| Description | Date | Identifier | |
| List of customer complaints regarding suspension issues, specifically 'bumping on buffers', with suggested remedies. | 23th May 1930 | Box 16 \ 7 Scan265 | |
| List of vehicle suspension issues and proposed remedies for various owners and trials. | 23th May 1930 | Box 16 \ 7 Scan266 | |
| List of car cases with details on issues and remedies, particularly concerning rear springs, swaying and buffers. | 24th May 1930 | Box 16 \ 7 Scan267 | |
| Complaints and potential improvements for the Phantom II springing system. | 24th May 1930 | Box 16 \ 7 Scan268 | |
| The specifications for front and rear springs. | 26th May 1930 | Box 16 \ 7 Scan269 | |
| Confirming two points regarding vehicle springing, including stronger springs for Continental cars. | 26th May 1930 | Box 16 \ 7 Scan270 | |
| Querying the unsprung weights of the PII model compared to the PI model. | 28th May 1930 | Box 16 \ 7 Scan271 | |
| Suspension issues, specifically weaker front springs and rear spring buffer clearance. | 31th May 1930 | Box 16 \ 7 Scan272 | |
| Alteration to the Phantom II front springs to drill and groove the plates for lubrication. | 3rd Jun 1930 | Box 16 \ 7 Scan273 | |
| Error in wheel and tyre weights, comparing them with internal figures and noting the goal to reduce road spring weight. | 4th Jun 1930 | Box 16 \ 7 Scan274 | |
| Calculation of the unsprung weight for a Phantom II rear axle. | 11th Jun 1930 | Box 16 \ 7 Scan275 | |
| Query about issuing a standardization sheet for 40/50 HP rear axle springs to avoid increased costs from a supplier. | 11th Jun 1930 | Box 16 \ 7 Scan276 | |
| Experimental 40/50 HP rear axle springs and associated lubrication difficulties. | 11th Jun 1930 | Box 16 \ 7 Scan277 | |
| Standardisation and ordering of 40/50 HP rear axle springs with rolled eyes. | 7th Jun 1930 | Box 16 \ 7 Scan278 | |
| Supply difficulties with heavier axle springs and the proposed standardisation of the rear spring 'Rolled Eye'. | 30th Jun 1930 | Box 16 \ 7 Scan279 | |
| Comparison of American and English car springing, suspension performance, and road handling characteristics. | 2nd Jul 1930 | Box 16 \ 7 Scan280 | |
| Tyre hardness and a disagreement over drilling shock damper valves. | 1st Jul 1930 | Box 16 \ 7 Scan281 | |
| Cover letter for notes on how to tackle 'springing' complaints from a service point of view. | 4th Jul 1930 | Box 16 \ 7 Scan282 | |
| Notes and recommendations on car springing, including rear and front spring weights and damper settings. | 4th Jul 1930 | Box 16 \ 7 Scan283 | |
| Vehicle suspension tuning and the design of cushions and squabs to improve ride comfort. | 4th Jul 1930 | Box 16 \ 7 Scan284 | |
| Analysis of vehicle suspension issues related to springs and shock absorbers. | 3rd Sep 1930 | Box 16 \ 7 Scan285 | |
| Offer to improve the springing on a Phantom II vehicle. | 3rd Sep 1930 | Box 16 \ 7 Scan286 | |
| Springing modifications made to a Phantom II car, model 56-GN. | 19th Sep 1930 | Box 16 \ 7 Scan287 | |
| Continued memo regarding arrangements to obtain a car from its owner. | 19th Sep 1930 | Box 16 \ 7 Scan288 | |
| Internal order for a pair of special stiffer type road springs from Firth Ltd. | 22th Sep 1930 | Box 16 \ 7 Scan289 | |
| Modifying under-strength road springs for the Phantom II chassis by adding extra plates. | 23th Sep 1930 | Box 16 \ 7 Scan290 | |
| Requesting the assembly of springs and plates in the garage for examination. | 25th Sep 1930 | Box 16 \ 7 Scan291 | |
| Request for information on road springs for the PII model, including types, weights and stiffness ratings. | 26th Sep 1930 | Box 16 \ 7 Scan292 | |
| Wor. to Hs. requesting information on a 20/25 HP Chassis to reply to a Mr. Beaver. | 26th Sep 1930 | Box 16 \ 7 Scan293 | |
| Calculations and assumptions for developing road springs for the PII model. | 1st Oct 1930 | Box 16 \ 7 Scan294 | |
| Car spring selection, adjustment, and weight considerations. | 1st Oct 1930 | Box 16 \ 7 Scan295 | |
| Passenger load assumptions and providing tables of weights for various car types on PI and PII chassis. | 1st Oct 1930 | Box 16 \ 7 Scan296 | |
| Spring assignments for various car models based on weight distribution calculations and questioning underlying assumptions. | 3rd Oct 1930 | Box 16 \ 7 Scan297 | |
| Negative effects of new front springs on a car's ride and appearance. | 3rd Oct 1930 | Box 16 \ 7 Scan298 | |
| Suggested reply to Mr. Beaver regarding his dissatisfaction with the ride quality of the 25 HP car. | 3rd Oct 1930 | Box 16 \ 7 Scan299 | |
| Requesting the supply and alteration of various low-rating road springs to specific measurements. | 8th Oct 1930 | Box 16 \ 7 Scan300 | |
| Correspondence regarding a customer's dissatisfaction with a suspension alteration and an offer to rectify it. | 9th Oct 1930 | Box 16 \ 7 Scan301 | |
| Car's springing test and arranging for new front springs. | 10th Oct 1930 | Box 16 \ 7 Scan302 | |
| Road test of car 58-GN, focusing on front spring performance, handling and appearance. | 4th Oct 1930 | Box 16 \ 7 Scan303 | |
| Changing springs and fitting a new carburetter with an air silencer to car 58-GN, weighing performance against engine noise. | 13th Oct 1930 | Box 16 \ 7 Scan304 | |
| Changing the springs and fitting an air silencer on car 58-GN, with interest in upcoming performance test results. | 15th Oct 1930 | Box 16 \ 7 Scan305 | |
| Letter discussing rear spring specifications, buffer clearance, and vehicle weights. | 17th Oct 1930 | Box 16 \ 7 Scan306 | |
| Spring rates and buffer clearances related to spare wheel placement on Phantom models. | 17th Oct 1930 | Box 16 \ 7 Scan307 | |
| On the timeline for modified springs for car 58-GN and the results of its performance tests at Brooklands. | 18th Oct 1930 | Box 16 \ 7 Scan308 | |
| Modification details for Phantom II rear road springs, comparing specifications before and after fitting an extra 2nd plate. | 18th Oct 1930 | Box 16 \ 7 Scan309 | |
| Specification for front and rear spring clearances for a Phantom II chassis with special stiffer road springs. | 27th Oct 1930 | Box 16 \ 7 Scan310 | |
| Notes on springing troubles and the causes of weak rear springs on the Phantom II chassis. | 1st Nov 1930 | Box 16 \ 7 Scan311 | |
| Procedure to address car spring issues by fitting stronger springs and adjusting buffer clearances. | 1st Nov 1930 | Box 16 \ 7 Scan312 | |
| Customer complaints regarding uncomfortable springs on Phantom II cars and potential remedies. | 1st Nov 1930 | Box 16 \ 7 Scan313 | |
| Future suspension improvements and ongoing investigations into ride comfort. | 1st Nov 1930 | Box 16 \ 7 Scan314 | |
| Remedies for suspension complaints such as hard low-speed riding and spring squeaks. | 1st Nov 1930 | Box 16 \ 7 Scan315 | |
| On shock damper load alterations and spring lubrication options for 20 HP cars. | 1st Nov 1930 | Box 16 \ 7 Scan316 | |
| Springing investigations on car 58-GN and the 20/25 HP chassis. | 1st Nov 1930 | Box 16 \ 7 Scan317 | |
| The springing and shock damper alterations for car 58-GN to improve ride quality. | 11th Nov 1930 | Box 16 \ 7 Scan318 | |
| Suspension damping tests and modifications to improve the car's ride quality. | 11th Nov 1930 | Box 16 \ 7 Scan319 | |
| The effects of low rating springs and damping modifications on vehicle stability, handling, and buffer clearances. | 11th Nov 1930 | Box 16 \ 7 Scan320 | |
| Analysis of rear suspension components and a proposal for a new method of testing ride comfort. | 14th Nov 1930 | Box 16 \ 7 Scan321 | |
| Responding to telegrams from America regarding vehicle spring modifications and testing. | 14th Nov 1930 | Box 16 \ 7 Scan322 | |
| Proceeding with bumper tests for lower rating springs and asking for cost allowances. | 14th Nov 1930 | Box 16 \ 7 Scan323 | |
| Telex message regarding production specifications for left-hand drive chassis, including springs and battery supply. | 14th Nov 1920 | Box 16 \ 7 Scan324 | |
| Cable proposing that the American branch supply its own springs for left-handed Phantom II models. | 14th Nov 1930 | Box 16 \ 7 Scan325 | |
| Disadvantages of the American branch supplying their own road springs. | 15th Nov 1930 | Box 16 \ 7 Scan326 | |
| Proposed front and rear spring deflection settings for American requirements, fearing excessive rolling. | 15th Nov 1930 | Box 16 \ 7 Scan327 | |
| Test results for the Phantom II suspension, specifically rebound control and axle movement. | 18th Nov 1930 | Box 16 \ 7 Scan328 | |
| Preliminary tests to restrain the rear axle movement on a Phantom II suspension system. | 17th Nov 1930 | Box 16 \ 7 Scan329 | |
| Road tests for sling lengths and their effect on buffer clearance and axle movement. | 17th Nov 1930 | Box 16 \ 7 Scan330 | |
| Tests and opinions on flexible road springs for the Phantom II model. | 18th Nov 1930 | Box 16 \ 7 Scan331 | |
| Principles of car springing and weight distribution. | 19th Nov 1930 | Box 16 \ 7 Scan332 | |
| Ride comfort tests conducted on a Phantom 11 car using a water spilling method. | 26th Nov 1930 | Box 16 \ 7 Scan333 | |
| Analysis of vehicle pitching and ride comfort in relation to damping, weight distribution, and seating position. | 26th Nov 1930 | Box 16 \ 7 Scan334 | |
| Report analyzing vehicle riding comfort tests and proposing design improvements. | 26th Nov 1930 | Box 16 \ 7 Scan335 | |
| Graph showing the effect of shock damping on rear seat riding comfort during springing tests on Ticknall Hill. | 26th Nov 1930 | Box 16 \ 7 Scan336 | |
| Graph from springing tests on Ticknall Hill showing the effect of weight distribution on rear seat riding comfort. | 26th Nov 1930 | Box 16 \ 7 Scan337 | |
| Graph from springing tests at Ticknall Hill comparing riding comfort at different speeds based on rear seat position. | 26th Nov 1930 | Box 16 \ 7 Scan338 | |
| Car spring flexibility and a strategy for supplying spare spring leaves to America. | 26th Nov 1930 | Box 16 \ 7 Scan339 | |
| Adjustments to car springing and deflection to improve riding qualities. | 27th Nov 1930 | Box 16 \ 7 Scan340 | |
| Urgent request for a set of special road springs for a Phantom II car, detailing the specifications. | 1st Dec 1930 | Box 16 \ 7 Scan341 | |
| Order office memo requesting the purchase of road springs for a Phantom II from Messrs. Firths. | 18th Nov 1930 | Box 16 \ 7 Scan342 | |
| Order and design discussion for Phantom II road springs. | 29th Nov 1930 | Box 16 \ 7 Scan343 | |
| Letter discussing the development and issues related to the springing of the Phantom II. | 1st Dec 1930 | Box 16 \ 7 Scan344 | |
| Vehicle ride improvements through changes in springing, weight distribution, and shock absorbers. | 1st Dec 1930 | Box 16 \ 7 Scan345 | |
| Technical letter by F.H. Royce discussing issues and improvements for shock dampers. | 23th Dec 1930 | Box 16 \ 7 Scan346 | |
| Dispatch and testing of new low rating road springs. | 23th Dec 1930 | Box 16 \ 7 Scan347 | |
| List of road springs ordered in 1930 for the Phantom II and 20 HP models. | 13th Dec 1930 | Box 16 \ 7 Scan348 | |
| Inquiring about the standardisation of using Rolled Eyes on Springs to reduce costs. | 10th Jan 1931 | Box 17 \ 1 Scan001 | |
| Scheme for a rolled eye, which is now awaiting costs. | 12th Jan 1931 | Box 17 \ 1 Scan002 | |
| Order for 25 sets of springs for the N.2 series, and the standardisation of rear springs with rolled eyes. | 15th Jan 1931 | Box 17 \ 1 Scan003 | |
| Internal order memo for front and rear 40/50 model road springs with specifications. | 23th Jan 1931 | Box 17 \ 1 Scan004 | |
| Querying the type of springing for 40/50 HP chassis for the home market compared to the American market. | 4th Feb 1931 | Box 17 \ 1 Scan005 | |
| Tests of lower rating springs for the Phantom II, outlining the results and subsequent issues. | 7th Mar 1931 | Box 17 \ 1 Scan006 | |
| Road tests and modifications to improve car springing, ride comfort and weight distribution. | 7th Mar 1931 | Box 17 \ 1 Scan007 | |
| Suspension and frame distortion tests on various car models. | 4th Dec 1930 | Box 17 \ 1 Scan008 | |
| Standardisation of a rolled eye on a Phantom 11 rear road spring to reduce cost. | 4th Dec 1930 | Box 17 \ 1 Scan009 | |
| Standardisation form for a new chassis part detailing the test chassis and associated costs. | 6th Jun 1931 | Box 17 \ 1 Scan010 | |
| Particulars of cars fitted with low rating road springs, excluding model 20-EX. | 7th Mar 1931 | Box 17 \ 1 Scan011 | |
| Specification sheet for springing, detailing front and rear springs, damper loads, car weight, and buffer clearances. | 7th Mar 1931 | Box 17 \ 1 Scan012 | |
| Specifications for springing, including spring loads, camber, damper settings, car weight, and buffer clearances. | 7th Mar 1931 | Box 17 \ 1 Scan013 | |
| Specification sheet for vehicle springs, dampers, weight, and clearances. | 7th Mar 1931 | Box 17 \ 1 Scan014 | |
| Specification sheet for car springing, damper loads, car weight, and buffer clearances. | 7th Mar 1931 | Box 17 \ 1 Scan015 | |
| Springing specifications for vehicle 18-EX as it left Derby, detailing front and rear springs and damper loads. | 7th Mar 1931 | Box 17 \ 1 Scan016 | |
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