Setting Sag On 520 EXC

[Kwi-Chang]

I am looking to find info on setting the sag on a 2002 520 EXC. I have looked in the manual, searched the forums here and MX-Tech's site as well but no luck. I know what to do but not sure where the measurement should be taken from & to. I have also heard that KTM's use a different means of determining sag.

Anyone?

 

[Shaw520]

I measure from the center of the rear axle, to the center of the seat bolt.
Lift up on the rear of bike to unload the shock, then let the bike settle down under it's own weight. Measure. Then sit on the bike in ridding/attack position, have someone hold you up, while someone else takes the measurement again. Should be between 90-95mm or 3-4 inches less then your first measurement. Adjust compression ring accordingly. This is called 'race sag'.
Now to check static sag, once again, unload the rear of the bike to is full extension, hold it there while somone measures, then let the bike settle down on its own weight, measure again, this should be 30-35mm or about an inch. If it is less than that, you need a stiffer spring, if it is more than 35mm, you need less spring rate (which is highly unlikely, unless you weigh 150 pnds).

 

[Kwi-Chang]

Thanks Shaw520 - I am in the 200-205 lb with gear so I'm hoping the stock spring will be fine.

 

[jeb]

The stock springs on both ends are too soft for you. I weigh the same as you do. I use .46's ( .42's are stock) up front but .44's would work, too. I use a PDS3 in back. The suspension will not work correctly unless you get the right springs in there.

Set your rider sag at 95-100mm. The static sag should be 25mm +/- 10mm.

 

[Kwi-Chang]

Hi Jeb - Do you think that I need to go stiffer on the springs if most of my riding is single track, mountain terrain and for sure *not* at race speeds? I am a 40 something and a decent rider but certainly slower now. Maybe stiffer springs and softer seat is the ticket!

Kwi

 

[John 300 EXC]

KC, I'm also 200#. I have used a PDS-4 & 8; I like a heavy rear spring with less preload than possible on the PDS-2 or 3. On the forks of an '01 & '02 520, I have been happy with the stock spring, but higher fork oil level. Stock, both bikes had air chambers of 160-165 mm (very soft), I added oil to decrease air chamber to 125-130 mm. I have soft, tall seat foam, which makes the rear end of the bike much more pleasant than the stock seat.

 

[Kwi-Chang]

Here we go again!

I told my wife that "Hey, if I buy a KTM... it has all the good parts on it and so I won't need to spend anymore money on it - unlike the KDX which needed some help & $ to make it into a truly worthy woods machine. So you & the kids will see a lot more of me since I won't be working on the bike so much!"

So help me out with some good excuses...err...reasons that I need to spend more money on an already expensive toy. At least I can still afford to set the sag properly. (or can I?)

Kwi

 

[Kwi-Chang]

J-3K - what seat did you get? Are you happy with it?

 

[John 300 EXC]

KC
I have used the same tall soft foam on my last 3 KTMs, I could not ride any distance without it. I have made plenty of 100 mile days, racing and dual sport, without any problems. I can't remember where I got the seat, but it's a great modification that relieves a LOT of pain.

 

[Kwi-Chang]

I am heading to SE Utah for a 10 day ride and I'm thinking that a change of seat would be good *before* the trip. For now I'll get a pair of padded shorts and do some research on the seats when I get back - hopefully I won't get a permanent injury from that brick KTM calls a seat in the meantime...