View Single Post
Old 09-25-2012, 07:31 AM   #122
Beastly Adventurer
Joined: Nov 2006
Location: On a RTW ride - currently SE Asia on the way to OZ
Oddometer: 5,426
Originally Posted by Clay Spinner View Post
Just came across the below blurb about setting up the WP forks. I'm hoping to make the same change in the future and thought it may interesting to someone...I've put the interesting bit in Bold and italic typeface.

For hardcore racing, we ran this setup on the 2012 KTM 250SX (stock specs are in parentheses).
Spring rate: 0.46 kg/mm
Oil height: 370cc (380cc)
Compression: 7 clicks out (12 out)
Rebound: 12 clicks out
Fork-leg height: 5mm up (flush on a sandy track)
Notes: The cheapest way to fine-tune the KTMís WP forks is to raise and lower the fork-oil height to get the smoothest midstroke action without bottoming, which is why we lowered the oil height by 10cc. KTMís forks come with different oil heights for each model. The 125SX and 150SX have their oil set at 360cc, the 250SX has 380cc, and the four-strokes roll out of the factory with 390cc.

For hardcore racing, we ran this setup on the 2013 KTM 250SX (stock specs are in parentheses).
Spring rate: 5.4 kg/mm
Race sag: 105mm
Hi-compression: 2 turns out
Lo-compression: 15 clicks out
Rebound: 12 clicks out
Notes: We ran a 1.25mm-longer Pro Circuit shock linkage. Not only did it lower the rear of the bike by 10mm, but it stiffened up the initial part of the shockís stroke to help widen the range of the stock 5.4 shock spring. Faster or heavier riders might be required to go to the stiffer 5.7 kg/mm shock spring. If you are savvy, you will use free sag to make the decision for you.
Not sure what exactly is interesting about that, unless there is anybody that didn't know that changing fork oil level will also affect the fork action?

The specific numbers you are listing are completely irrelevant to anybody but that exact rider/bike/forks. For example, he is measuring ccs because they use closed cartridge forks on the modern KTM motocross bikes. On an open cartridge fork which pretty much everybody uses on their airhead conversion you tune by measuring air gap with the springs removed and not by measuring oil volume inside the cartridge.
Currently going RTW on a KTM 690 Rally, trip blog:

LukasM is offline   Reply With Quote