KTM (WP) – Shock and Fork Service In this case for a KTM sx-f 250 2006. Most of this thread should apply to the 250-450’s for years 2005-2009 (don’t quote me on that) Just thought I would send out a post to perhaps help others who are inclined to service their own suspension. Personally I have never owned a KTM steed. This recent effort was to help out a buddy who picked up a 2006 sx-f. When he got it home the first thing I noticed was general care and maintenance on this bike was for not. In my experience when an add says “never raced” – usually means something far worse = Never properly serviced or maintained. A fate much worse than being flogged at the local race track. Second was the back shock was shot and leaking oil. Being that I love wrenching I said I would sort out the back shock. 25hrs or so later, and a complete tear down. The bike looks new again. Here are my learning’s, tip and relevant links that took hours to find. Shock: Basic step by step A good step by step form “ADVrider”: by Tseta http://www.advrider.com/forums/showthread.php?t=653302 notes: shock was similar, other than the rebound section. Service manual links: (this is the manual that supported the shock I was servicing) http://slorider.com/ktm/manuals/wp5018pds2003.pdf Schrader valve mod: Again WP coming up with an elaborate tool to ensure you have no choice but to get it serviced by your local KTM dealer at a less than kind price. Suffice it to say modifying the “piggyback” cap took less than 10 min and cost 2 dollars. Step 1: Buy a NPT (Schrader valve) Step 2: Drill out cap (11/32 drill bit which is standard for NPT valves) Step 3: Tap using a standard NPT tap As you can see it comes out pretty clean and easy. As an alternative you can also use this from racetech: http://www.rockymountainatvmc.com/p/44/54/280/1066/4149/5854/Race-Tech-KTM-Bladder-Cap-Kit Shock Oil: Again KTM or WP being bastards by charging double per liter for their shock oil. Thus, I obviously look at alternatives. I have been using Peter Verdone Designs web site for years for my MTN bike suspension. I cannot thank this guy enough for his chart on comparing various oils. http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid In this case, WP uses fairly thin oil than others. I used Maxima 3wt for both the shock and the Forks. Purging air bubbles: Another stoooped tool KTM insists on that is not necessarily required and can easily be replaced by gravity and patience. Best part on this video is at the 13min mark. Rebound Adjuster: While I’m bitching about things; WP came up with the worst piece of engineering that I have seen in a long time. See pic – now I will give you 1 guess where that sucker is going to snap if it goes to the stop or gets corroded into place – which btw is often. So much so you can get a mod to prevent such a thing. In my case I just added some Teflon tape to the retaining nut that secures the adjuster in place. Charging the Piggy Back; Not to start a war here but air vs Nitrogen. I completely understand the merits of charging with nitrogen. It’s an inert gas that does not contain moisture and is not as subject to change by heat as air can be. Personally if you can get it charged for a few bucks at your local auto stop – sure go ahead. If you could not be bothered air is fine in my books. Never been an issue on my mtn bike units. Other than that slap it all back together and it’s good to go. Forks: For the most part same as other brands to work on. The only thing I struggled to find was the oil level – which is set at 100mm (thanks to frezno) from the top of the fork tube compressed all the way down on the stanchion, compression rod in place and spring out.