the 'top out' spring. The one that dictates 'pre-load'. Basically I am still struggling with my forks, I want to try lighter balance springs, but I would like to try something lighter than 3.1NM. I have the option to have some made through a supplier in my line of work. Basically it boils down to a supplier in the UK telling me what they have been testing with great results, but I cannot get any description of contact out of them now about purchasing a set from them. I am fully aware I can get 3.1nm springs either from the US, or somewhere in Europe. I have been advised 3 ways, leave it, change it to 3.1nm, or change it to something lighter yet. It is one of those situations (like most suspension related stuff) where there are many differing opinions, and sometimes, someone like myself and my limited knowledge, has to pick a path that 'makes sense'. To me that is lighter, how light I dont really know, testing will be the thing. I am thinking something around 2.5nm, if they come up too soft i can then go to 1 x 2.5nm, and 1 x OEM to get in the middle.

 

I can pull my forks apart and get the dimensions if needs be, just wondering if somebody had one to hand that they could measure it for me please.

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Please elaborate DaveJ? Still learning here but as far as I am aware there is only one 'balance' spring per fork, and then the 'top out' spring. The one that dictates 'pre-load'. Basically I am still struggling with my forks, I want to try lighter balance springs, but I would like to try something lighter than 3.1NM. I have the option to have some made through a supplier in my line of work. Basically it boils down to a supplier in the UK telling me what they have been testing with great results, but I cannot get any description of contact out of them now about purchasing a set from them. I am fully aware I can get 3.1nm springs either from the US, or somewhere in Europe. I have been advised 3 ways, leave it, change it to 3.1nm, or change it to something lighter yet. It is one of those situations (like most suspension related stuff) where there are many differing opinions, and sometimes, someone like myself and my limited knowledge, has to pick a path that 'makes sense'. To me that is lighter, how light I dont really know, testing will be the thing. I am thinking something around 2.5nm, if they come up too soft i can then go to 1 x 2.5nm, and 1 x OEM to get in the middle.

 

I can pull my forks apart and get the dimensions if needs be, just wondering if somebody had one to hand that they could measure it for me please.

Got it.

Let me know what your weight is and I'll run some numbers.

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140 lbs Dave, I am running a 4.6 kgmm in the back and pretty happy with the shock now after clicked, lskyb, Vietze and others helped me with that and the VRS piston in there.

 

The tracks I ride are primarily hard pack, with choppy braking bumps. I am having to run them @ 31-32 psi, and even with 210ml oil still cant bottom them, they feel like they ride high enough at those pressures, but just too stiff. I know I will have to work on the valving, but I would like to get its 'attitude' better before then.

 

Thanks.

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140 lbs Dave, I am running a 4.6 kgmm in the back and pretty happy with the shock now after clicked, lskyb, Vietze and others helped me with that and the VRS piston in there.

 

The tracks I ride are primarily hard pack, with choppy braking bumps. I am having to run them @ 31-32 psi, and even with 210ml oil still cant bottom them, they feel like they ride high enough at those pressures, but just too stiff. I know I will have to work on the valving, but I would like to get its 'attitude' better before then.

 

Thanks.

 

 

Interesting  - it seems the PSF are difficult to dial for riders on the extreme edge of the weight scale - I know I won't be buying a bike with them, I'm 235 -

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Stock 2013 CRF450 3.2 KG springs in mm`s..

 

inner              23.94

outer             30.11

wire dia         3.08

coil count     13.8

free length   188

compressed length..   my press is setup for crankshafts at the moment  but this can be calculated  close enough by the wire dia and number of coils. The normal top out spring must also be considered.

 

 

 

 

For some heavy rider set up tips check this out..

 

 

 

http://www.thumpertalk.com/topic/1022885-13-kx450f-soft-forks-not-what-you-think/page-3?hl=%2Bmrw#entry10963831

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Got it.

Let me know what your weight is and I'll run some numbers.

Dave, did you have any luck?

I can get some springs made, 188 long, in a 2.42nmm rate. With those I can go either straight to 2.42nmm, or combine with an oem spring to give me 2.8nmm...

Thanks

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140 lbs Dave, I am running a 4.6 kgmm in the back and pretty happy with the shock now after clicked, lskyb, Vietze and others helped me with that and the VRS piston in there.

 

The tracks I ride are primarily hard pack, with choppy braking bumps. I am having to run them @ 31-32 psi, and even with 210ml oil still cant bottom them, they feel like they ride high enough at those pressures, but just too stiff. I know I will have to work on the valving, but I would like to get its 'attitude' better before then.

 

Thanks.

The springs that we have would reduce the initial load by a 10.32 lbs.

Going from 32PSI to 30PSI reduces the lifting force by 9.87lbs.

In other words, what a stock spring is at 32, the new spring is nearly the same at 30. This should fix this portion of your issue.

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