| Description | Date | Identifier | |
| Letter comparing the performance of Shell and BP petrol, recommending a switch to BP due to better performance in a 20 HP chassis. | 7th Sep 1929 | Box 20 \ 6 Scan100 | |
| To Mr Royce discussing potential causes of failures in ball bearings. | 1st Jun 1911 | Box 20 \ 7 Scan001 | |
| Improving ball bearing cage design to prevent wear and issues under no-load conditions. | 1st Jun 1911 | Box 20 \ 7 Scan002 | |
| Improving ball bearing reliability by fitting rigid cages to prevent foreign matter contamination. | 27th Jun 1911 | Box 20 \ 7 Scan003 | |
| To Mr Johnson discussing the replacement of D.W.M. ball bearings following an enquiry about improvements. | 27th Jun 1911 | Box 20 \ 7 Scan004 | |
| The urgent replacement of faulty ball bearings with sheet metal cages with new cast cage bearings. | 23th Aug 1911 | Box 20 \ 7 Scan005 | |
| Technical paper on the design, load distribution, and stress analysis of ball and roller bearings. | 23th Aug 1911 | Box 20 \ 7 Scan006 | |
| Technical document detailing the formulas and principles for ball bearing design. | 23th Aug 1911 | Box 20 \ 7 Scan007 | |
| Meeting minutes from late 1911 discussing issues with broken, faulty, and replaced ball-bearings. | 23th Oct 1911 | Box 20 \ 7 Scan008 | |
| Meeting minutes from late 1911 discussing the replacement of faulty ball bearings from various suppliers. | 13th Dec 1911 | Box 20 \ 7 Scan009 | |
| Committee discusses a failed front wheel bearing, its cause, and the cost of replacement for a customer. | 27th Oct 1911 | Box 20 \ 7 Scan010 | |
| Instructions regarding the replacement of pressed cage bearings with cast bronze cage bearings for Chassis 1498. | 27th Oct 1911 | Box 20 \ 7 Scan011 | |
| Departmental memo requesting an examination of a customer's front road wheel ball bearing for a guarantee claim. | 3rd Apr 1912 | Box 20 \ 7 Scan012 | |
| Broken front wheel ball bearing from car 1545, seeking an opinion on the cause and liability for replacement. | 4th Apr 1912 | Box 20 \ 7 Scan013 | |
| The causes of failure in ball bearings. | 9th Jun 1912 | Box 20 \ 7 Scan014 | |
| Technical discussion on the causes of failure in ball bearings used in motor car wheels. | 6th Apr 1912 | Box 20 \ 7 Scan015 | |
| Page from 'The Autocar' magazine discussing the performance and design of different types of ball bearings. | 6th Apr 1912 | Box 20 \ 7 Scan016 | |
| Page from 'THE AUTOCAR' magazine discussing vehicle bearings, hubs, and commercial vehicle use. | 6th Apr 1912 | Box 20 \ 7 Scan017 | |
| Notes on the crushing strength of ball bearings and the influence of rotational speed on carrying capacity. | 1st May 1910 | Box 20 \ 7 Scan018 | |
| Instructing the Drawing Office to alter drawings for the end play in gearbox ball bearings as approved by Mr Royce. | 17th Sep 1912 | Box 20 \ 7 Scan019 | |
| The endways clearance for ball bearings in a gearbox. | 19th Sep 1912 | Box 20 \ 7 Scan020 | |
| Special parts, specifically the gearbox with Hoffmann Ball Bearings, fitted to chassis 21COE. | 4th Dec 1912 | Box 20 \ 7 Scan021 | |
| Destructive testing of Hoffmann ball bearings as requested by Mr Royce. | 26th Jun 1914 | Box 20 \ 7 Scan022 | |
| End thrust tests of ball bearings from three different makes. | 26th Jun 1914 | Box 20 \ 7 Scan023 | |
| Test report on a bearing, detailing the condition of the balls and race after a run. | 26th Jun 1914 | Box 20 \ 7 Scan024 | |
| Hand-drawn diagram of a test rig for measuring spring characteristics. | 26th Jun 1914 | Box 20 \ 7 Scan025 | |
| End thrust tests of ball bearings. | 20th Jul 1914 | Box 20 \ 7 Scan026 | |
| The performance and failure analysis of different ball bearings after a series of tests. | 24th Jul 1914 | Box 20 \ 7 Scan027 | |
| The results of an end thrust test for different types of ball bearings. | 24th Jul 1914 | Box 20 \ 7 Scan028 | |
| Letter from Hoffman Manufacturing about their refusal to provide information on special aero ball bearings. | 24th Apr 1910 | Box 20 \ 7 Scan029 | |
| Quality, sourcing, and potential in-house manufacturing of ball bearings for gearboxes. | 15th May 1915 | Box 20 \ 7 Scan030 | |
| The requirement for one or two more race grinders for the plant. | 29th Aug 1938 | Box 20 \ 7 Scan031 | |
| The correct type of Hoffmann front wheel ball bearings to be used, either with or without entrance grooves. | 16th Oct 1919 | Box 20 \ 7 Scan032 | |
| Re-use of 'no-entering slot' type bearings for the front wheel and hub. | 18th Oct 1919 | Box 20 \ 7 Scan033 | |
| Continued memorandum discussing a ruling on the use of an entering slot type of bearing in cars. | 18th Oct 1919 | Box 20 \ 7 Scan034 | |
| Reuse of 'No-entering Slot' type bearings for the chassis front wheel and hub. | 20th Oct 1919 | Box 20 \ 7 Scan035 | |
| Letter from British Timken Limited to W. Hives Esq. of Rolls-Royce's Experimental Department regarding the application of Timken Roller Bearings to front wheels. | 1st Feb 1921 | Box 20 \ 7 Scan036 | |
| Cover of a primer booklet for Timken bearings. | 10th Feb 1921 | Box 20 \ 7 Scan037 | |
| Letter to British Timken Limited regarding the arrangement of front hubs and the use of their bearings. | 10th Feb 1921 | Box 20 \ 7 Scan038 | |
| Use of a Chain Roller Bearing Co. bearing for the back axle pinion of a Goshawk I or II. | 21th Feb 1921 | Box 20 \ 7 Scan039 | |
| Use of Hyatt roller bearings versus plain bearings in gearboxes. | 4th Oct 1921 | Box 20 \ 7 Scan040 | |
| Dynamometer testing of rear foot and hand brakes, noting failures and suggesting design changes. | 8th Oct 1921 | Box 20 \ 7 Scan041 | |
| Testing a noisy Hyatt Roller Bearing and the policy for modifying parts based on successful practices. | 1st Oct 1921 | Box 20 \ 7 Scan042 | |
| Suitability of Michell Thrust Bearings for high-speed applications on a chassis. | 27th Oct 1921 | Box 20 \ 7 Scan043 | |
| Switch from inch to metric-sized ball bearings for American production. | 23th Nov 1921 | Box 20 \ 7 Scan044 | |
| The difficulty of avoiding inch dimensions in designs despite a move towards metric standards. | 23th Nov 1921 | Box 20 \ 7 Scan045 | |
| Letter from the American Bronze Corporation to the Society of Automotive Engineers regarding enclosed data sheets on plain bearings. | 17th Apr 1922 | Box 20 \ 7 Scan046 | |
| Letter from The New Departure Manufacturing Co. announcing the establishment of a direct branch in London. | 22th Nov 1922 | Box 20 \ 7 Scan047 | |
| Trial of a new, cheaper, and better Ball Bearing Grease from a different supplier. | 21th Aug 1923 | Box 20 \ 7 Scan048 | |
| Breakup of a ball bearing supplier monopoly and the subsequent sourcing and pricing strategy. | 26th Aug 1924 | Box 20 \ 7 Scan049 | |
| The performance of special deep groove ball bearings, No. 4747, in the 20 HP clutch withdrawal mechanism. | 27th May 1925 | Box 20 \ 7 Scan050 | |
| Letter from The Hoffman Manufacturing Co. regarding a new design of Ball Journal Cage using milled slots instead of countersunk rivets. | 17th Apr 1925 | Box 20 \ 7 Scan051 | |
| Arranging for the testing of Hoffman Ball Bearings on an experimental car. | 2nd Jul 1925 | Box 20 \ 7 Scan052 | |
| The decision to use high melting-point grease instead of oil for hub lubrication after a conversation with the Hoffmann people. | 17th Mar 1927 | Box 20 \ 7 Scan053 | |
| Report concerning the failure of a Bevel Thrust Bearing on chassis 10.G.III after 10,000 miles. | 16th Jun 1927 | Box 20 \ 7 Scan054 | |
| Proposed modification to the rear axle centre casing, specifically regarding bearings and lightening the differential cage. | 12th Oct 1927 | Box 20 \ 7 Scan055 | |
| Letter to Mr. F.H. Royce regarding stainless steel ball bearings designed for running under water. | 22th Oct 1927 | Box 20 \ 7 Scan056 | |
| Trial of a hypoid axle with a 1' offset and the necessary adaptations for a New Departure bearing. | 14th Jan 1928 | Box 20 \ 7 Scan057 | |
| Choice between Schatz and New Departure bearings with six suggestions for design modification. | 14th Feb 1928 | Box 20 \ 7 Scan058 | |
| Technical note on bearings, oil retention, water exclusion, and a suggestive sketch. | 21th Aug 1928 | Box 20 \ 7 Scan059 | |
| Suggesting the substitution of Belmoline C grease for Duckham's H.B.B. grease for packing ball bearings. | 21th Aug 1928 | Box 20 \ 7 Scan060 | |
| Copy of a letter from Hoffmann Manufacturing Co. Ltd regarding approved bearing lubricants. | 30th Oct 1928 | Box 20 \ 7 Scan061 | |
| The trial of Schubert type angular thrust bearings for India 4 gears. | 30th Oct 1928 | Box 20 \ 7 Scan062 | |
| Letter from The United States Graphite Co. introducing their self-lubricating bearing 'Gramix'. | 15th Dec 1928 | Box 20 \ 7 Scan063 | |
| Promotional tag for GRAMIX self-lubricating bearings. | 15th Feb 1929 | Box 20 \ 7 Scan064 | |
| Modifications to an 'SS' clutch design, referencing bearings from Hoffman and Skefco. | 15th Feb 1929 | Box 20 \ 7 Scan065 | |
| Letter regarding an application from Skefko Company to submit their self-aligning ball-bearings for consideration. | 1st Apr 1912 | Box 20 \ 7 Scan066 | |
| Departmental memo requesting the testing of Skiffco ball bearings. | 4th Apr 1912 | Box 20 \ 7 Scan067 | |
| Requesting an experiment to compare 'Skefko' and 'Hoffmann' ball bearings. | 2nd Sep 1913 | Box 20 \ 7 Scan068 | |
| Requesting experiments with Skefko ball bearings due to issues with Hoffmann bearings. | 2nd Sep 1913 | Box 20 \ 7 Scan069 | |
| Fitting of Skefko ball bearings to the gearbox and rear axle, referencing two production cards and an instruction sheet. | 9th Oct 1913 | Box 20 \ 7 Scan070 | |
| Agreeing to fit Skefko ball bearings to production gear and axle boxes for observation. | 16th Oct 1913 | Box 20 \ 7 Scan071 | |
| Skefko ball bearings for gearboxes and rear axles. | 30th Oct 1913 | Box 20 \ 7 Scan072 | |
| Proposal to return and test Skeffko ball bearings to ascertain the percentage of defects. | 5th Nov 1913 | Box 20 \ 7 Scan073 | |
| Internal memorandum requesting test results for Skefko ball bearings used in the gearbox and hubs. | 12th Nov 1913 | Box 20 \ 7 Scan074 | |
| Extract concerning a 1926 gearbox fitted with Skefko ball bearings. | 14th Nov 1913 | Box 20 \ 7 Scan075 | |
| The failure of Skefko ball bearings during a silence test and requesting a report on the return percentage. | 14th Nov 1913 | Box 20 \ 7 Scan076 | |
| In reply to a query about Skefko Ball Bearings, detailing a report on their silence test performance. | 18th Nov 1913 | Box 20 \ 7 Scan077 | |
| Referencing an extract about fitting Skefko Bearings. | 7th Apr 1914 | Box 20 \ 7 Scan078 | |
| List of experimental parts and modifications fitted to Chassis 58 N A. | 7th Apr 1914 | Box 20 \ 7 Scan079 | |
| Instruction sheet requesting an urgent order for various Skaffko ball bearings for a self-starter motor. | 6th Jun 1914 | Box 20 \ 7 Scan080 | |
| The experimental fitting of Skefko Ball Bearings to various car components. | 18th Jun 1914 | Box 20 \ 7 Scan081 | |
| And response regarding tests on Skefko ball bearings. | 29th Jun 1914 | Box 20 \ 7 Scan082 | |
| End thrust tests of a Skefko ball bearing compared to Hoffman and D.W.F. bearings. | 12th May 1914 | Box 20 \ 7 Scan083 | |
| On the unsuitability of Skefko ball bearings for end pressure applications like road wheels, noting they are noisier than Hoffmann or D.W.F. types. | 10th Jul 1914 | Box 20 \ 7 Scan084 | |
| Instructions to Mr. Mercer regarding Alteration No. 6395, specifying the substitution of ball bearings. | 13th Jul 1914 | Box 20 \ 7 Scan085 | |
| Confirming the removal of Skefko ball bearings from a front axle and steering gear box. | 16th Jul 1914 | Box 20 \ 7 Scan086 | |
| Extract from a report on the end thrust tests of ball bearings. | 24th Jul 1914 | Box 20 \ 7 Scan087 | |
| Summarising the results of an end thrust test on different brands of ball bearings. | 24th Jul 1914 | Box 20 \ 7 Scan088 | |
| Design proposals and bearing modifications for the 'SS' clutch. | 15th Feb 1929 | Box 20 \ 7 Scan089 | |
| The unsuitability of ordinary ball thrust bearings for the Goshawk 11 engine at high speeds. | 26th Oct 1921 | Box 20 \ 7 Scan090 | |
| Request for the results of experiments on different pinion thrust bearings for the Goshawk back axle. | 21th Jul 1922 | Box 20 \ 7 Scan091 | |
| List of parts sent from the United States for experimental work. | 30th Jan 1920 | Box 20 \ 7 Scan092 | |
| List of parts received from Mr. Olley for inspection and testing. | 4th Mar 1920 | Box 20 \ 7 Scan093 | |
| Request for a report on Ball Bearings, attaching a copy of a letter from America. | 11th Aug 1920 | Box 20 \ 7 Scan094 | |
| Letter from Rolls-Royce of America to Claude Johnson requesting test results for Fafnir ball bearings. | 29th Jul 1920 | Box 20 \ 7 Scan095 | |
| Rejecting Fafnir ball bearings due to non-compliance with specifications and excessive noise. | 13th Aug 1920 | Box 20 \ 7 Scan096 | |
| Continuation of a discussion regarding sourcing American equivalent Hoffman bearings and clarifying the total number of bearings in a set. | 13th Aug 1920 | Box 20 \ 7 Scan097 | |
| Unsatisfactory Hess-Bright bearings on gears received from America. | 23th Oct 1918 | Box 20 \ 7 Scan098 | |
| List of parts sent from the United States for which experimental work is required. | 30th Jan 1920 | Box 20 \ 7 Scan099 | |
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