Much of this has been answered by others, thanks to them all ~ however:
1. MMC response: The first time the Morgan test drivers drove a car so fitted with the SUPLEX Refinement System (Initially referred to as a 'Comfort Pack' in the development phase) they were impressed enough to want to try it themselves. They are now working with SUPLEX on further developments.
2. Shimmy: It is of course not the SUPLEX RS kit that causes shimmy, though the loss of friction by no longer having a compressed rebound spring will further reduce the friction in the steering. It is well known that removing the friction steering damper/blades and fitting ball thrust races can result in shimmy, hence the need often in those cases for a hydraulic steering damper, like used on many modern sports cars.
3. Lack of bump travel: this is one of the reasons why the rising rate spring characteristic is so beneficial, one can still have a soft initial spring rate for ride comfort yet no crashing through on big bumps as the spring rate increases to prevent it, another Morgan suspension guru was a little mistaken previously on this point too.
4. Rebound spring. A very stiff rebound spring together with rising rate mains gives significantly increased roll stiffness with good ride. Hence the very stiff rebound spring that never goes coil bound.
5. Specific damper: Every change of spring rate, whether linear or nonlinear/rising rate needs a new damper setting up, as on ALL cars by all car companies. That is what SUPLEX did with Bilstein. Bilstein does not list a damper for Morgans as they supply their damper with the SUPLEX kit. It will not work well with other spring rates of course. High and low speed bump and rebound settings are quite unique in this Bilstein damper matched to this rising rate spring system, so other dampers from other reputable manufacturers will not work as well as the specified Bilsteins on this spring system. Hence matched springs and dampers.
6. Different weights: the system was set up for a mid weight car but has been extensively tested from 750kg up to 950 kg (unladen) with no significant change in ride. Engines from 1.6 IL4, to 3.9 V8 and 3.7 V6. The ride frequency, which is what one feels, changes by only 6% between a 850kg car and a 950 kg car, so very little noticeable difference. Also the rising rate in bump means that in roll the spring rate increases as the car starts to roll, so a heavier car settles at a higher spring rate in roll, that in this case is less than a car on stiff linear main springs.
7. Adjustable height: The threaded shrouds with spring seats are there to accommodate the range of weights of cars so that the hub's static position on the kingpin can be adjusted to just kiss the rebound spring as required.
8. The SUPLEX RS was developed by SUPLEX UK Ltd in the UK headed by Dan White, I worked as an engineering consultant and test driver during the development of the spring rate and damper settings. Something I have done of many cars, trucks and military vehicles since the 1970's for many companies.
Morgan dealers with decades of road and track experience have tried the system and recommend it, including pleasingly Librands who also market the double wishbone system so well built by Peter Mulberry.
I hope that this has helped those that have been confused or misslead, but maybe I have met 'Quicksilver' before? Best regards PJB.
That's very interesting. Thank you for taking the time to post. I don't think we have met before
