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Discussion Starter #1
Has anyone ever disassembled and rebuilt the forks on their SP-2?
I have mine apart, but can't see the best way to disassemble the cartridge in order to access the rebound valve and the top out spring.
Any help would be great.
 

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I've disassembled my forks, but I never had to pull the top-out spring.
I had previously had sent to Kyle Racing and they installed shorter top-out springs.
To access the rebound valve, I remove the cartridge and slide the damper rod out the bottom. You will have to remove the oil lock piece to do this, but Kyle Racing had already removed mine anyways.
Rather than use the oil lock piece to limit compression travel, Kyle and others prefer to use oil level to cause the air spring inside the fork to limit full travel.
 

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Discussion Starter #3
I am considering removing the oil lock thing. It seems like the only option to get to the rebound valve. The reason I hesitate is once I do this, it will be past the point of no return.
 

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Remember, if you choose to leave the oil lock piece removed, you will have to use the oil level to increase the air spring in the fork to control full downward movement.

Traxxion-Dynamics recommended an oil level of 120mm without spring installed.
I found this to be slightly less than 525cc of oil.

Also, when you're reinstalling the adjust case assembly, be sure and preload the rebound adjuster by turning the rebound adjuster CW the total number of turns it would be at full rebound, which on mine was 4.75 turns as received from Kyle Racing.
Then thread the adjust case onto the damper rod and gently rotate until it stops (don't force it or you will damage the rebound needle).
Then tighten the jam not against the adjust case.

I found thin tappet wrenches the best to loosen or tighten the lock nut onto the top of the adjust case for the fork bolt.
 

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Discussion Starter #6
Thanks Sub for all your help.
I'm calling Dan Kyle tonight when I get home from work.
I'll let you know how everything goes.
Is that the stock rebound valve in that image above?
 

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Discussion Starter #8
I spoke to Dan Kyle yesterday. He was awesome. He gave some great tips on rebuilding my forks, and is sending me a set of Ohlins valves set up for my weight.
He told me what you said Sub about the hydraulic locks.
Cheers to you and Dan for all of your help.
Too bad I have to wait until the spring to try them out.
 

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Here's a comparison between the ohlins and traxxion-dynamics compression valves.
Notice the different port sizes.

Ohlins compression valve


Traxxion-Dynamics compression valve


And here is a comparison between the two compression valves and associated shim stacks.
 

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Discussion Starter #10
Interesting differences. Which do you prefer?
I'm looking forward to mine coming in.
Did you have to file off the end of the thread on the center post first in order to remove the stack?
 

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Interesting differences. Which do you prefer?
I'm looking forward to mine coming in.
Did you have to file off the end of the thread on the center post first in order to remove the stack?
No, it's all held together with a nut.
Look to the far right of the top shim stack and you'll see the nut.
It's assembled with red grade lock-tite, so you'll have to use a heat gun/blow dryer to loosen the lock-tite.

And I am curious what the performance will be, but won't find out until probably next spring when I'll have the bike back together.
Theses valves are part of the entire cartridge kit I bought, but only recently got around to installing.
 

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Why one should change fork oil often.
I bought a set of Ohlins forks off eBay and disassembled them for servicing.
This is the oil that came out.
The oil that came out of RC51 forks was about the same.
That gray color is from metal shavings from the spring rubbing against the fork tube inner wall.
Over time, it can clog up the compression valve causing damping changes.

 

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Discussion Starter #13
That oil is nasty. That's what I was expecting to find inside my forks, but I was pleasantly surprised to find this inside.

Makes sense really. There were tool marks on the lock nut under the fork cap. So somebody has been in there before me.
What fork oil are you using?
 

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That oil is nasty. That's what I was expecting to find inside my forks, but I was pleasantly surprised to find this inside.

Makes sense really. There were tool marks on the lock nut under the fork cap. So somebody has been in there before me.
What fork oil are you using?
Those forks don't have many miles on them. That oil looks almost new.
After a few thousand miles, it will look just as grungy as the oil in the photo.
The recommended interval is every 7500 miles, or 6 months of average use.

I'm using Maxima Race 5 wt oil (16.5 cSt) in both the reworked OEM forks and my Ohlins forks.
 

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Discussion Starter #15
This is a track only bike, so I plan on changing it every season or more depending on usage.
Dan Kyle recommended that I use the Ohlins R&T oil (19 cSt). I'm going to use it this time around, but it's $40 per liter, and I need 1.050L. I think I'll look out for a comparable less expensive oil for the future.
I can't find a Maxima oil listed at 16.5cSt on the list from the link. Is it a special product that you use.
I might use Redline next if I can get it anywhere up here.+

http://www.pvdwiki.com/index.php?title=Suspension_Fluid

Cheers
 

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Discussion Starter #17
Hey Sub,
When you had your forks built at Dan Kyles, do you by any chance know what your Installed Pre-load was?
 

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Hey Sub,
When you had your forks built at Dan Kyles, do you by any chance know what your Installed Pre-load was?
Sorry I don't.
It was on my to-do list when I had them apart, but I had to order some special tools and then went out of town on business and it slipped my mind.
 

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good thread, ive always had my forks built as it was something i wasnt confident tackling myself (although i am very mechanically inclined). im looking at buying a set of built forks for my rc at the moment, but when it comes time for servicing i may attempt it myself this time.
 

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Discussion Starter #20
good thread, ive always had my forks built as it was something i wasnt confident tackling myself (although i am very mechanically inclined). im looking at buying a set of built forks for my rc at the moment, but when it comes time for servicing i may attempt it myself this time.
If you have the correct tools, it's really not bad at all. My two biggest challenges were the hydraulic lock piece, and cutting the top-out spring down.
Once I decided to remove the hydraulic lock piece, which was pretty simple if you do it the way Dan Kyle told me to do it, things went pretty smooth from there.
 
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