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).
Specification table for various front and rear suspension damper and spring configurations.
| Identifier | ExFiles\Box 105\3\ scan0225 | |
| Date | 6th January 1932 guessed | |
| TYPE. | FRONT OR REAR | POUNDAGE UP | POUNDAGE DOWN | HOLES IN VALVES. NO. | HOLES IN VALVES. DIA. | EQUIV. AREA SQ. INS. | REMARKS. CF-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. BF-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 | 2 1 | .039) .031) | .00314 BF-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 AF | 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 - | — | — | Ph.II. Provides additional damping to reduce bouncing, etc. BF-5 | Front | 110 | 110 | 1 | .039 | .00119 | Ph.II Low Rating Springs. Suitable for town carriage, old ladies, and cars for U.S.A. BR-5 | Rear | 90 | 115 | 2 | .039 | .00239 BF-5A | Front | 110 | 110 | - NONE - | — | — | Ph II Low Rating Springs. Provides maximum damping to improve riding at speed. BR-5A | Rear | 110 | 110 | - NONE - | — | — Hd{Mr Hayward/Mr Huddy}/SB.{Mr Bull/Mr Bannister} | ||