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I waited for some time to post this thread until I had enough rides and information to get a good read on the AK-20 cartridges. I put in the cartridges myself, and first found the lack of an assembly diagram caused me to assemble the kit improperly. The plastic spring guide was the offending part. A tiring Internet search finally produced a picture of the proper setup. I have serviced a bunch of forks but nothing like this kit. Back apart and back together and all was well.

I set the bike up based on the recommended settings, and found the bike to be almost unrideable. The front end was very shakey, even with my stabilizer at 8 clicks. Back to the garage to check the sag. I had to set the preload to 8 full turns (6 suggested) in to find a happy place. Well, I know enough to know that that setting eats up too much travel leaving me a stiff remaining compression stroke. So, I called Dan (great guy) asking for stiffer springs and he promptly sent me a pair of .95 kg springs to replace my .90's. I weigh 205 lbs. with gear.

Back to the bench and back apart. I set the sag and ended up with a preload right at the initial recommended 6 turns in. I rode the bike a ton making adjustments to compression and rebound and I found that the 2 1/2 turns out from hard on the compression was not anywhere near enough out on the compression. I like stiff suspension, but that was jarring. I ended up with 3 1/4 turns out for a smoother stroke and three turns out towards fast for the rebound. The forks went from soft to hard without much transition based on the recommendations. Now they are much better.

The recommended oil height was 100 mm., which struck me as way too much oil. Not knowing the cartridge flow requirements, I left it that way. I am going to take it apart one more time, change the oil height to 110 mm from top and dial in some more compression dampening to get a smoother stroke. I feel that I am 85% where I need to be, and hope that this will get me to my goal.
 

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Interesting...

I've just installed them in my bike...waiting on a break in the weather to try them out.
Hopefully this weekend.

I'm curious to see how they work out for me.....starting with his settings...We'll see
 

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That's how I like it too, less preload and stiffer springs. My preload is all the way out (none) and the .90 give me around 37-38mm rider sag. 100mm oil level sound a bit drastic to me... at 130mm I need to hammer the brakes really hard to bottom out... and still.

Can't wait to see what you come up with...
 

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I just installed them myself....the instructions must have been changed because mine was clear and simple how the install went....even had a diagram to show where all the pieces went...
 

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Yeah, mine came with straight forward instructions.
Went together as expected.

I did set the oil at 100mm.
Sounds like that may be a little much.
 

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That's how I like it too, less preload and stiffer springs. My preload is all the way out (none) and the .90 give me around 37-38mm rider sag. 100mm oil level sound a bit drastic to me... at 130mm I need to hammer the brakes really hard to bottom out. and still.

Can't wait to see what you come up with...
That's about how I set up my Online forks.

Use a combination of oil fill and compression dampening

to get full travel with a half to three quarter inch left after hard

braking down a hill , almost doing a stoppy.
 
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Mine went together just fine.

2 turns in on preload to get sag at around 36mm.

Think i turned in compression damping about 3/4 a turn.

AK20's are a great compliment to the Penske double clicker.

And yes Dan is a great guy to work with.
 

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That's how I like it too, less preload and stiffer springs. My preload is all the way out (none) and the .90 give me around 37-38mm rider sag. 100mm oil level sound a bit drastic to me... at 130mm I need to hammer the brakes really hard to bottom out... and still.

Can't wait to see what you come up with...
My preload is almost all the way out, too, with .90 springs with the stock cartridges (GP revalve) with the same amount of sag.

Does spring rate stay the same for the same rider weight regardless of the fork cartridges?

In other words, if I went with AK-20s or Ohlins would I use the same spring rate?

I'm pretty sure I'd need new springs, though, as I think the stock size springs are a different length than aftermarket.
 

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I don't see why the spring rate will change. Preload might be to get to rider sag but I won't change spring rate if you're happy with it.

If you are getting rid of your cartridge with the GP piston kit let me know... might have a buyer.
 

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My preload is almost all the way out, too, with .90 springs with the stock cartridges (GP revalve) with the same amount of sag.

Does spring rate stay the same for the same rider weight regardless of the fork cartridges?

In other words, if I went with AK-20s or Ohlins would I use the same spring rate?

I'm pretty sure I'd need new springs, though, as I think the stock size springs are a different length than aftermarket.
Springs can (and will) vary from setup to setup. The air gap acts as a spring, so the oil height and change in physical volume (of the different cartridges) will affect the air volume. The GP 25 mm cartridges are very supportive and require a much softer spring than a re-springing of the stock forks, for example. I'd go so far as to say that the Traxxion AK kit falls between the GP 25 mm and stock cartridge based on my experience with them.
 

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image.jpg

Today...

I've been working on my settings the past week.

Started off pretty stiff. (Front)
I used the 100mm oil height.
Now I'm down to 125mm....it's starting to take shape.

I'm still wondering about my springs.
Pondering going one size lighter.

This picture is on the brake and hitting a sizable hole.
I know theirs still room to improve.

So much better than stock!
 

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View attachment 14611

Today...

I've been working on my settings the past week.

Started off pretty stiff. (Front)
I used the 100mm oil height.
Now I'm down to 125mm....it's starting to take shape.

I'm still wondering about my springs.
Pondering going one size lighter.

This picture is on the brake and hitting a sizable hole.
I know theirs still room to improve.

So much better than stock!
Look like pretty close. What's your rider sag and preload set at?
 

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Usually about 102mm travel during normal braking.

I went to my roughest local roads to see where my settings were getting me.
Initially I had it set fairly stiff.
I backed off the compression added rebound because it was beating the crap out'a me.
I realize I'm looking for an all-around setting. Stiff it turned well as expected.
Now it's more settled in the rough.....didn't get a chance to check its higher speed manners as I was running out'a daylight.
My goal is to find a happy median.

Enjoying the ride by letting the suspension do its job is my goal.
 

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Will do....

The 102 was under spirited riding on smoother pavement.
Much smoother.

The stuff yesterday was Bump city. But some of my better local roads.

Pretty much I'm testing to see what I've got to play with.

The picture was unintended braking due to hitting the hole.
Like near an off-road excursion. HaHa.....got my heart rate up !!!
 

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We have a lot of that up this way!

This might be obvious to you, but for the sake of others...the idea here is to size the spring and air gap (which again, adds some progressiveness to the overall spring rate) so that you have enough travel to cope with anything you might encounter. You'll know when you bottom out under braking...usually with a good howl from the front tire as it starts to lose traction. Naturally, the spring required to brake hard on the track from 160 mph will be different than what a typical road ride will have.

Ideally, we don't want to bottom out on bumps. This is unavoidable sometimes though, so use caution. The most important requirement is that we have enough travel in reserve to really clamp down on the brakes.
 
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