| Description | Date | Identifier | |
| Road test report on vehicle I4-EX from France, detailing performance, issues, and adjustments. | 25th Feb 1928 | Box 72 \ 2 scan0267 | |
| Test report on car 14-E.X. detailing engine performance, a steering noise, and body noises. | 11th Mar 1928 | Box 72 \ 2 scan0268 | |
| Vehicle 14.E.X. performance after 6,129 miles, detailing engine, oil, and electrical status. | 25th Mar 1928 | Box 72 \ 2 scan0269 | |
| Vehicle performance report detailing misfiring issues and observations on the steering, brakes, rear axle, springing, and bodywork. | 25th Mar 1928 | Box 72 \ 2 scan0270 | |
| Car rattles and the effect of tyre pressure on ride comfort. | 7th Apr 1928 | Box 72 \ 2 scan0271 | |
| Progress report from Dodd to Mr. Hives concerning car 14.E.X., detailing an electrical issue and a query about front springs. | 7th Apr 1928 | Box 72 \ 2 scan0272 | |
| From F. Dodd about daily outings of 'R' in vehicle 18EX. | 12th Sep 1930 | Box 72 \ 2 scan0273 | |
| Cover sheet for correspondence relating to cars for R's (Royce's) use. | 8th Mar 1928 | Box 72 \ 2 scan0274 | |
| Chassis specification memo discussing the production timeline for the 'H' engine and 'SS' chassis, including testing and considerations for a USA version. | 8th Mar 1928 | Box 72 \ 2 scan0275 | |
| Cost, logistics, and justification for testing a Sports No.1 car in the USA. | 12th Jan 1928 | Box 72 \ 2 scan0276 | |
| Re-testing of the Sports No.1 car in the United States during winter conditions. | 5th Jan 1928 | Box 72 \ 2 scan0277 | |
| Proposal and logistics of sending a 'Sports No.1' car to the USA for testing. | 16th Jan 1928 | Box 72 \ 2 scan0278 | |
| The testing of a Sports No.1 car in the USA and the unavailability of a chassis. | 17th Jan 1928 | Box 72 \ 2 scan0279 | |
| 'VERY SECRET' cover note from BJ to Hs, enclosing a copy of a letter sent to Mr. Fullerton. | 17th Jan 1928 | Box 72 \ 2 scan0280 | |
| 'Very Secret' letter discussing the challenges of coordinating chassis production and modifications between Derby and America. | 17th Jan 1928 | Box 72 \ 2 scan0281 | |
| 'Very Secret' letter discussing the development and production strategy for a new chassis, camouflaged as the 'Super Sports Model', for the American market. | 17th Jan 1928 | Box 72 \ 2 scan0282 | |
| Letter discussing a scheme to reduce costs by increasing chassis production for the American market. | 17th Jan 1928 | Box 72 \ 2 scan0283 | |
| Springing chart for 40/50 HP cars to determine spring poundage based on total vehicle weight. | 9th Jun 1922 | Box 72 \ 3 scan0001 | |
| Blueprints, poundages, and quantities for front and rear springs to be ordered. | 23th Jul 1923 | Box 72 \ 3 scan0002 | |
| Directive to increase the poundage of front springs by 100 lbs on all chassis. | 12th Oct 1923 | Box 72 \ 3 scan0003 | |
| Steering and front spring breakages and proposed design changes to resolve them. | 16th Jan 1924 | Box 72 \ 3 scan0004 | |
| Potential causes and solutions for front road spring breakages. | 16th Jan 1924 | Box 72 \ 3 scan0005 | |
| Continued page of a document asking about the relative merits of balloon tyres and larger wheels. | 27th Jan 1924 | Box 72 \ 3 scan0006 | |
| Advantages of a slow speed ratchet driven servo for vehicle braking systems. | 27th Jan 1924 | Box 72 \ 3 scan0007 | |
| Page two of a typed memo from F.H. Royce regarding modifications to the 40/50 model's springs, buffers, and servo brakes. | 19th Feb 1924 | Box 72 \ 3 scan0008 | |
| Outlining modifications and an investigation concerning front springs on various EAC models. | 19th Feb 1924 | Box 72 \ 3 scan0009 | |
| Secret memo from D.A. explaining a delay in dispatching design prints due to reprioritizing work from project EAC.4 to the servo on EAC.3. | 19th Feb 1924 | Box 72 \ 3 scan0010 | |
| Proposed 25% increase in front spring stiffness. | 6th Mar 1924 | Box 72 \ 3 scan0011 | |
| Frame failure during a bumping test, caused by a new bracket controlling the front spring. | 11th Mar 1924 | Box 72 \ 3 scan0012 | |
| Technical memorandum discussing a weak point in a frame after bumping tests and proposing a design for a stiffener. | 13th Mar 1924 | Box 72 \ 3 scan0013 | |
| Suggested reinforcement for the frame at the front spring anchorage to prevent buckling failure. | 18th Mar 1924 | Box 72 \ 3 scan0014 | |
| Secret memo discussing steering stress issues when hitting an obstruction and potential improvements. | 16th Apr 1924 | Box 72 \ 3 scan0015 | |
| From GWH to Mr. Hives regarding unsatisfactory gaiters fitted to new type front springs. | 24th Apr 1924 | Box 72 \ 3 scan0016 | |
| Secret memo recommending a special note be added to drawings for the bracket for the rear end of the front springs. | 12th May 1924 | Box 72 \ 3 scan0017 | |
| Spring deflection and pivot inclination during front wheel braking. | 20th May 1924 | Box 72 \ 3 scan0018 | |
| On the decision to braze rather than solder front spring brackets for four-wheel brakes due to cracking found during testing. | 3rd Jul 1924 | Box 72 \ 3 scan0019 | |
| The decision to dip-braze the anchor bracket for the rear end of the front spring. | 4th Jul 1924 | Box 72 \ 3 scan0020 | |
| Post Office telegram confirming springs have been fitted to a car, which is awaiting testing. | 9th Jul 1924 | Box 72 \ 3 scan0021 | |
| Secret memorandum discussing criticism of stiff rear springs and proposing improvements for car suspension. | 12th Jul 1924 | Box 72 \ 3 scan0022 | |
| Vehicle performance, noting issues with the rear suspension and suggestions for damping. | 17th Jul 1924 | Box 72 \ 3 scan0023 | |
| Arrangements for testing two different sets of front springs on cars 98-NK and 107-MG. | 17th Jul 1924 | Box 72 \ 3 scan0024 | |
| The second page of a typed document discussing a convincing test for Sales Officials. | 17th Jul 1924 | Box 72 \ 3 scan0025 | |
| Telephone message discussing car suspension issues, specifically internal friction in different types of springs. | 17th Jul 1924 | Box 72 \ 3 scan0026 | |
| Springing tests conducted on car EAC.111. | 17th Jul 1924 | Box 72 \ 3 scan0027 | |
| Tests on modified front springs and braking for car model 107-MG. | 17th Jul 1924 | Box 72 \ 3 scan0028 | |
| Comparing the internal friction and damping of road springs from manufacturers Firths and Woodheads. | 18th Jul 1924 | Box 72 \ 3 scan0029 | |
| Confirmation of a telegram discussing spring stiffness and braking performance. | 18th Jul 1924 | Box 72 \ 3 scan0030 | |
| Relaying messages from 'R' (Royce) regarding issues with car spring friction and stiffness. | 18th Jul 1924 | Box 72 \ 3 scan0031 | |
| Telegram from Basil Johnson regarding a vehicle trial and a price reduction. | 18th Apr 1924 | Box 72 \ 3 scan0032 | |
| Telegram discussing a complaint regarding increased stiffness and internal friction in vehicle springs. | 1st Jan 1937 | Box 72 \ 3 scan0033 | |
| Telegram discussing a stiffness reduction and its effect on braking proportions. | 1st Jan 1937 | Box 72 \ 3 scan0034 | |
| Secret memorandum discussing issues and potential improvements for the car's springing and suspension system. | 19th Jul 1924 | Box 72 \ 3 scan0035 | |
| Alterations to the front springing, braking servo, and axle design for specific car models. | 24th Jul 1924 | Box 72 \ 3 scan0036 | |
| The supply, fitting, and testing of 12 1/2% weaker front springs on various cars. | 25th Jul 1924 | Box 72 \ 3 scan0037 | |
| Delivering a car for holidays and returning another test car for examination. | 25th Jul 1924 | Box 72 \ 3 scan0038 | |
| Testing of two cars with 12.5% weaker front springs for different body types. | 28th Jul 1924 | Box 72 \ 3 scan0039 | |
| Confirming a satisfactory arrangement for 12 1/2% weaker front springs. | 30th Jul 1924 | Box 72 \ 3 scan0040 | |
| On the comparative road testing of a Derby cabriolet and a London demonstrating car, focusing on ride harshness and suspension adjustments. | 1st Aug 1924 | Box 72 \ 3 scan0041 | |
| Vibration issues by fitting stronger front brake springs and a heavy axle to a demonstration landaulet. | 7th Aug 1924 | Box 72 \ 3 scan0042 | |
| Typed memo detailing a road test comparison between a cabriolet with front-wheel brakes and a standard landaulet. | 1st Aug 1924 | Box 72 \ 3 scan0043 | |
| Phone message confirmation regarding car suspension spring stiffness and ride comfort. | 7th Aug 1924 | Box 72 \ 3 scan0044 | |
| Works order for the despatch of two front road springs via passenger train to St. Pancras station. | 8th Aug 1924 | Box 72 \ 3 scan0045 | |
| Instructing the Stores to dispatch two front road springs via passenger train to a mechanic at St. Pancras Station. | 1st Aug 1924 | Box 72 \ 3 scan0046 | |
| Swapping the axle and springs between a Cabriolet and a London Trials Landaulet to accommodate front-wheel brakes. | 1st Aug 1924 | Box 72 \ 3 scan0047 | |
| The urgent testing of a cabriolet car's front springs and brakes, comparing performance against other models. | 28th Aug 1924 | Box 72 \ 3 scan0048 | |
| Telegram cancelling a previous memo and giving new instructions for a front axle trial. | 8th Aug 1924 | Box 72 \ 3 scan0049 | |
| Telegram discussing the harshness of new pack springs and requesting mileage information for car 98 NK. | 9th Aug 1924 | Box 72 \ 3 scan0050 | |
| Copy of a telegram discussing uncomfortable springing on open cars and proposed tests. | 9th Aug 1924 | Box 72 \ 3 scan0051 | |
| Telegram regarding car suspension and brake testing, including a suggestion from Mr. Royce. | 9th Aug 1924 | Box 72 \ 3 scan0052 | |
| Confirmation of a telegram regarding testing of uncomfortably harsh springing and brakes on an open car. | 11th Aug 1924 | Box 72 \ 3 scan0053 | |
| Trial of a demonstration landaulet and issues with its front wheel spring fitment. | 11th Aug 1924 | Box 72 \ 3 scan0054 | |
| Testing and implementation of stronger front springs for four-wheel brake cars. | 11th Aug 1924 | Box 72 \ 3 scan0055 | |
| The results of tests on front wheel brakes and spring configurations on a demonstration landaulet. | 11th Aug 1924 | Box 72 \ 3 scan0056 | |
| Results of tests on front wheel brakes and suspension for a demonstration landaulet. | 11th Aug 1924 | Box 72 \ 3 scan0057 | |
| The results of tests on front wheel brakes and spring configurations on various cars. | 11th Aug 1924 | Box 72 \ 3 scan0058 | |
| Testing of car springs and front brakes, including a wire detailing issues with harsh stopping. | 11th Aug 1924 | Box 72 \ 3 scan0059 | |
| Secret internal memorandum discussing the performance of road springs on cars with four-wheel brakes. | 1st Aug 1924 | Box 72 \ 3 scan0060 | |
| Tests on front wheel brake parts and springs for the 4-wheel brake cars. | 11th Jun 1924 | Box 72 \ 3 scan0061 | |
| Telegram reporting on the performance of a demonstration landaulet with a modified heavy front axle and stronger springs. | 11th Jun 1924 | Box 72 \ 3 scan0062 | |
| Telegram received by telephone regarding modifications to a bonnet and a whistle. | 23th May 1923 | Box 72 \ 3 scan0063 | |
| Telegram received by telephone concerning the fitting of unconnected front wheel brakes to a demonstration car. | 23th May 1923 | Box 72 \ 3 scan0064 | |
| Telegram concerning the fitting of a front brake axle and springs to car 107-MG. | 12th Aug 1924 | Box 72 \ 3 scan0065 | |
| Fixing of a front brake axle and springs on an open trials car. | 12th Aug 1924 | Box 72 \ 3 scan0066 | |
| Attaching a copy of a reply to a request. | 12th Aug 1924 | Box 72 \ 3 scan0067 | |
| Telegram from Basil Johnson to Hives regarding a car's performance and suggested modifications. | 12th Aug 1924 | Box 72 \ 3 scan0068 | |
| Front wheel brake tests, spring ordering, and results from a spring endurance test. | 12th Aug 1924 | Box 72 \ 3 scan0069 | |
| Performance and testing of road springs on cars fitted with four-wheel brakes. | 12th Aug 1924 | Box 72 \ 3 scan0070 | |
| Testing of front brakes, springs, and axles on a demonstration landaulet and chassis 107-MG. | 12th Aug 1924 | Box 72 \ 3 scan0071 | |
| Testing of front wheel brake springs on a trials landaulet. | 12th Aug 1924 | Box 72 \ 3 scan0072 | |
| Production status and testing of front springs for four-wheel brake systems. | 12th Aug 1924 | Box 72 \ 3 scan0073 | |
| Adoption of a 12.5% stronger spring, its performance compared to the standard 40/50 model, and the impact on vehicle delivery. | 12th Aug 1924 | Box 72 \ 3 scan0074 | |
| Short internal memo from B.J. to Hs chasing a reply regarding R.R. Springing. | 13th Aug 1924 | Box 72 \ 3 scan0075 | |
| Secret memo questioning an unauthorized change to the stiffness and friction of rear springs. | 22th Jul 1924 | Box 72 \ 3 scan0076 | |
| The fitting and testing of new brakes and springs on an open demonstration car. | 14th Aug 1924 | Box 72 \ 3 scan0077 | |
| Stiffness and examination of rear springs on the EAC.11 speed model car. | 14th Aug 1924 | Box 72 \ 3 scan0078 | |
| From CJ to R. regarding the trial of a Landaulet fitted with a heavy axle and specific springs, agreeing to proceed with manufacture. | 14th Aug 1924 | Box 72 \ 3 scan0079 | |
| Stiffness of front springs in relation to body weight and 4-wheel brakes. | 14th Aug 1924 | Box 72 \ 3 scan0080 | |
| Secret memo regarding a correction to the stiffness percentage of front springs for 4-wheel brakes. | 15th Aug 1924 | Box 72 \ 3 scan0081 | |
| Serious accident in France with a 35-PK open touring car during tests on stiffer front springs. | 18th Aug 1924 | Box 72 \ 3 scan0082 | |
| High-speed accident, issues with 4-wheel brakes, and ongoing component tests. | 20th Feb 1924 | Box 72 \ 3 scan0083 | |
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