Sorry, guys missed the questions aimed at me. This is the text AeroRacing are putting out ref the SUPLEX upgrade for the M3W:
*************** Morgan Three Wheeler ~ AeroRacing/SUPLEX Suspension Upgrade
SUPLEX UK Ltd, the major suspension supplier to Morgan Motor Company, has developed a new and sophisticated front and rear suspension system to give handling worthy of a high performance lightweight sports car yet give good ride on variable sealed tarmac type surfaces. This is available from your Morgan dealers through Morgan ‘AeroRacing’.
The front suspension is designed to give high resistance to roll to encourage maintenance of high cruising speeds through fast corners with good steering control and precision, yet is soft enough over road surface roughness to give a comfortable ride but is still able to stiffen up over bigger bumps to prevent unpleasant thumps. The damping is adjustable to enable the car to be set up for different weights of occupants and luggage. NB This front suspension system will work very well with the original steering configuration as it limits unpleasant ‘bump steer’ and is of course also compatible with the later Morgan ‘Comfort Pack’ steering configuration.
The rear suspension is designed to provide good ride for just the driver or ‘two up’ with significant luggage by the springs stiffening up in bump that work in conjunction with adjustable damping.
How is this done? The unique front dampers incorporate an internal rebound spring that significantly stiffens the suspension in rebound/droop, so in a fast corner the inside front corner will not lift on the suspension and only the outer wheel suspension compresses. Thus the instantaneous roll centre moves from the vehicle centre line to the contact patch of the inner wheel and thus not only very significantly increases roll resistance but the roll centre stays fixed in that location during the corner facilitating accurate steering precision. [This effect mirrors the high roll resistance effect achieved with the highly successful SUPLEX RS front suspension system on the ‘Traditional’ four wheelers.] The front suspension units also incorporate an elastomeric ‘spring assist’ on the damper rod that is far more sophisticated than a simple bump stop, this significantly stiffens the suspension in bump to allow good ride over rough surfaces yet is able to absorb the bigger bumps before full bump impacts occur. Although there is a threaded spring seat, this is only there to ensure the correct ride height dependent on the weight carried. The dampers are highly gas pressurised ‘mono tubes’ to maintain the damping levels when used hard as the fluid will not foam and the heat generated is quickly dissipated. An easily accessible knob will adjust the damping in a fixed bump:rebound ratio by adjusting the internal valving; this is to ensure that the excellent ride control can be maintained for whatever weight is carried.
The rear dampers are also highly gas pressurised ‘mono tubes’ with easily adjustable damping with a fixed bump:rebound ratio to give the same ride and handling benefits as the front dampers. The spring however is a nonuniformly wound progressive/rising rate spring that gives a soft ride over normal road surfaces yet again will stiffen over bigger bumps or when significant luggage is carried. There are also rebound springs in the rear units to control the rear wheel over big bumps, bearing in mind all rear load is on one wheel so is not split between two wheels. The rebound spring limits the lift of the rear after a bump to prevent loss of steering directional control that would otherwise occur with a momentary reduction is steering castor angle. There are also spring seat height adjusters so that the rear ride height can be set to accommodate a wide range of weights of occupants and luggage.
Summary – this is a very sophisticated total vehicle suspension system able to provide excellent handling for such a light high performance three wheeler yet achieve high levels of comfort for longer journeys two up with luggage. *****************
The ride height and dampers are set from SUPLEX to suit normal usage. Regards PJB.
