Have a look on the end of them PJ ones have a number on the bottom front (the bit under the bracket that holds the hoof on) mine have 121 on them I weigh 17 stone and had trouble bending them at first
Jason, poweriSers do not have this, they instead have the batch number in that location. Some do have the bottom weight limit (50, 70 or 90) written on the actual end of the spring though.
yeh they have 332 on i think or do u mean PR70-90 cos thts the weight range and do u know if there easy to fit?
332 will be the batch number.
Springs are quite a doddle to fit...
Basically, undo the long, larger bolt going through the bottom of the hoof, and the one attatching the hoof to the midsection (this will require taking the roller and bushings out). Keep all the parts from these together so you know what goes where. The hoof will then come off the frame.
Then undo the 2 smaller bolts going through the spring on the clip (shown below). The clip will then come away from the spring too.
You have to take the kneebar off to do the next bit, so mark the height it is set at using a black marker pen. Now, take the clip (holding the spring to the top of the frame) off the frame, this will require removing the roller and bushings again. Then undo the clip from the spring in the same way as at the bottom.
Voila, you are left with a single spring with no parts attatched. Now simply reverse the procedure, replacing the new spring for the old one.
On poweriSers these require metric tools, 8mm for the smaller bolts and 12mm for the larger bolts if I remember correctly.I may do a detailed tutorial on stripping down an entire poweriSer somewhen this summer if I have time