Modern, Traditional and Classic & race car suspensions.


Updated May 19th  2021

Armstrong lever arm adjusable valve

7. MGF, replace the 'extinct' Hydragas suspension units for coil spring canisters and dampers. Designed & Developed by SSL. This can be considered to be a 'Distress Purchase' as otherwise the car will be off the road with a failed Hydragas suspension unit. This kit gets the car back on the road with a reliable system.


The system has TuV approval for fitment in those European countries that need TuV approval.


Available from 'XPart'  or Rimmers or Moss etc

mgf box2 copy

1. Adjustable valves for Armstrong lever arm dampers.

These are a straight exchange for the standard valves. SSL will flush your old units, fill, bleed and fit the new adjustable valves or provide just the valves. Adjustment is with a 8mm hex.

Will fit a wide range of cars including MGA, MGB, MG Midget, Morgans, A35. Just ask SSL for advice.

5. Leaf spring design and manufacture: SSL are developing leaf spring design software, but tend to rely on experience and advice from the leaf spring manufacturer in Sheffield we work with.


SSL has its own leaf spring rate test rigs for semi and quarter elliptic springs  where the spring can be loaded in small steps and the force measured. The load is then relaxed and measurements taken again and average taken to negate the stiction hysterisis effect. Graphs of the rate showing the progression are provided.


SSL have worked on historic sports cars' leaf springs to achieve the required rate and progression.


SSL also design asymmetric leaf springs that better resist windup under hard acceleration and gear changes.







Far Right MGB Race springs at 130 lbf/inch and lowered for race regulations.

MGB FIA Leaf spring test

3. Coil spring design and manufacture: Spring design calculations can be done to suit special applications maybe where space is limited. Can build in progression and maximise fatique life.


SSL work closely with a coil spring manufacturer in Sheffield who can make in small and large volumes. Specials can be design and made at short notice.


SSL can use its software to calculate quite accurately the rate (stiffness) of a coil spring from measurements of wire thickness, total number of coils end to end, and spring id or od.


SSL has design software to design a progressive spring that starts soft for good ride and stiffens in bump for good handling and load carrying capacity.  


Just ask.

4. SPAX dampers for special applications.

SSL have a good working relationship with SPAX. We will help specify SPAX dampers for special projects. SSL & SPAX will need at least: fully open length, fully closed length, bolt sizes, wheel/spring rate, corner weight, bump stop lengths. Contact SSL for details.

SSL cream discs
065_019 from Holdens

Suspension springs and dampers


1. Adjustable valves for Armstrong lever arm dampers.

2. Friction damper discs for Andre Hartford type.

3. Coil springs.

4. Special SPAX dampers

5. Leaf springs.

6. Special springs.

7. MGF replacement steel springs for Hydragas.

2. Discs for friction dampers, Andre Hartford type.

No stiction, thus now allows the suspension to absorb road surface degradations and flow over undulations, significant improvement in ride and handling.


SSL will supply discs to pattern or dimensions.

3 springs

6. Special springs, coils or leaves. Whether for oil releif valves, securing wheel spinners, holding on exhausts etc ask us as we can design using the latest spring software and get manufactured.


Just ask.

P2273012 - Copy
hub spring
mgb rear springs
SSL adj valve white - jpg
magic test

The Bugatti Type35A now rides well allowing the leaf springs to work, but then the car settles quickly after a bump, corner or braking as you would expect it to do with hydraulic dampers.

Also incorporated is an adjuster to actually set the friction level of the damper, as std there is a coil spring under preload that expands the shoe that needs to be replaced to adjust the damping.

Now fitted successfully to: Lagonda Rapide, Bentley 4.5, Riley Falcon, Riley MPH, AustinSeven, Morgan 4/4 Series1, Brough motorcycles, Morgan three wheeler 1930s, RollsRoyce Phantom engine vibration damper. Cut to size with technical support. Stiffer coil springs provided on those dampers without the 'star' finger springs.

A7 SSL discs cream

Open the YouTube links below in a new tab.

Original Bugatti Type35 friction damper correctly greased bronze ring and adjusted, being articulated by hand.

Modified Bugatti Type35 friction damper with SSL synthetic friction material set at the same dynamic load and being articulated by hand.

AustinSeven front double friction damper.

Right lever as standard very jerky.

Left lever with SSL synthetic material set at the same dynamic load, so smooth!

The Austin Seven later used this twin damper arrangement. The lack of stiction allows the car to settle after a corner and run straight and true. The car also settles very quickly after a bump as it would be expected to do with telescopic dampers.