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17' KX450F Front Suspension Struggles - Traction Issues

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Hey guys,

First post here. 

 

I've just picked up a new 17' 450F and seem to be struggling a little with the SFF air TAC fork, I've spent hours researching them on these forums and have got the fork set up fairly well, I would say it's 90% there. 

 

The fork feels nice and plush and is working how I would like, however, I'm having issues with the front end traction. I live out in the UAE so all I really ride is dunes/baja style desert circuits and I don't have any confidence in the front end at the moment. Coming off a Honda I use to be able to throw that thing into the flat desert turns and the front would just grip allowing me to power round, but with the Kawasaki it feels like it's riding on the edge of traction and just wants to wash out, it also feels a little twitchy at high speed.

 

I've got about 5 hours on the bike now and these are the settings I'm running, I'm roughly 210-212lb geared up and have my sag set at 105mm:

 

Inner = 167psi

Outer = 16.7psi

Balance = 200psi

Compression = 12 back

Rebound = 11 back

 

Any help on this would be really appreciated, cheers guys.

Jordan

Edited by Bickers

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What is your sag?  At 108, my bike pushes real bad but at 104 it turns like a cat on carpet.  I have kit spring forks on mine so not exactly apples to apples but sag is a key component to front end traction.

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What is your sag?  At 108, my bike pushes real bad but at 104 it turns like a cat on carpet.  I have kit spring forks on mine so not exactly apples to apples but sag is a key component to front end traction.


Hey mate, I have the sag set at 105.. that seemed to be the general number I came across when setting it for the 16-17's.. I'm yet to check my free sag to see if I'm too heavy for the spring so if sag is effecting your turning then that could potentially be why?

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I know they changed the valving on the 17s. But that seems like and awfully low inner pressure combined with a high balance chamber. Maybe the high outer pressure will hold the fork up but it won't start soon enough to keep it from sagging way too much. Personally I would have zero in the outer and use your inner and balance chamber. The outer seems to make it very harsh.

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3 hours ago, Bickers said:

 


Hey mate, I have the sag set at 105.. that seemed to be the general number I came across when setting it for the 16-17's.. I'm yet to check my free sag to see if I'm too heavy for the spring so if sag is effecting your turning then that could potentially be why?

 

The free sag shouldn't effect it much.  That's mainly to see if you have the right spring.  Assuming the tire suits your conditions, the reason a bike pushes is most often caused by the forks being too stiff, the shock being too soft, the sag being too much or the forks being too low in the clamps.   There are other issues that can cause it like poorly designed clamps or pull rods but the Kawi doesn't suffer from any of those issues so your problem probably lies in one of the original 4 things I suggested above (3 actually since you said your sag is 105).  If it were me, I would try pressures in the 178/10/210 region and see if that plants the front end a little better.  If not, try raising the forks a few mm in the clamps.  Also, take a close look at your shock settings.  If it's squatting too much in the back, it can have the same effect as too much sag.    

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18 hours ago, gscx said:

I know they changed the valving on the 17s. But that seems like and awfully low inner pressure combined with a high balance chamber. Maybe the high outer pressure will hold the fork up but it won't start soon enough to keep it from sagging way too much. Personally I would have zero in the outer and use your inner and balance chamber. The outer seems to make it very harsh.

Hey mate, the settings I'm running now are mainly based off the recommended hard settings in the manual and just tweaked a bit based on what I have read on the forums. The base setting classed as hard are as follows:

 

Inner - 167, outer - 16.7, balance - 189

 

 I added pressure to the balance to soften the initial feel and lower the front height a little, however I'm defiantly going to try running the outer much lower and the inner higher as suggested to see how it feels, thanks.

 

16 hours ago, Endoair said:

The free sag shouldn't effect it much.  That's mainly to see if you have the right spring.  Assuming the tire suits your conditions, the reason a bike pushes is most often caused by the forks being too stiff, the shock being too soft, the sag being too much or the forks being too low in the clamps.   There are other issues that can cause it like poorly designed clamps or pull rods but the Kawi doesn't suffer from any of those issues so your problem probably lies in one of the original 4 things I suggested above (3 actually since you said your sag is 105).  If it were me, I would try pressures in the 178/10/210 region and see if that plants the front end a little better.  If not, try raising the forks a few mm in the clamps.  Also, take a close look at your shock settings.  If it's squatting too much in the back, it can have the same effect as too much sag.    

 

Thanks for the info man, really appreciate it and thanks for the recommended pressures - I'm going to try them out when I'm next out on a ride. I have a feeling the shock may be a little soft as I backed off the clickers initially so I'll stiffen the shock up, run what you've suggested and see how it feels. 

 

Cheers

J

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Regardless on inner, i find the bike corners the best with 15-18psi higher in the balance than the inner. So if you're running 165 inner, try 180 in the balance. And if your not casing or over shooting big jumps and find that bottoming is an issue, run a lower outer pressure. Try 10psi. Some super smooth guys on smooth non supercross style tracks run as low as 0psi in the outer. 

Edited by chadw90

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5 hours ago, skorpan777 said:

I don't have the 17 but I read somewhere. (think it was MXA) that it matters in which order you pump up the  fork

Yes. Inner, outer and then balance. If you dont have the Works Connection No Loss Air Adapter, I suggest getting one. I found before the adaptor i was losing 8psi on my balance, 5psi on inner and nothing noticeable on outer when disconnecting the pump. 

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Then why not just add a couple lbs extra and call it good?

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4 hours ago, gscx said:

Then why not just add a couple lbs extra and call it good?

Not a very precise way when trying to achieve the perfect setup. If as little as 1 or 2 psi can make a noticeable change, then just adding a couple more psi isnt really helping you. It would be the same difference as setting sag with no gear and giving the spring a couple extra cranks to make up for not having gear on. It will get you close, but not exact. When we are talking about making bikes handle to their full potential, we need to be exact

 

Edited by chadw90

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On 6/10/2017 at 5:37 AM, Endoair said:

The free sag shouldn't effect it much.  That's mainly to see if you have the right spring.  Assuming the tire suits your conditions, the reason a bike pushes is most often caused by the forks being too stiff, the shock being too soft, the sag being too much or the forks being too low in the clamps.   There are other issues that can cause it like poorly designed clamps or pull rods but the Kawi doesn't suffer from any of those issues so your problem probably lies in one of the original 4 things I suggested above (3 actually since you said your sag is 105).  If it were me, I would try pressures in the 178/10/210 region and see if that plants the front end a little better.  If not, try raising the forks a few mm in the clamps.  Also, take a close look at your shock settings.  If it's squatting too much in the back, it can have the same effect as too much sag.    

Hey man,

Tried out the pressures you advised this morning, worked a treat - The front end felt planted and the suspension felt really good so thanks for sending those numbers through! 

The only thing now to do with the suspension is sort out the high speed twitchiness, would you say this is due to rear shock settings?

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Just don't think that you daily in the feel touch with air. 

Use MXA recommended air settings then daily in the feel with clickers. 

Just see the air as a spring. Ive seen many tried to set it up just with the air and forget to use the clickers. 

Thats my 2cents 

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6 hours ago, Bickers said:

Hey man,

Tried out the pressures you advised this morning, worked a treat - The front end felt planted and the suspension felt really good so thanks for sending those numbers through! 

The only thing now to do with the suspension is sort out the high speed twitchiness, would you say this is due to rear shock settings?

Where are you feeling the twitchiness?  Are the handlebars jumping around in your hands or is the back of the bike dancing side to side on you?

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Where are you feeling the twitchiness?  Are the handlebars jumping around in your hands or is the back of the bike dancing side to side on you?


It's towards the back, it's not too twitchy but I can feel the back hopping around and I'd say it's mainly when in 5th giving it the beans.

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Just now, Bickers said:

 


It's towards the back, it's not too twitchy but I can feel the back hopping around and I'd say it's mainly when in 5th giving it the beans.

 

The safest answer is to feed it fewer beans but there goes all of your fun  HAHAHAHA  I would start with opening up the HS compression on the shock (where is it set to now?).  I'm strictly moto but I run mine at 2.75 turns out C-12 R-10.  That softened up the rear nicely.  The other thing to check is your free sag.  In this instance, it does kind of matter.  You might be at 105 race sag but if your free sag is less than 25mm or so, the spring could feel extra lively in this scenario.  I have a spring that is maybe on the "too stiff" side for me so I can run a little extra free sag.  It gives it a bit of a dead feeling but I like it that way.  

 

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On 6/24/2017 at 10:14 PM, lewisb13 said:

What air pressure are you running in your front tire?

10PSI in the front.

 

The pressures recommended above by endoair worked great and the front is gripping how I would like it too.

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Hey,

  what is your weight?  I find running any pressure in the outer chamber gives a harsh feel. what are your fork pressures at now? and where is the shock hish speed compression set to?

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