| Description | Date | Identifier | |
| Order of tyres from Messrs. Dunlop for a 20 HP model. | 15th Mar 1927 | Box 45 \ 2 Scan022 | |
| Letter to The Dunlop Rubber Co. postponing a car demonstration. | 16th Mar 1927 | Box 45 \ 2 Scan023 | |
| Delivery note from The Derby Vulcanizing Co. for two Dunlop tyres. | 31th Mar 1927 | Box 45 \ 2 Scan024 | |
| The safety of using smaller wheels and tyres on the 20 HP model due to ground clearance issues. | 21th Apr 1927 | Box 45 \ 2 Scan025 | |
| Letter from Dunlop Rubber Co. discussing the implications of smaller diameter wheels and tyres on tyre mileage for the 20 HP car. | 13th Apr 1927 | Box 45 \ 2 Scan026 | |
| Technical and economic considerations of fitting low-pressure tyres to existing cars. | 22th Apr 1927 | Box 45 \ 2 Scan027 | |
| Cost of wheels and tyres on existing cars. | 29th Apr 1927 | Box 45 \ 2 Scan028 | |
| Letter to Dunlop Rubber Co. enquiring about the rolling circumference of a 19' rim with 6' tyres for a 20 HP car. | 28th Apr 1927 | Box 45 \ 2 Scan029 | |
| Adopting standard Dunlop tyres and testing tread patterns for noise on Phantom and 20 HP models. | 1st May 1927 | Box 45 \ 2 Scan030 | |
| The expected delivery of 6' section tyres and ordering of new Dunlop studded tread tyres. | 7th May 1927 | Box 45 \ 2 Scan031 | |
| Introducing Buttressed Tread Covers for 'Phantom' and 20-HP chassis, detailing Dunlop's stock and querying Bentley's tyre usage. | 18th May 1927 | Box 45 \ 2 Scan032 | |
| Stock levels of Dunlop tyres for 20 HP and 40/50 HP models. | 17th May 1927 | Box 45 \ 2 Scan033 | |
| The standardization of the Buttress type tyre tread for 20 HP & 40/50 HP chassis. | 19th May 1927 | Box 45 \ 2 Scan034 | |
| Recommendation on tyre selection and wear in relation to heavy steering on 40/50 HP and 20 HP models. | 23th Jun 1927 | Box 45 \ 2 Scan035 | |
| Order for Dunlop tyres and inner tubes. | 15th Jul 1927 | Box 45 \ 2 Scan036 | |
| Listing the weights of various tyres and wheel combinations. | 18th Aug 1927 | Box 45 \ 2 Scan037 | |
| Internal request to order tyres and tubes from Messrs. Dunlops. | 18th Aug 1927 | Box 45 \ 2 Scan038 | |
| Order for tyres and inner tubes for a 20 HP car. | 27th Aug 1927 | Box 45 \ 2 Scan039 | |
| Comparing the tyre removal features of Michelin and Dunlop wheels and proposing a new two-depression rim design. | 27th Oct 1931 | Box 45 \ 2 Scan040 | |
| Requesting a set of British Goodrich tyres due to dissatisfaction with noise from Dunlop tyres. | 14th Nov 1927 | Box 45 \ 2 Scan041 | |
| Comparing the average mileage of well base tyres against straight sided cord tyres. | 17th Nov 1927 | Box 45 \ 2 Scan042 | |
| Request for tyre performance data, specifically m.p.h. at 1000 r.p.m. for various tyre and wheel combinations. | 11th Nov 1927 | Box 45 \ 2 Scan043 | |
| Results of a test on noisy tyres from chassis No. 62-LF. | 25th Nov 1927 | Box 45 \ 2 Scan044 | |
| Performance comparison memo between Michelin Comfort Bibendum and Dunlop tyres. | 29th Nov 1927 | Box 45 \ 2 Scan045 | |
| Comparison of 'Traction' and 'Buttress' tyre treads, noting noise and vibration characteristics. | 30th Nov 1927 | Box 45 \ 2 Scan046 | |
| Analysis of uneven tyre tread wear, its causes, and its relationship to transmission vibration. | 30th Nov 1927 | Box 45 \ 2 Scan047 | |
| Drawing illustrating the profile and tread of a wheel and tyre. | 12th Dec 1927 | Box 45 \ 2 Scan048 | |
| Tyre noise and vibration issues with various tyre brands like Michelin and Dunlop. | 12th Dec 1927 | Box 45 \ 2 Scan049 | |
| Explaining variations in tyre rolling diameters and their 5% effect on the effective gear ratio. | 3rd Dec 1927 | Box 45 \ 2 Scan050 | |
| Comparison of road speeds using various tyre types and pressures for different car models. | 8th Dec 1927 | Box 45 \ 2 Scan051 | |
| Short test on British Goodrich tyres, noting their quietness compared to Dunlop tyres. | 9th Dec 1927 | Box 45 \ 2 Scan052 | |
| Letter to Dunlop Ltd. arranging a visit to discuss alternative tyres and the use of rubber blocks in chassis construction. | 17th Dec 1927 | Box 45 \ 2 Scan053 | |
| Performance and noise characteristics of Dunlop tyres, particularly a low-speed shudder. | 2nd Jan 1928 | Box 45 \ 2 Scan054 | |
| The disposal of four used Buttressed Tread type tyres removed from vehicle GRJ-45. | 12th Jan 1928 | Box 45 \ 2 Scan055 | |
| Development of a quieter, but less safe, tyre with Dunlop. | 25th Jan 1928 | Box 45 \ 2 Scan056 | |
| Performance of Dunlop Triple Stud tyres, particularly their non-skid capabilities on rough roads. | 2nd Feb 1928 | Box 45 \ 2 Scan057 | |
| Letter from Dunlop Rubber Co. Ltd. regarding the dispatch and testing of special tread tyres for noise reduction. | 7th Feb 1928 | Box 45 \ 2 Scan058 | |
| Problem of excessive tyre noise from Dunlop Triple Stud tyres on smooth roads. | 7th Feb 1928 | Box 45 \ 2 Scan059 | |
| Initial testing of new silent Dunlop tyres on a 40/50 HP vehicle. | 10th Feb 1928 | Box 45 \ 2 Scan060 | |
| Letter to Dunlop requesting a second set of new tyres for parallel testing. | 11th Feb 1928 | Box 45 \ 2 Scan061 | |
| Brief typed memo regarding new Dunlop tyres, acknowledging a previous note and requesting a further report. | 13th Feb 1928 | Box 45 \ 2 Scan062 | |
| Letter from Dunlop Rubber Co., Ltd. concerning an order for special tyres for testing and requesting feedback on noise. | 15th Feb 1928 | Box 45 \ 2 Scan063 | |
| Letter to the Dunlop Rubber Co. providing initial feedback on the silence of submitted tyres. | 16th Feb 1928 | Box 45 \ 2 Scan064 | |
| Private letter regarding variation in tyre wear and the use of smaller wheels on the 20 HP model. | 13th Mar 1928 | Box 45 \ 2 Scan065 | |
| Inquiry to the Dunlop Company regarding the development and potential future requirements for a silent tread tyre. | 27th Mar 1928 | Box 45 \ 2 Scan066 | |
| Performance and fitting of new, quieter Dunlop tyres compared to the older buttress tread design. | 28th Mar 1928 | Box 45 \ 2 Scan067 | |
| Brief internal memo agreeing to take a matter up with Dunlops. | 11th Apr 1928 | Box 45 \ 2 Scan068 | |
| Various tyre and rim options for the 20 HP car, requesting rolling circumference data for comparison. | 22th May 1928 | Box 45 \ 2 Scan069 | |
| 20 HP axle ratios and tyre sizes, expressing reluctance to introduce a new tyre size. | 23th May 1928 | Box 45 \ 2 Scan070 | |
| Letter to The Dunlop Rubber Co. regarding a matter involving Sir Reginald Ford and a representative in Bombay. | 4th Jun 1928 | Box 45 \ 2 Scan071 | |
| Typed extract of a letter regarding complaints about the poor performance of balloon tyres for cross country work. | 4th Jun 1928 | Box 45 \ 2 Scan072 | |
| Cover page for a pamphlet from The Rubber Association of America regarding the reasons for variation in tire wear. | 4th Jun 1928 | Box 45 \ 2 Scan073 | |
| Paper discussing the various factors that cause variation in tire wear, such as speed and temperature. | 4th Jun 1928 | Box 45 \ 2 Scan074 | |
| Technical analysis of factors contributing to automobile tire wear. | 1st Dec 1927 | Box 45 \ 2 Scan075 | |
| Study on excessive tire wear causes, including brake adjustment and misalignment, with a data table on estimated mileage in Detroit and Buffalo. | 1st Dec 1927 | Box 45 \ 2 Scan076 | |
| Letter from Dunlop Rubber Co. Ltd. regarding the specifications and availability of 6.00 inch tyres for 20 and 21 inch rims. | 18th Jul 1923 | Box 45 \ 2 Scan077 | |
| Telegram from Royce to Roycar-Derby requesting the urgent supply of wheels and tyres. | 23th Jul 1928 | Box 45 \ 2 Scan078 | |
| Order for tyres and tubes from Dunlops to be fitted and delivered to Conduit Street. | 26th Jul 1928 | Box 45 \ 2 Scan079 | |
| Order for a set of complete silent tread tyres for a 40/50 HP car. | 26th Jul 1928 | Box 45 \ 2 Scan080 | |
| The weights of various 20 HP wheel and tyre combinations. | 19th Aug 1928 | Box 45 \ 2 Scan081 | |
| Letter to Dunlop Rubber Co. regarding inconsistencies in tyre dimensions and specifications. | 21th Aug 1928 | Box 45 \ 2 Scan082 | |
| Specification table for Dunlop wheels and tyres. | 1st Sep 1928 | Box 45 \ 2 Scan083 | |
| Order for three 6.75' silent tread tyres from Messrs. Dunlops for a 40/50 HP car. | 1st Sep 1928 | Box 45 \ 2 Scan084 | |
| Letter to Dunlop Rubber Co. regarding the supply and specifications of tyres and wheels for a 40/50 HP car. | 25th Sep 1928 | Box 45 \ 2 Scan085 | |
| Visit to Dunlop Rubber Co. concerning new 'Fort' and 'Super' model tyres. | 25th Sep 1928 | Box 45 \ 2 Scan086 | |
| Tyre performance regarding 'shimmy', and issues with rubber engine feet and cylinder joints. | 28th Sep 1928 | Box 45 \ 2 Scan087 | |
| Letter to Dunlop Rubber Co. Ltd. requesting silent tread tyres for 'shimmy' tests. | 28th Sep 1928 | Box 45 \ 2 Scan088 | |
| Solutions for harsh riding, focusing on spring selection, weight distribution, and tyre types. | 1st Oct 1928 | Box 45 \ 2 Scan089 | |
| Letter to Dunlop Rubber Co. regarding a request from Mr. Royce for a set of silent tread tyres for his 20HP car. | 3rd Oct 1928 | Box 45 \ 2 Scan090 | |
| Fitting of new silent tyres to trials cars. | 4th Oct 1928 | Box 45 \ 2 Scan091 | |
| Letter from Dunlop Rubber Co. Ltd. discussing tyre specifications and alternatives due to fitting difficulties. | 4th Oct 1928 | Box 45 \ 2 Scan092 | |
| Continuation sheet of a letter concerning supply arrangements and an enquiry from Paris. | 5th Oct 1928 | Box 45 \ 2 Scan093 | |
| Letter to Dunlop Rubber Co. regarding tyre comparison tests for a 40/50 HP car. | 5th Oct 1928 | Box 45 \ 2 Scan094 | |
| Selecting the quietest and most flexible tyres, with sizes specified for Phantom, 20 HP, 'SS', and India models. | 6th Oct 1928 | Box 45 \ 2 Scan095 | |
| The introduction and performance of silent tread tyres on Phantom and 20 HP cars. | 9th Oct 1928 | Box 45 \ 2 Scan096 | |
| Letter from Dunlop regarding the supply and production status of various tyre types for testing. | 10th Oct 1928 | Box 45 \ 2 Scan097 | |
| Letter from The Dunlop Rubber Co. Ltd. regarding the inclusion of certain tyres in the Dunlop France programme. | 10th Oct 1928 | Box 45 \ 2 Scan098 | |
| Letter to The Dunlop Rubber Co. inquiring about the availability of standard 'Fort' tyres and super tyres for testing. | 17th Oct 1926 | Box 45 \ 2 Scan099 | |
| Letter from Dunlop Rubber Co. Ltd. concerning the manufacture and availability of Fort and Super tyres. | 19th Oct 1928 | Box 45 \ 2 Scan100 | |
| Letter to the Dunlop Rubber Co. Ltd. concerning the poor mileage of silent tread tyres. | 23th Oct 1928 | Box 45 \ 2 Scan101 | |
| Letter to Dunlop Rubber Co. regarding poor road grip from triple stud tyres and enquiring about re-treading options. | 23th Oct 1928 | Box 45 \ 2 Scan102 | |
| Incorrect tyre delivery from the Dunlop Rubber Co. and a request for improved communication. | 23th Oct 1928 | Box 45 \ 2 Scan103 | |
| Comparing the mileage of Silent Tread tyres against triple studded tyres. | 24th Oct 1928 | Box 45 \ 2 Scan104 | |
| Letter from Dunlop Rubber Co. Ltd. to W.A. Robotham confirming a meeting and acknowledging receipt of previous correspondence. | 25th Oct 1928 | Box 45 \ 2 Scan105 | |
| Explaining the difficulties in ordering experimental tyres from Dunlop. | 26th Oct 1928 | Box 45 \ 2 Scan106 | |
| Letter to The Dunlop Rubber Co. confirming a meeting time and date. | 29th Oct 1928 | Box 45 \ 2 Scan107 | |
| Meeting with Dunlop to discuss tyre tread life, safety on wet roads, and development of new tyres. | 2nd Nov 1928 | Box 45 \ 2 Scan108 | |
| Continued discussion on testing experimental rubber mixings for the 40/50 load. | 29th Oct 1928 | Box 45 \ 2 Scan109 | |
| Letter from Dunlop regarding a delay in the supply of Silent Tread Tyres. | 29th Oct 1928 | Box 45 \ 2 Scan110 | |
| Letter to a customer regarding skidding issues with his 20 HP car's Dunlop tyres, recommending re-treading. | 2nd Nov 1928 | Box 45 \ 2 Scan111 | |
| Letter discussing a customer's complaint about Dunlop tyres skidding and the potential for re-treading. | 1st Nov 1928 | Box 45 \ 2 Scan112 | |
| Production of a replica 'Fort' non-skid tyre, questioning the decision as it seems to contradict previous efforts with Dunlop's to create a silent tread tyre. | 7th Nov 1928 | Box 45 \ 2 Scan113 | |
| Clarifying that the term 'Fort' refers to tyre dimensions, in response to a previous query. | 8th Nov 1928 | Box 45 \ 2 Scan114 | |
| Letter to Dunlop Rubber Co. Ltd. requesting the earliest delivery date for an urgent tyre order for Mr. Royce's car. | 8th Nov 1928 | Box 45 \ 2 Scan115 | |
| Query regarding the delayed delivery of Silent Tread Tyres from Dunlop for an S.S. Chassis. | 13th Nov 1928 | Box 45 \ 2 Scan116 | |
| Letter from Dunlop Rubber Co. Ltd. regarding a delay in the delivery of 32 x 6.75 Silent tyres. | 12th Nov 1928 | Box 45 \ 2 Scan117 | |
| Letter from Dunlop Rubber Co. Ltd. explaining a delivery delay for Silent Tread Tyres due to porosity in the mould material. | 23th Nov 1928 | Box 45 \ 2 Scan118 | |
| The delay in delivery of silent tread tyres for 19' rims due to faulty moulds from Dunlops. | 24th Nov 1928 | Box 45 \ 2 Scan119 | |
| Letter to the Dunlop Rubber Co. regarding the unavailability and delivery of silent tread tyres. | 26th Nov 1928 | Box 45 \ 2 Scan120 | |
| The performance and mileage testing of Goodrich tyres, comparing them with Dunlop tyres. | 1st Dec 1928 | Box 45 \ 2 Scan121 | |
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