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SSS FORKS harsh on small bumps

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2006 yz 250 48 year old expert riding mostly desert some moto. I weight 185 no gear forks need service so I thought I would try to re valve at same time forks have always been harsh on small square edges at speed. I have not played with oil level or weight has any one had luck by just changing these? I have not done valving changes before I am hoping some one could help me with some stacks my thought was to start by taking a few face shims off of base and mid valves.

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I have a 2006 YZ250 and I weigh 185. I turned the compression damping full soft and it helps over small trail trash. I used the manual's specified oil capacity the last time I rebuilt the forks.

 

I should note that when I rode in Moab, Utah, with the abundant sharp edge rocks, the forks did feel harsher.

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I have found that the closer you get to the Maximum oil volume in the outer tubes the more harsh they become.  If the SSS stuff has a flaw it is the in the conditions you described.  If your spring rate and valving is close which it should be at your weight you can usually tune it out with the oil level and compression clickers.

 

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THANKS FOR THE INPUT I THOUGHT MAY be I could tune with  oil level just wa.nted to see if some had good results doing so when I go to far on comp the bike wallows and dose not handle big hits I am still interested in valving it would be fun to do

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Try running 325cc instead of 350 in the outers.  If bottoming becomes a problem, you can use a 5-8wt in the outer volume instead of the lighter 2.5-5wt used in the inner cartridge.  Drilling the free pistons and removing the upper seal from them will help very slightly, but will prevent the pistons from breaking.  Essentially, the harshness comes from the mid valve, and to soften that, you can play with reducing the shim stack or adding more float. 

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Try running 325cc instead of 350 in the outers.  If bottoming becomes a problem, you can use a 5-8wt in the outer volume instead of the lighter 2.5-5wt used in the inner cartridge.  Drilling the free pistons and removing the upper seal from them will help very slightly, but will prevent the pistons from breaking.  Essentially, the harshness comes from the mid valve, and to soften that, you can play with reducing the shim stack or adding more float. 

I may try running 320cc in my yz250 and use some of the heavier weight fluid.

I have been using the Yamaha S1 Fluid in my Forks and Shock. What weight fluid is the S1?

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My 2015 YZ250 is valved slightly on the soft side. With that being said, could I tune the Forks and shock with a heavier weight of fluid?
If so .....how high of a weight could I go to? Would 10w be to extreme for the Forks and shock?

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Before changing anything in the valving, oil weight & volume (oil volume mostly affects the last 1/3rd of travel)

for better low speed / small bump compliance you should try a pair of softer ICS springs.

The stock rate is about 2.0kg/mm, try a set of 1.6kg/mm.  

(IMO 1.4kg/mm are ok for trail/off-road only, not for motocross / big jumps)

Edited by mlatour

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sorry posted twice didnt know my first post posted

Thanks for changing it… don't like those double posts!
I am 185 without gear 2009 yz250. Tapio Niivila convinced me that the stiffer the springs the softer the ride. I went against common sense and trusted him. I have .48 in the forks and 5.6 in the shock and it is the softest most plush bike I have ever ridden. I use full travel at both ends every ride and they are stiff enough to hold the bike up high in the travel where the valving is naturally the softest for the harsh trash you describe. Just food for thought.
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Thanks for changing it… don't like those double posts!
I am 185 without gear 2009 yz250. Tapio Niivila convinced me that the stiffer the springs the softer the ride. I went against common sense and trusted him. I have .48 in the forks and 5.6 in the shock and it is the softest most plush bike I have ever ridden. I use full travel at both ends every ride and they are stiff enough to hold the bike up high in the travel where the valving is naturally the softest for the harsh trash you describe. Just food for thought.

Now that is what I am looking for in my 2015 YZ250. I want it to ride a little higher up in the stroke.
Would I just need a rate stiffer springs in forks and a Rate stiffer on rear?
With all my gear on I weigh 185lbs.
My bike has been revalved and has been re sprung in the forks and on shock.

I don't know exactly my spring rate on forks but all most sure they are heavier than stock. The rear spring I believe is a 5.1kg. Fork springs may be 40kg but not positive.

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I wouldn't worry about the titanium. Better to have the correct spring rate. Some people like the steel spring better anyway.
Yes, my valving is not stock. all forks are going to be hydraulically softer or less harsh in the beginning portion of the travel. don't be afraid to spring on the stiffer side, I was very pleasantly surprised. The stiff rear spring lets me have very little preload and makes it feel soft if that makes sense, and both ends are always ready for big hits.
I believe you are correct in post number 14.

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Now that is what I am looking for in my 2015 YZ250. I want it to ride a little higher up in the stroke.

Would I just need a rate stiffer springs in forks and a Rate stiffer on rear?

With all my gear on I weigh 185lbs.

My bike has been revalved and has been re sprung in the forks and on shock.

I don't know exactly my spring rate on forks but all most sure they are heavier than stock. The rear spring I believe is a 5.1kg. Fork springs may be 40kg but not positive.

Was it re-sprung and re-valved for you? I believe your bike is .44 stock fork springs and with a 5.1 in the shock that doesn't sound too bad for you at 185 with gear. Not knowing your riding style/ability I would say try stiffer rates if thats what your gut is telling you. Find someone local who does suspension work and swap for a try. I am just amazed how soft and smooth this bike feels with stiff springs. I am almost always in the woods and I still use 100% of the travel. I don't run a lot of compression damping because I'm usually in the woods but I must say it is really very good on the track also.

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Was it re-sprung and re-valved for you? I believe your bike is .44 stock fork springs and with a 5.1 in the shock that doesn't sound too bad for you at 185 with gear. Not knowing your riding style/ability I would say try stiffer rates if thats what your gut is telling you. Find someone local who does suspension work and swap for a try. I am just amazed how soft and smooth this bike feels with stiff springs. I am almost always in the woods and I still use 100% of the travel. I don't run a lot of compression damping because I'm usually in the woods but I must say it is really very good on the track also.

Yes .....it was re sprung and revalved for me by a Local suspension tuner. I race MX only in the vet 40+ and 45+. It's not terribly soft but I would like for it to ride just a little more higher in the stroke.

It probably has .46kg springs up front, I still have the stock springs for it.

My settings look like this on it.

Sag is 102mm

Free sag is 30mm

Fork comp=11 out

Fork rebou=15 out

Shock Comp=11 out

Shock rebou= 12 out

Shock HSC= 1 1/2 turns out

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14 hours ago, CaptainKnobby said:

My 2015 YZ250 is valved slightly on the soft side. With that being said, could I tune the Forks and shock with a heavier weight of fluid?
If so .....how high of a weight could I go to? Would 10w be to extreme for the Forks and shock?

First, only the oil in the inner chamber has any direct effect on damping, because none of the valving is in the outer chamber.

Second, going up or down a couple of grades has very little effect on damping anyway, because the fork/shock is designed to work the same over a broad range of oil viscosity.  Suspension oil heats as the unit operates, and the shift in viscosity from cold to normal operating temperatures is usually greater than the difference between, say, a 3 and a 7wt.  The valving regulates internal pressure differences, and it simply opens farther to accommodate thicker oil.

The outer chamber is affected by heavier oil only when an "oil lock" or oil braking system is used for bottoming control.  The SSS fork and several others use a cone shaped socket in the bottom of the fork that the end of the damping cartridge enters into during the last 1.5" or so of travel.  As the damper runs deeper into the socket, the taper causes the space available for oil to escape around the cartridge to grow smaller, slowing the compression stroke to a stop more gracefully than a bumper can.  Because the clearance between the cartridge nose and the oil lock is a "fixed" orifice in effect, using a heavier oil here does make a difference.  Otherwise, the outer oil does nothing but lube the tubes.

Outer oil level changes things because raising or lowering it changes the volume of trapped air in the fork, and the trapped air becomes a part of the effective spring rate when it's compressed.  Less oil = more air = less resistance to compression, or a softer "air spring".  You will feel the difference in about the deeper 60% of the stroke.

Using a heavier than recommended oil, like the ten weight, in either the fork cartridge or the shock will put more stress on the valving shims because it will bend them farther to achieve the same internal balance of pressure, and it will increase the heat generated.  All that while having no particular effect on damping.  I don't recommend it.

Even if your bike is a little on the soft side, you should be able to crank down on your clickers to get a reasonable amount of resistance from it.

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