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).
Increasing clearance by modifying the off-side rear wheel arch on chassis 20-EX.
| Identifier | ExFiles\Box 14\8\ Scan169 | |
| Date | 1st October 1929 guessed | |
| -2- car is unloaded than when carrying its full complement of passengers. Possibly due to the rear springs offering greater resistance to twisting when under heavy load, thus restricting the roll somewhat. The rear springs twist as much as 10° (between the rear spring eye and the axle fixing) when the car is rolling. On N. Sch. 2938. Da{Bernard Day - Chassis Design}/HV has indicated the extreme case possible on these cars, it is obvious that this cannot be catered for owing to the big reduction in seating width which it entails. It appears that the only way to fix the clearance which will be generally satisfactory, is to increase the clearance appreciably and then find out what conditions are necessary to produce fouling with this additional clearance. On 20-EX off side rear wheel arch we have increased the clearance as follows, which is the maximum we should care to recommend without altering the subframe :- The bottom flange of the subframe was cut back 1/4" the top flange 1/2", the line joining these two points being carried up to the brake drum clearance arch. These two dimensions are in line with the centre of the axle and extend 5" either side of the centre when they merge into the original arch. This involves reducing the rear subframe support bracket slightly. The remainder of the wheel arch is unaltered so that the width of seating accomodation is not reduced. The extra depth of brake drum arch clearance | ||