PDS shock doc is short on info

Taffy
The principal differences between the Husaberg and the KTM shocks are the clevis and the lean angle. The reduced angle of the Bergs means the shock has less progression than the KTMs. The clevis simply adapts to the swingarm mount configuration of either bike. No great performance difference here. The long needle you describe is used to meter the flow through the rebound circuit and is incorporated in both examples. You don't require a bleed pump in order to successfully service the PDS shocks but you will need a great deal of patience.
Terry Hay

It is vital for all shock absorbers to have an element of compression. The linkage on conventional rear ends is designed to provide progression in both spring force and damping force. The PDS shocks lack significantly in this area. Straight rate springs are certainly an alternative to progressive ones as they will provide a different feel relative to the application. The simple problem with most progressive springs available for the PDS shocks, is that they are indeed, too progressive. An average linkage will provide appr. 30% progression. In other words...the starting ratio for shock shaft versus rear wheel movement may be 3.1mm - 10mm. Final ratio may be 4mm - 10mm. The .9mm change represents the leverage increase provided by the linkage. Just under 30%. Some are higher. Some are lower. A PDS shock experiences a relatively small change due to lean angle. This is approximately 11%. This is inadequate and some form of supplementation is required. The fixed needle due to deisgn constraints is limited to an effective range of appr. the final 30% of travel. When the needle finally comes into play the damping force is rapidly accelerated. Unfortunately there is little progression prior to this event occurring. Combine this with the fact that the bump stop will also come into play in the final travel and you experience a rapid rise in resistive force that can in some instances be quite brutal. I'm not in favour of the latest range of PDS progressive springs and much prefer the old PDS 0 - PDS 4 range. Although I would still prefer to see a spring with a rate increase of appr. 1 kg over the compressive range as opposed to the 2 kg rise we are currently offered. Considering this...A straight rate spring will also not be entirely suitable. The benefit of a straight rate spring will be that of compliance on small to medium bumps. Downside will be poor bottoming resistance. Progressive springs will offer greater bottoming resistance but the rising rate may be less comfortable for trail use.
Terry