Ah CBY, i've seen the rabbit! You are of course quite right in that a cut spring does indeed carry a greater load yet in standard linear spring ratings each inch compressed carries the same load but an engaged or under compression spring is carrying load and thus pressure whereas one that is just approximating its fitting space at rest or static load, this has no force pressing upwards against the main spring so although the springs appear to be in series they are in fact in parallel. as each spring has a separate load effect. if the rebound spring in this case of which we speak under static load were applying force against the upper main spring the force of the two springs would provide the total spring rating of the suspension. so by using this adjustment of a shorter rebound spring giving a static/driving suspension rating much closer to the value of the main spring. This then releives the locking up pressures on the hub when steering. Now if you fitted a full length rebound spring and it was under load at static rest or straight ahead, when driving all is fairly well, but then you go into a hard corner and the force on the outside suspension equalises the loading of the two springs together now being pushed in the same direction and this has a softening effect on that unit so some chassis stiffness is lost because first the rebound spring being much smaller is quickly overcome and so the total springs rating is provided by the main spring. This then is how a resolution moved to higher rate main springs. Let's stop here other than to say all these modifications will sort one aspect of the suspension you are trying to fix yet introduce another that you might not want.
Incidentally, not all Morgan trad's left the factory with the same rebound spring requirements, I'm not going to go searching at the moment but can tell you that my 2010 plus 4 has RB's which are under load against the main spring whereas others have little to no loading at static rest, fairly sure the Roadster is one! This is to suit the driving characteristics Morgan intended for that mark. So care needs to be taken when changes are being made especially if you want to improve what you have and not make it a detrimental move because someone told you to cut the springs down. The SSL aims to cover this as you are able to adjust main spring loading and therefore take advantage of the progressive rate springs. But again for me personally I haven't felt enough advancement over a properly serviced standard set up to warrant the cost. Again though, I feel mine is as good as it could be and the cars I have driven with the SSL, I had no knowledge of their set-up. I will say again that the two mod's that I really felt improved handling and ride quality on my car were Brake reaction bars and Rog's suspension assisters. When pushing things along a bit the BRB's really take some of the skittishness out of the front end and that's a driving thing and the rear assisters really soften and damp the ride throughout the cabin, that's a comfort thing.
Last edited by sewin; 09/09/26 12:55 PM.
