Front Suspension : SSL (Was SUPLEX) Refinement System

NB As from January 2017 SSL (Suspension Supplies Ltd) have taken over supply of the RS front suspension system from SUPLEX. The same design, same manufacturers, same engineers just different branding.

Front Suspension Ride and Handling Refinement!

     As many of you know, I have been experimenting for a few years with different springs and dampers on the front of my 4/4 to improve the ride and handling. In the last two years, I have also been supporting Mr Dan White the ‘Suspension Guru’ and MD of ‘SUPLEX UK Ltd’, as a test driver and engineering consultant. SUPLEX UK Ltd are half of the German based SUPLEX GmbH who are one of the leading aftermarket automotive suspension spring (coil and leaf) suppliers in Europe. They also supply Morgan Motor Company with their front suspension coil springs and resell some dampers.
    With components from SUPLEX, very significant improvements in ride and handling have been achieved compared with the base models. 

    The older traditional Morgans have a compressed rebound spring at static ride height that significantly increases the initial spring rate resulting in a harsh ride and the typical sideways skittering when pushing hard through a bumpy corner. This set up results in a spring rate that gets softer after about 3/4 inch as the rebound spring goes free of the hub, this can also upset the stability in a fast corner as the outer front wheel dips. 
I quote from "The ride? Those concerned with modern suspension systems would no doubt cry from anguish or mirth, if driven fast over rough roads in the Plus-8. On really bad going the car seems to have no springs. In less bad roads it just jumps around and rattles. On main roads it floats along nicely. Trying hard on Welsh mountain passes the Morgan felt less safe than the Gilbern and I would think that a competition driver would lose time when the back-end bounced upwards and sideways and by the front-end suddenly going softish.". So he spotted the effect at the front then, BUT did not know why - also more work on the rear suspension required then too - next project?!
    Traditional Front Suspension Spring Rate.

     Some current Morgans now run an improved system with a linear main spring and an uncompressed rebound spring (eg ‘4/4’ and ‘Roadster’) to give better ride but it is still a compromise between ride and handling. Also the bump travel is still limited by the very stiff rubber bump stop sleeve up inside the shroud/dust-cover that jars the occupants over big bumps. Various dampers are fitted to the different models, but are often a compromise between ride and handling.
    Current Front Suspension Spring Rate.

     After thousands of miles of testing on my car and that run by the MD of SUPLEX UK, 'we' have developed a rising rate spring system for the front to give greatly improved and refined ride and handling, indeed a Front Suspension 'Refinement System'!

    This new highly developed 'Refinement System' provides a soft initial bump rate to absorb typical road surface roughness but soon stiffens up to minimise bump stop impacts but also provides significantly increased roll stiffness and thus an improvement in road holding and handling. The system also utilises some of the useful extra potential bump travel currently taken up with the stiff rubber bump stop up inside the shroud/dust-cover. The ability of the tyre to now stay in better contact with the ground over rough road surfaces also improves road holding. The system has been completed with a new tuned unique Bilstein gas pressuried monotube damper with internal elastomeric bump stop that was developed in the UK at the Bilstein Technical Centre.
    SSL (wasSUPLEX) Front Suspension 'Refinement System'.
    The Front Suspension 'Refinement System' can easily be set up for different weight and ride heights of cars with the new threaded shroud/dustcover with an adjustable spring seat/locking ring, and it can also be used with the traditional damper blade/ friction thrust plate or with the current sealed ball thrust race.
    The Front Suspension 'Refinement System' will fit all 'Classic' Morgans from the 1950's Plus4 to the current models, using the 1 inch king pin.
     A full kit including main spring, 'rate riser' spring, rebound spring, spacer, threaded adjustable shroud with spring seat, thrust race and dampers will be supplied through selected Morgan dealers & specialists for them to fit or for owner installation. Full installation instructions and 'C' spanners for the height adjuster are included.
    Anybody who has already removed and replaced king pins will be able to complete the conversion themselves – with care. It is interesting to note that the integral threaded height adjuster shroud serves as the spring compressor for the new springs, so no need for clever devices to precompress the main springs.
    The Front Suspension 'Refinement System' will be available in APRIL 2013 from Morgan dealers and specialists and maybe other sources. If you do not have a favourite dealer/specialist who helps you keep your Morgan rolling, then call UK 01909 770660 in April 2013 onwards to find your nearest supplier.
Photos and independent road tests to follow as the system gets released to the press - stay tuned!
UPDATE 29/3/13
The following cars have been fitted so far with the system with consistent results of much improved ride, less roll, no 'nodding dog'/'nose bobbing':
1986 4/4 2.0 Zetec
2003 4/4 1.8 Zetec
1954 Plus4 TR3
1973 Plus8 3.9 weighing 950 kg.
Thus SSL (was SUPLEX) are confident that the system is suitable for all Morgans since the Plus4 in 1954, right up to and including the heaviest current model the Roadster at 950 kg (dry).
The following English Dealers/Specialists will supply and fit, they have all tried the test car and love it, ask them:
1. Mike and Ben Duncan ~ Hartlebury, Kidderminster, Worcestershire.
2. Melvyn Rutter ~ Little Hallingbury, Bishops Stortford, Hertfordshire
3. Williams Morgan - Horton, Chipping Sodbury, Bristol.
4. Tudor Motors ~ Market Drayton, Shropshire.
See the list of SUPPLIERS 91 Suppliers on this site for the contact details for the above.
UPDATE 1/4/13
From May 2013 'Classic and Sports Car':-
UPDATE 11/4/13
The following cars have been fitted so far with the system with consistent results of much improved ride, less roll, no 'nodding dog'/'nose bobbing':
1986 4/4 2.0 Zetec
2003 4/4 1.8 Zetec
1954 Plus4 TR3
1973 Plus8 3.9 weighing 950 kg.
2005 3.0  V6 Roadster
 With a pair of tuned:-
The Bilstein monotube dampers (development item shown above!) have been tuned to match the new suspension system characteristics and the weight of the cars. The damper characteristic also takes into account the inevitable friction of the hub on the kingpin during bump and rebound.
Thus in bump the rate at high speed (of damper closing) is kept low to provide good ride, yet low speed bump is sufficient to give good turn-in for responsive steering and control over a series of undulations or lane change.
Then rebound damping has also been kept low enough to avoid 'jacking down' that can occur when the quite soft main spring can not quite return the hub to normal ride height quick enough before the next bump due to too high rebound damping and due to the friction in the hub on the king pin. The matched rising rate rebound spring also absorbs some of the energy of the rebounding hub if the rebound damping does no slow it enough.
UPDATE 27/4/13
The following cars have been fitted so far with the system with consistent results of much improved ride, less roll, no 'nodding dog'/'nose bobbing':
1986 4/4 2.0 Zetec
2003 4/4 1.8 Zetec
1954 Plus4 TR3
1973 Plus8 3.9
2005 3.0 V6 Roadster
2011 +4SS
2XXX 3.7 V6 Roadster
2007 +4 4seater, 2 litre Duratec.
So at this stage the system has been fitted to a full range of:
Years from 1954 to current.
Weights from 750 kg to 950 kg (dry)
Power outputs/performance from 100 bhp to around 280 bhp.
All have been satisfied with the improved ride and handling.
The following dealers have or are just about to supply/fit the system and have all driven cars so fitted:
William Morgans, Melvyn Rutter, Mike & Ben Duncan, Beamish Morgans, New Elms, Tudor Vernon,
Also driven the test car, not sure if supplied yet, Ledgerwood Morgans.
UPDATE 29/12/16
SSL Instructions as PDF files attached, see below:
UPDATE 29/12/1
Latest news; over 20 UK Morgan dealers and specialists have now fitted these kits to the full range of Morgans with overwhelming success.
When there is feedback from owners that is great, but when there is enthusiastic feedback from owners as well as Morgan dealers who have raced, owned and serviced our cars for decades that is very reassuring. Great positive feedback has been received from such as 'Mike and Ben Duncan', Rob Wells [Librands], John MacDonald [Beamish], Terry Foxen [GEE], Melvyn Rutter, Kevin Vernon [Tudor Vernon] and the Williams Autombile team etc.
Recently an owner who was dedicated to his standard suspension system had to admit that the SUPLEX suspension just seemed able to float over road surface imperfections, so that the tyres remained in contact with the road surface (Always a good idea) but that the car was riding above them still in control. Another owner said that the ride over typical broken road surface was 'uncanny' as the suspension absorbed so much more than the standard set up of his +8.

Recently an owner who has driven and competed in Morgans for decades was enthusiastic enough to fit a kit before his 3,000 mile tour of European mountain passes, this is what he said:
Damping ~ Some owners and indeed one or two dealers have asked why SUPLEX have specified a Bilstein damper rather than off the shelf adjustables that we all know. Well the SUPLEX suspension characteristic is quite unique and of course even a well serviced kingpin and hub can still have some inherent friction. So a lot of time and alternative  settings were tried to optimise a damper for this spring characteristic and Morgans.
    Aftermarket twin tube adjustable dampers indeed have their place, but they have limitations; their main deficiency is that to make them adjustable the damper adjustment is controlled through a simple bleed hole and a tapered screw and this can not give the optimum characteristic. A monotube nonadjustable damper such as a Bilstein controls all the flow in bump and rebound through very sophisticated shims and passages to give just the right characteristic. So firm damping for control in 'lane change', turn into a corner, braking etc but then good compliance over broken surfaces to give both good ride and handling. Bilsteins also separate the gas from the oil so that an oil/gas foam is never produced that would reduce damping in hard use, like many adjustables exhibit. Also consider that each year Lotus buy 30,000 Bilstein dampers for their sports cars of the same technology but again tuned for their suspension and cars.
    SUPLEX and Bilstein have also set the characteristics so that they work well for the lighter cars (older 4/4) as well as the heavier cars +8 and the latest 3.7 Roadster. As expected there are no observations that the rates are too stiff on the light cars nor too soft for the heavier cars. Even though there is obvious weight variation between the models over the years this is not that significant for what the springs and dampers have to achieve.
So if you are interested then ask a dealer or try a demo car or ask one of the experts.
Morgan Dealers and specialists in UK should contact SSL for supply.

Road tests of a 1986 4/4 (2.0 16v) and a 1973 3.9 +8, by a SUPLEX customer as printed in MSCC Miscellany.

Also attached is the 'Quick Setup' instructions for those who are familiar with the dismantling and reassembly but covers the way to test and set the adjustment and tighten the damper nuts.

Peter J. Ballard. CEng. MIMechE.  (Just the nut behind the wheel).

Peter Ballard,
Dec 29, 2016, 4:15 AM
Peter Ballard,
Dec 29, 2016, 4:14 AM