GasGas GP300 KYB Fork Stiction Issue

[VintagePhill]

Hi Guys!
I am having a bit of trouble with my KYB Forks on my GP Edition.
My Dad recently got a 390 Beta 2022, which also uses the Kayaba 48mm Suspension. While testing his new Bike I noticed that his Forks had absolutely no stiction while riding.
The slightest compression while sitting on the Beta compresses the forks extremely smooth. Sadly thats not the Case for the GasGas Forks. The Stiction under load (while sitting on the Bike) is quite high. You need to really try to compress the forks to get them to move.

I tested this further by removing the forks of both bikes.
Using my own bodyweight to compress the forks I feel no difference in terms of stiction between the different forks.

But if i apply a Sideload (not only pushing vertically, but trying to "bend" the Fork while compression) my Forks start to stick like crazy...

Things I have already done:

• Changed Seals and Bushings (OEM Kayaba)
• Used new Oil (300ccm 2.5W)
• Bled the inner cartridge( with new oil)
• aligned the forks while tightening the Axle (I even tested without tightening the Axle and retaining bolts - no improvement)
• used lower than specified Torque for the Triple Clamp (10Nm instead of 13Nm and 17Nm)
• Used silicone oil and Spray to treat the Seals (very slight improvement for 1 Ride)

Because the Bike is the GP-Edition I have the DLC Coating on my Kayaba, which the Beta doesn't have. The coating looks good and should counter the mentioned stiction as far as i know?

Do you Guys have any additional Ideas that I could try?

 

[(F5)]

My list in my head was less than you've already done. Good luck.

 

[Anders]

Hi Guys!

Using my own bodyweight to compress the forks I feel no difference in terms of stiction between the different forks.

But if i apply a Sideload (not only pushing vertically, but trying to "bend" the Fork while compression) my Forks start to stick like crazy...

...
Do you Guys have any additional Ideas that I could try?

In a way, I think you give yourself a hint to what to look for here. As there is stiction with even slight sideways load, that has to mean something. Perhaps the bushings are a tad too tight? You could (using e.g. a lathe) to make them slightly thinner (remove some material from the rear), and possibly also try to make some provisions for the bushings to move slightly to follow the sideways / bending movement of the leg.

I'm just guessing here, but I think that is what I would have done.

 

[gasgasman]

Triple clamps may be tweaked.

 

[VintagePhill]

Thanks for the Tips, sorry for responding that late. I was on a Weekend Enduro Trip and had hoped the suspension would maybe break-in. But no, its sticks like before I rebuilt it.

Triple clamps may be tweaked.

I tested the forks after installing the new bushings and Seals. The Forks weren't even mounted in the Bike. My Bodyweight and the mentioned Sideload were enough to bind up the Forks....

This week I will try some new Forkoil, and also slightly cross hatching my fork tubes. I will post the results!

 

[coopernicus]

I have a 2018 GP 300 and it has what feels to be more stiction than the other non-GP 2018 and 2019 GGs that I ride with (there are 3 of those in our riding group). In my opinion, my front end is more controlled for the majority of riding we do here in Colorado. Those that have ridden my bike prefer it to theirs(regarding control) even with heavier springs and SKF seals. Where it lacks to a "standard" 2018-19 EC is in "washboard" conditions on our heavily used dirt roads connecting trails. It's possible that this "feel" is intentional to give as much feedback to the rider as possible. When I ride a non-GP 2018-19, I find the front end easily moves up and down giving a vague steering feel that hinders steering precision. These are just my opinions as a former "A" class offroad racer who is now old and likes to trail ride!

Eric