Rear suspension

Items are generally accepted for all Husaberg Enduro models.

Also check out Handling and Suspension on UHE.

Shock Manuals

• WP PDS 5018 1999
  Rear shock from '99 onwards

• WP PDS 5018 2003
  Rear shock from '03 onwards

• WP KTM special suspension tools

Rear suspension chart of why!

Check out this advice on your rear shock needs: Rear suspension setup guide.

Rear suspension

!! UNDER CONSTRUCTION !!

About the rear shock

It's very difficult to meddle with the rear shock bar the clickers, spring and preload. The shock needs re-gassing after any work and unlike jap units they have to be done with a special tool so unless you want to go to a bladder, the shock needs charging by a WP specialist. The bladder is considered of equal performance by many to a re-nitrogen-charged standard unit. Fitting a shraeder valve could possibly lead to the chain ripping it out of the reservoir body on G-outs unless it's VERY short!

The code is written on the Spring around it's middle. The 250mm long springs are easy to swap in and out but the 265's are very awkward and need compressing just to uncouple the end cup.

Lightly tighten the preload ring as it can squeeze an internal piston creating wear. Tighten the pinch screw with it facing you so that an allen key can loosen it for making adjustments. It's possible to measure the spring preload in the bike with a tape measure, just get the paddock stand under the belly and the rear wheel free of the ground. This is also the best way to adjust the preload; with the swingarm/wheel dangling off the back of the paddock stand, it should be easy to turn the spring with preload ring all by hand. Each turn of the ring is worth 2mm + - preload.

Setting sag and ride height

'01 and '02s have a race sag of between 85-100mm and a sag of 30-35mm. The '03s+ need 90-105mm. Best place to measure is from the top of the spindle nut to the 'V' inbetween the ducktail and the number plate. Cut a little flat edge into the plastic to help accuracy. Have you checked BOTH heim bearings, if worn, your figures are useless!

Where the rear axle is in the adjustment slot makes a difference to which spring rate is required. Example; your axle is at beginning of slot and you achieve static sag and rider sag with an 84-250 spring if now you had the axle at the end of adjustment slot you would need an 88-250 spring to achieve the same sag. It is the law of mechanical leverage as consequence of that your rebound has also changed (Viking).

Setting up the shock

Firstly set the Correct race sag and the clicks as per manual. Next try the clicks in and out for fun-about 4 clicks per time will let you know.

Try different sag settings for better steering around slow obstacles. Around 90-95mm will give excellent turning response whilst the suspension may have been compromised (I.E it may now feel too stiff). If you have raised or lowered the rear you can go back to 'as was' and keep the change in pitch by raising or lowering the front forks through the triple clamps. So if you raised the rear initially and liked the steering, put it back to 'as was' and instead lower the front to set the bike at the same 'pitch' (raise forks through the clamps).

What does it need?

Generally, if the bike sinks a long, long way at the rear it's a soft spring. A straight rate can fall through it's travel on all pre '06s and feel similar to this. If the bike does a 'whap, whap, whap' at the rear as the bike sinks and rises under hard acceleration in a curve - it's either of these.

If it gives a 'whack' and settles very quickly it may be too stiff. There are two types of compression damping: HSC is for big whallops/G-outs and to stop the bike sinking forever. Until the bike stops sinking you can't really travel forward/open the throttle. This is a classic lack of HSCD. LSCD is for all the small stuff and a lack of it shows in the bike spending too much time with the wheel off the ground.

Rebound is the easiest to describe. This should be backed off and 'added', the worst of 'too little' is that you get catapulted up when climbing a hump at speed, and especially when sat down! Try to stand for these rare occasions and think of the rest of your ride.

So what can we do to them?

We've started with the obvious, the cheap and easy. Set your sags, adjust your clickers. If the Sag numnbers don't add up and you don't have the spring recommended here, maybe that should be next?

If changing the spring you may wish to consider which type of spring to fit. One that gets harder as it compresses or one that remains the same throughout? It's explained below.

Shim stacks are always worth uprating to the very latest spec and indeed after paying 'mucho-expensi-fold' for my shock to be tweaked, all I got was the latest production shim stack.... a lesson learnt.

All pre '06s will benefit from a new needle - especially if riding with a straight rate as it helps stop the shock washing through the travel.

Well, you've got to be keen!!! but there are those that put two primary pistons in instead of a primary and secondary, also, latest tests show a new piston matching a new needle from RT.

Steve McFarland Husaberg.US (Nik: 2005FC550) has done a great deal of trial and error on his bike to achieve improvements. Amongst his changes are to put a shorter '06+ 'bumper stop'. This improved medium bumps as the bumper stop had been coming into effect too soon. Steve has also fitted the larger diameter reservior with it's greater capacity. Again an improvement was noted. The reservior was twisted using offset/eccentric washers for the top heim joint so that the chain would miss the resevoir.

Terry Hay, the Australian suspension tuner likes to fit a 3mm spacer in the shock which keeps the rear end 10mm lower but allows the suspension to work quicker over shorter travel. Again Steve has done this and liked the results.

Shim stack information

Steve supplied us with these shimstacks to ponder!

• WP fork and shock shims stack FC550 2005
• WP shock shims stack FC550 2005 (8.4 N/mm spring)

Bladder v Remote Resevoir?

Tests and graphs carefully done, show the two to be virtually identical. Also those that have tried them back-to-back haven't noticed a difference. Essentially the bladder will fit inside the resevoir and removes the need to recharge the shock. Perfect for those prepared to do their own testing.
For more details check out the article Bladder Verses Piston Arguments in PDS Shock Absorbers. Another unique problem for Husaberg's is that our resevoirs sit over the run of the chain. To use a bladder would put the valve right over the middle of the run of the chain with the consequent damage that may cause on a 'G-out'....

Fitting a schraeder valve

These are the same valves we see when we pump up our car tyres. Check out schrader-valves.co.uk If these are used, the run of the chain may break the valve out of the body on a 'G-out' but one suggestion (as yet untried i believe) is that the schraeder valve be put in on the edge of the resevoir cap. The run of the chain is a clear 1" away. However if you fit a schraeder valve you need to know that when you put 175psi in that it stays in!

This tool does it by unscrewing after the nitrogen is in - to stay!

Staying with the OEM screw

Check out this UHE thread. The recess in the top of the resevoir is slightly tapered which keeps an 'O' ring squeezed 'in' helping to keep a good seal.

WP cap for recharging. Note the T-bar on top for getting to the Allen screw and the ripples in the shock

The pin through goes across a ripple in the resevior

This is a really cool tool from Oz -fair dinkum mate! You can see the large wheel for screwing down the allen screw and the schraeder valve for charging it on the side

Based on the Aussie idea I had a pair of half clamps made	Clamped up!	Note the two screw holes in the top plain	Screw holes in the face, an allen screw 'ready' in the hole and a schraeder valve off to the side

The 'O' ring on the edge can clearly be seen. The brass centre moves back	Not aesthetically pleasing but does the job!	The T-bar on top pushes down and screws flat into the top of the resevior

Polish the inside of the reservior

Steve McFarland (2005FC550) felt the difference when he did this to his bike!

KTM and Husaberg - shock angle

Unlike the forks, the angles of the respective rear shocks are different. The KTM shock is layed forwards whilst the Husaberg's are upright. This forward angle means that initial small bumps on the KTM are harder to control but later in the stroke they're better than the Husaberg. The opposite is true for the Husey. Word has it that in general, we got the better deal!

Bleeding the shock

The oil contains minute air bubbles that must be purged. There are several ways to do this. There is naturally which allows air to find it's way to the compression screw exit. There is vacuum which actually creates a suction trying to draw the oil out using air. This actually makes the minute air bubbles larger and they head for the exit even quicker! Finally there is force which drives oil through the shock - oil that is clear of any air.

Keep feeding down and in, just agitate for good results! (Khan Cross)	Shock set fair to be agitated at the shaft to help air and oil swap (Khan Cross)	Stick this bleed bottle in the screw hole near the comp clicker and agitate. Excellent results apparently! (Husky510)

Bleedpump. The chamber is for creating a vacuum NOT for pressure. (Drehwurm)

The pipe on the right, er, well it er! Look take it from me. It works! (Drehwurm)

All parts available in kit form!!!! Ask Drehwurm...	Huge cap and pressure guage	The two-way valve can be seen

Note green vacuum pump behind and shock held in the extended position (Folie)

KTM shocks (breifly and vaguely!)

About the rezzys; early style prior to '02 is small diameter long length, '03/'04 are large diameter longer length, and '05 and later are large diameter shorter length.'02 and earlier have no negative springs, '03/'04 have negative springs, '05 and after have no negative springs. '98 series uses a long needle, '99 through to '02 use a very short needle (bottoming control), '03 is slightly longer with each later year longer still but no where near the '98 version. Early dampers,'01 and prior have a weak clevis and also have seen the upper ends of the body fail. On a KTM, the '03/'04 compression adjuster and body in that area is sometimes worn through from the riders boot causing a leak. '05 and later have the rezzy indexed slightly differently to prevent this. As for internals, there are several key points; '05 and later shafts and needles must be used in sets, late style needle with late style shaft etc. '02 through '04 style will work together (and possibly as early as 99). Early style dampers prior to '03 used the same piston for each position, however they were changed in 2000(?). The '03/'04 series uses different but similar pistons for #1 and #2 and the '05 and later use completely different pistons for #1 and #2. Why do tuners recommend a piston swap? Mainly for the '05 and later style damper. Use the aftermarket piston in #1 position and move the OEM #1 into #2. The alternative is to run an '04 and prior #2 which is the same as the #1 and #2 from 2000(?) through 2002 (This is from PMK at K-talk - cheers mate!).

2005 FC550, KTM PDS rear shock.

Factory shock

(Makke)	(Makke)	(Makke)

Needles

The needle is there to block the movement of fluid and the design is such that it fills the hole more and more the deeper into the stroke you go. OEM needles from '06+ have been designed for the straight rate spring and heavily dampen the end of the stroke. One of our members had trouble with a Race-Tech version, however others have been OK and Terry Hay has managed to get a material change for the RT team.

Progressive (dual rate) or Straight-Rate?

Ah! the dilemma! The jury is out on this one and if you follow the detective story you'll see that infact there are two outcomes we can persue here. First of all, until '06 the shock damping was set for a progressive but didn't stop 'blowing through' on big bumps despite the spring getting 'stronger' at the end of the stroke. Now though the rear damping is set for a straight rate and is very heavily damped at the end of the stroke. The straight rate spring on pre '06 bikes is nice on the small and medium bumps but alas blows through on bigger stuff. A progressive spring can seem hard on medium bumps as the secondary 'weight' stops the shock earlier in the stroke than is desired. This problem is known to the top tuners and the ideal answer is for the progressive part of the spring to be delayed in an ideal world.

The Straight rate spring is best with the correct needle and shim stack fitted to stop this 'blowing through' (so that's '06 and onwards then ok?) whilst the progressive spring is a good stand alone item. Fitting a progressive spring to the latest straight rate needle and it's stronger end of stroke damping could be good especially for the heavier rider because there are two things stopping the shock blowing through, and you could then back the valving and the preload off to soften for light bumps. Unfortunately, WP stop at a 8.5/11.1 which is light and other manufacturers of 'progressives' are sought such as Factory Connections; 9.0/11.5.

PDS spring codes

To understand the codes on a PDS spring: "76/90 250" means that the spring has a 7.6 start and 9.0 finishing weight. Rate 1@20mm of deflection. Rate 2 @100mm deflection. That's why it's called a progressive spring. 250 means 250mm free length.

There are now several after market springs available for the bigger rider. Factory Connection do a 9.0 -11.0 and John F3 (at 220LB) loves it. Word has it that the Race Tech spring comes on too hard too soon....

The above recommendations are from riders who have adjusted the damping to suit the spring.

However, expert rider Moto520 from K-talk did some extensive testing on many, many springs and says "The 260 mm lenghth spring had a better transition point from super plushness to firming up from midway on down. In other words a more gradual increase. The shorter springs had a spiky reading and got stiff sooner". Further he mentions how the 250's bow out at the sides and this can be inflammed by the spring not being flush across the ends but instead bowed, bent or rippled.

Straight Rate codes

Said to have better Mid suspension properties than the PDS but it does fall through on big jumps. The WP springs generally move up in 0.2 increments. So an 8.0Kg is followed by an 8.2Kg etc, all the way to 9.0Kg which is the largest WP do. However K-Tech in the UK claim to have springs manufactured by the same company and go all the way to 10.0Kg in 0.50Kg increments. Funny how it's not in 0.2s given they're the same factory?......

Figures for rider naked! (approximate):

Bleed the shock

There is a lot of information on ktmtalk.com of how to do this. Here are some photos of the various tools used to bleed air from the oil. There are three ways of removing air from the oil. Firstly, you can agitate and decant the shock in order to dislodge the bubbles and Terry Hay says that this is good enough if done well, secondly, you can create a vacuum that sucks on the oil and makes the air bubbles larger(around 10"hg). The other way is to create a vacuum pump that works at This way they rise and leave and the job is done quicker. Thirdly, you can drive oil through using the HSCD bleed hole as the exit and this will then have to be carefully fitted afterwards.

Recharge the shock

Yes you can. There are several lads that have made a simple unit to do this. A gas cannister including pressure guage, a 90 degree on/off tap,a pressure guage for what's in the unit and then the difficult bit - the 'lip' that sits on the shock body.

Bleedpump equipment	Bleedpump fiting

Lower heim bearing

Needs to be stripped and greased mid season or expensive to replace. Tighten the preload collar to the recommended setting or it will wear out the piston inside (squeezed body). The upper heim needs greasing once per season. The upper heims go eventually even though they see less muck.

Swing arm slack

Play in the needle rollers and pin. Here try industrial hardened steel rod. Found .4mm more pin diameter and still fitted. Later models improved with far wider oil seals on the needle rollers to keep the water out. I found that oiling instead of greasing the needle rollers vastly improved service life. See this UHE Forum Thread

Handy Tools

Rebound Adjuster Screwdriver (Viking)