2002 520 sx fork problems

[fairdinkum]

front end does not soak up high speed hit,deflects off wash outs.have changed oil height to 125ml and the valve stack is a single stage,would it be better with a dual stage- what shims as i have all the shims and can do the job....cheers

 

[marcusgunby]

Not many people like to give out shim stacks im afraid.I have heard the 520 works well with 15mm of preload on the forks-i know this sounds alot but it really works.

 

[Yoken]

I have purchased the 2002 KTM520SX 3 weeks ago, so I do not have many hours of testing on it. As you mention, fork deflection was a problem for me too. At this stage (after 5 hours of riding only), the best setting I found are:

FORK
Oil type: unchanged so far
Spring rate: stock
Internal preload: stock plastic spacers
External preload: 1 turn IN
Oil height: 85mm to have decent bottoming resistance (but it makes the fork a bit harsh on the last third of the travel though...)
LSC: 26 OUT
LSR: 15 OUT

SHOCK
Spring: stock
Spring preload: set for 95mm rear sag (standing on pegs)
LSC: 17 OUT
HSC: full OUT
LSR: 25 OUT

Please note that I am 1m80 and 80 to 85kg with gear. And I tested the bike only on rocky hardpacked clay.

The above settings gave me a much plusher ride and a quite good control in tight slippery turns. Less deflection definitely. I still have some headshake at speed when entering breaking bumps though...

For info, during my next rides, I will try the following:
- slight increase of LSR (1 click at a time) to compensate for the high oil level. The fork rebounds at bit fast when I reach near bottoming in breaking bumps.
- step by step increase of external preload and opening of the LSC. Just to see if I can keep it plush with better bottoming resistance. I will see also how it affects the headshake problem.
- move the rear wheel all the way back and see about the headshake. I will try also moving the handlebar to its 1st position (closer to the gas tank)...
- step by step increase the shock HSC and see how it affects the handling...

Hope this will help you and enjoy your riding.
Yoken.