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KYB PSF custom lighter balance springs, they're in..........

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As the title, thanks to some of you helpful guys getting me measurements of the OEM balance springs, I had some custom made, in a 2.4n/mm rate, stock being 3.2n/mm.


Long story short, I am light, light for a 450, 140 lbs infact.


I have been running my forks with the OEM balance springs around 30-31.5 psi, this is more pressure than I need, but any lower and the forks sag too much......I have been running 210ml in the outer chamber, and have yet to bottom the forks in 8+ hours riding, and thats trying to bottom them out at times. They beat the crap out of me on normal braking/accel bumps.


with 31.5 psi in the forks (I had them a little higher than usual due to my last race meeting being a 'bogger' heavy wet clay) my sag measurements are as follows. (please take them with a pinch of salt, trying to do it on my own using an o-ring on the fork leg, plus the nature of stiction with these forks, but I am sure they are pretty good) These measurements where just done in regular clothes as a comparison thing too.....


41.5mm static

53mm race


Now with my new 2.4n/mm balance springs in, at 28psi, i get;


35mm static

58mm race


With 26psi i got:


42mm static

62mm race


Another interesting note is that with the stock balance spring, to get the forks 'topped out' (off the bike, laying on side) it took around 32-33 psi, with my new lighter balance springs, it takes 26-27 psi to top them out.


At 28psi the forks feel better just bouncing in the garage, but as we all know, the real test is going to be riding the thing, this hopefully will happen next weekend........... nursing a swollen, and black n blue right knee at the moment.

Edited by DHS_sponsored

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They seem good, not really had a chance to test them properly On familiar territory but I didn't even think about fork action at my last race, which to me is a positive. I ran 28.5 psi and 235 oil. Going to try lower psi at some point see how it feels, and adjust oil amounts too. Here in the UK the weather is wet at the moment so bit alot of riding to be done over winter now :(

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The mid is this vrs blow off set up which I left alone, the base is a single stage stack, didn't measure it up to be honest, can't even remember if it was an oem or vrs piston now! Dohh. I left the stacks as is, bar the bleed stack, where I halved the face shims. I don't want to do too much at once. It's going to be work in progress, as I say above, the weather is crap here and so few tracks around that testing is difficult. The lighter balance springs I think are for sure a step in the right direction though, I will have to see how I go. I am thinking that I will most likely end up with softer rebound now my pressures are reduced, and I am sure I will have to go softer in the compression. I may even try a 2 stage base now the fork holds itself up nicely.

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