KDX 200 deflecting on rocks/bumps

g123

Member
Apr 3, 2008
3
0
Hi,

I have an 04 KDX 200 which I've just had the suspension fully done on (gold valves, new springs, reshimmed). It feels way better with the suspension done but I'm having issues with the front wheel deflecting on rocks (approx fist sized and a bit bigger) and bumps/ruts. My dad has an 06 wr450f which I can fly along on with no fear of deflection. However when I hop back on mine it feels loose and twitchy.

I've lowered the forks in the triple clamps so they are flush at the top and adjusted my bars forward a bit which has helped. Currently the bike has a Michelin Starcross MS3 on the front and a Metzler Motocross MC4 on the back. Normally run about 11 to 12 psi in both ends.

Would a steering damper help? If so how have other KDX owners found them? (I have searched).

Is it even possible for the KDX to sail across everything without a thought like the WR does? Or is that the limitations of a dated 200cc 2 stroke vs a modern 450cc 4 stroke?

Thanks,
Glen
 

John Harris

Member
Apr 15, 2002
552
0
Steering damper will help, wer makes one to easily fit and others are available. However, you are dealing with dated suspension (at least 10 years old) on a lighter bike. It just will not handle as good as a new one! Ride safe John
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
3
A damper will help for sure.

Even after the revalve, you may have too much high speed compression damping for the rocks and roots. If you revalved yourself using RT's guidelines, this may be the problem. For lots of rocks and roots you are better off with less high speed damping, IMO.

The more modern suspension components are an advantage on the newer bikes, but it sounds like yours can be made to work better than it is now.
 

ebeck

Member
Dec 13, 2006
199
0
Is it even possible for the KDX to sail across everything without a thought like the WR does? Or is that the limitations of a dated 200cc 2 stroke vs a modern 450cc 4 stroke?


It is not a limitation of the engine it is a limitation of the suspension. KTM makes an 2008 200cc off road competition bike. Being a 2 stroke does not date the suspension the suspension dates the suspension.

Definitly play with the clickers and if you have the time and patience you cna learn to fiddle with the internals and oil weight to help correct things. Ultimatly it will never be perfect. there is a reason they loaded it with real light springs from the start.

If the suspension is becoming a liability consider putting on KX/CR/YZ/WR/RM suspension. That is actually pretty easy.

There is just no way to take 20 year old suspension technology and make it as good a MX suspension was even 10 years ago. Valving and springs on the old suspension can have effects that are unintended and can often not work as well as one hoped.

Here is what I did. I made 2 KX/KDX Hybrids. All the benifits of the really great KDX motor with all the benifits of the MX cousin. It is even better than you can imagine. One 02 and one 03. :nod:

picture001mediumhs2.jpg


picture013mediumey2.jpg
 

g123

Member
Apr 3, 2008
3
0
Any lower than 12psi in rocks and isn't there a good chance of denting rims/pinching the tube?

The rear sag has been set and is the 'D942FA' a Dunlop and are you running that on both ends?

The ride isn't harsh infact it's nice and plush - it just wants to flick the bars around when I come across rocks or rutty ground. Also, the suspension was modified and setup by a fairly experienced suspension mechanic (didn't do it myself I mean).

Nice hybrids BTW and I understand that the 'suspension is the limitation of the suspension' I just thought maybe a light, flickable 200 2 stroke handles certain types of terrain quite differently than a heavier, slower turning 450 4 stroke.

With the correct suspension setup how close can I get it to the WR's feel of flying through rocks without a care? Or am I flogging a dead horse in that respect?

Thanks for all the comments,
Glen
 

250RDude

Member
Feb 23, 2003
75
0
I run a Scotts Damper & Tripleclamp on my 97 KDX200. I can't tell you how many times it has saved my Arse in the Rocks & Sandwashs here in AZ. It's all stock suspension except for the damper & heavier Racetech springs up front. Race Sag set & clickers backed way out. Soft & plush & hardly any deflection on the gnarliest of boulder sections. The front will bottom on G-outs but I'll deal with that considering 90% of my riding is on ST. Dunlop 739 up front at 13 PSI & Dunlop D952 out back at 11 PSI.


Sycamore3-16-08.jpg
 

Green Hornet

Member
Apr 2, 2005
837
0
A D942FA Front/D756 Rear. I run an HD Tube in the front/Rear & run 10.5-11psi(MAX). Without an HD tube you will get a pinch flat at some point. Keep the front light in the rocks. You should try the D942FA it's like a pillow on the front wheel....Its what works for you that matters though...
 

hart125

Member
Dec 11, 2003
46
0
another opinion

High speed compression is too stiff.. Do you know what the shim stack is set at on your gold valves? My bike at about 60 mph on bumpy rocky trails will through me all over the place. but if i lower my high speed compression my forks will bottom when I pound through mx style woops.. You can't have best of both worlds. If your not doing fast large obstacles I'd say drop your high speed compression but get ready for bottoming if your hitting hard large obstacles at like a race speed. If I stop racing my kdx I will drop the high speed compression immediately!

if the wr doesn't have a damper you should be able to get your suspension close if you have the gold valves. Tires might help too but I'm thinking its a valving problem.
 

g123

Member
Apr 3, 2008
3
0
I fiddled with the compression adjustments on the bottom of the forks and backed it out 4 clicks on both sides which made a noticeable difference. Weird thing was that stock the forks are supposed to have 16 clicks of adjustment but when I went all the way out and all the way in there seemed to be 22 clicks? How does that work?

Also should I back the rear compression off as well?

To be honest I'm not sure what he did to the suspension - it feels alot better but I'm not sure if it was worth all the money. Seems a bit overkill for my skill level/type of riding. Oh well - easy to be wise after the event.

Thanks for all the suggestions,
Glen
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
3
g123 said:
Weird thing was that stock the forks are supposed to have 16 clicks of adjustment but when I went all the way out and all the way in there seemed to be 22 clicks? How does that work?

Also should I back the rear compression off as well?

Maybe only the first 16 clicks out make any difference. The valving may be full open after 16. FWIW, each additional click out makes a smaller difference. The difference between 1 click out and 2 clicks out is large, but the difference between 15 and 16 is almost un-noticeable.

Excessive high speed compression damping (and too soft springs) on the fork is common on KDXs. The rear shocks do not usually have way too much high speed compression damping.
 

hart125

Member
Dec 11, 2003
46
0
What I'm talking about is an actual inside adjustment. the screw your turning is the external low speed adjustment. if you wan't to really change your high speed you have to pull the forks apart and mess with the shim stack. the gold valve has actual high speed and low speed adjustments where the stock has only an overall shim stack. thats the value of the gold valve! its got better size holes and shims to control different speeds of oil flow.
You will only notice a little difference with high speed obstacles when you change the screw adjustment in the bottom of the fork.
 
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