From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Table detailing specifications and remarks for various front and rear suspension components.
| Identifier | ExFiles\Box 106\1\ scan0336 | |
| Date | 30th November 1932 guessed | |
| TYPE. FRONT. OR REAR. POUNDAGE. HOLES IN VALVES. EQUIV. AREA SQ. INS. REMARKS. UP. DWN. NO. DIA. CP-20 Front. 75 95 1 .031 .000755 20/25 HP. Standard Springs. Good all round suspension with well lubricated springs. CR{Mr Cra???ster / Mr Chichester}-20 Rear. BP-20 Front. 90 115 2 .039 .00239 20/25 HP. Low Rating Springs. Max. freedom suitable for town carriage and old ladies etc. BR-20 Rear. 90 115 1 .031 .00314 BP-20A Front 90 115 1 .044 .00152 20/25 HP. Low Rating Springs. Provides additional damping to improve riding at speed. BR-20A Rear 90 115 2 .039 .00239 AP. Front. 120 120 2 .031 .00151 Phantom I. Best combination for use with plated and grooved springs. AR-2 Rear. 80 100 2 .031 .00151 AR-5 Rear 100 100 - NONE - --- P.II. Provides additional damping to reduce bouncing etc. BP-5 Front 110 110 1 .039 .00119 P.II. Low Rating Springs. Suitable for town carriage, old ladies, and cars for U.S.A. BR-5 Rear 90 115 2 .039 .00239 BP-5A Front 110 110 - NONE - --- P.II Low Rating Springs. Provides maximum damping to improve riding at speed. BR-5A Rear 110 110 - NONE - --- 114/93. | ||