Bike setup question

Related:
Create New Tag

12/5/2017 5:07 AM

Having some issues with bike stability. Riding an 09 kx450. Its sprung for my weight.

Im having problems over small chop in 4/5th gear. Bike will bounce off everything and cause headshake down straights. My sag is around 4.5” to try to compensate for the stability issue and i dont want to go any more because thats already well over 110mm.

The forks are lowered in the clamps all the way. & compression is 4 clicks out.
My fork sag looks to be 2-3” or so. I feel like this is a lot and causing the front end to be really low. The low speed damping on them is really soft. So when i want to corner it will turn on a dime.

Not sure where i should go with the clickers or preload settings. I have picked up around 5 seconds over the fall. Wonder if i need a revalve & setup from a company?

|

2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600

12/5/2017 6:13 AM

Email keefer

|

12/5/2017 7:29 AM

Spring fork? Add one step stiffer spring, or some oil. So you can back out on clickers instead.

|

12/5/2017 8:28 AM

More preload will raise the forks in their stroke, so this could be a good start if you feel they are sunk too low in the travel.

4 clicks out is quite stiff. so if your forks are low in the travel this could make them feel harsh. The combination of being low in the stroke and a firm compression setting could be causing your issues... just speculating.

Don't neglect your body position either, being too forward on the bike can create headshake

|

@russ_69

12/5/2017 8:47 AM

RussB wrote:

More preload will raise the forks in their stroke, so this could be a good start if you feel they are sunk too low in the travel.

4 clicks out is quite stiff. so if your forks are low in the travel this could make them feel harsh. The combination of being low in the stroke and a firm compression setting could be causing your issues... just speculating.

Don't neglect your body position either, being too forward on the bike can create headshake

The springs i have are the heaviest racetech offers. Im 250lbs so suspension is a struggle lmao.

I have some preload washers im going to throw in when i rebuild my forks this week and see how that works.

I can basically sit on the rear fender and it still doesnt feel right. It fixes the headshake but then the ass end doesnt feel planted and the front starts bouncing more.

I want to think with more preload on the forks, it will raise the front of the bike up and allow me to soften the damping since there will be more low speed available. then the forks can absorb more of the bump and not bounce around so much. In theory anyways

|

2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600

12/5/2017 2:27 PM

Acid, what is your current spring rates?

|

12/5/2017 4:09 PM

slipdog wrote:

Acid, what is your current spring rates?

Forks are .54
Shock is 6.6

|

2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600

12/5/2017 7:44 PM

That seems to be a very good balance front to rear for your weight. They have been known to give "closest available" and they're not correct for the weight and also not balanced front to rear. Just had that this week and had the customer send the springs back.

Those forks work well between 6-8mm of installed preload, IMO, and check for broken free pistons and leaking lower cartridge seals

|

12/6/2017 3:58 AM

slipdog wrote:

That seems to be a very good balance front to rear for your weight. They have been known to give "closest available" and they're not correct for the weight and also not balanced front to rear. Just had that this week and had the customer send the springs back.

Those forks work well between 6-8mm of installed preload, IMO, and check for broken free pistons and leaking lower cartridge seals

Thanks for the input. Ive got 4 of those preload washers racetech sends with their springs. Im gonna put them in today when i service my forks. Hopefully it helps.

despite stability issues, the bike feels pretty damn balanced when im not going in 4th/5th gear.

|

2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600

12/6/2017 3:59 AM

slipdog wrote:

That seems to be a very good balance front to rear for your weight. They have been known to give "closest available" and they're not correct for the weight and also not balanced front to rear. Just had that this week and had the customer send the springs back.

Those forks work well between 6-8mm of installed preload, IMO, and check for broken free pistons and leaking lower cartridge seals

Thanks for the input. Ive got 4 of those preload washers racetech sends with their springs. Im gonna put them in today when i service my forks. Hopefully it helps.

despite stability issues at high speed, the bike feels pretty damn balanced

|

2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600