Ride-height reduction is a popular upgrade across the classic-MG range, particularly on rubber-bumper cars where the original raised ride height, introduced to satisfy headlight-height and bumper-height regulations of the period, compromises the visual proportions of the car and raises the centre of gravity in a way the chassis was never designed around. The rubber-bumper cars sit approximately one and a half inches higher than the chrome-bumper cars, the increase resulting from a raised front crossmember, stiffened rear springs, lowered rear spring hangers, and revised shock-absorber links, with the effect on handling being significant as the higher centre of gravity increased body roll and the softer damping introduced at the same time compounded the problem. Lowering a rubber-bumper car back to chrome-bumper ride height is one of the most effective single improvements to both the car's appearance and its handling, and lowering blocks and lowered springs offer two principal approaches with different trade-offs.
Rear Lowering Blocks
Rear lowering blocks are wedge-shaped or rectangular blocks fitted between the rear axle and the leaf spring, with the U-bolts passing through the block to clamp the assembly, the effect being to lower the body relative to the axle while the axle and spring stay in their original positions, the body sitting lower by the thickness of the block. 1-inch lowering blocks are the standard stocked size, originally specified as a Special Tuning option and now the conventional choice for owners reducing rubber-bumper ride height to approximate the original chrome-bumper proportions, with larger 2-inch blocks available for more substantial reductions. The blocks are supplied with elongated U-bolts to suit the increased clamping distance and with the appropriate locknut hardware, and are a straightforward and reversible modification that can be used independently or in combination with uprated front springs for a balanced drop, with kits available for both banjo-axle and tube-axle cars. Lowering blocks affect the geometry of the leaf-spring shackles and the propshaft angle, so very substantial blocks above 2 inches typically require supporting modifications to keep the geometry within acceptable limits.
Lowered Springs & Complete Kits
Lowered springs are the alternative approach, replacement springs with reduced free length producing the lower ride height while keeping the spring stiffness in a controlled range, stocked for both ends of the car as uprated front coil springs that replace the original front coils and lowered leaf springs for the rear. The advantage of lowered springs over blocks is that the suspension geometry is better preserved, while the disadvantage is cost. Uprated front coil springs originally part of the factory Special Tuning programme provide a matched front-end drop with firmer suspension control, standard uprated road springs rated at 480lb lowering the front by approximately one inch on chrome-bumper cars and two inches on rubber-bumper models, while fast-road springs at 550lb drop the chrome-bumper front by approximately 1¼ inches and the rubber-bumper front by approximately 2¼ inches, further reducing body roll and improving turn-in response. The most comprehensive approach is the complete lowering kit which replaces both front and rear springs to reduce ride height effectively to chrome-bumper levels, available for rubber-bumper and chrome-bumper applications, the chrome-bumper kits providing a modest further reduction on cars already at the standard ride height.
Supporting Modifications & Geometry
Lowering blocks and lowered springs can be combined, fitting a 1-inch rear block alongside lowered front springs giving a substantial overall reduction while keeping the cost lower than a full lowered-spring set. Supporting modifications typically needed alongside any lowering work include uprated dampers, as the standard lever-arm dampers may bottom out more frequently with reduced ride height, and when lowering a rubber-bumper car with lever-arm dampers retained, chrome-bumper-type shock-absorber link arms must be fitted, as the rubber-bumper link arms are longer to suit the raised ride height and will not provide the correct geometry at the lowered position. In some cases, fitting shorter bump stops or small spacers may be necessary to prevent the suspension sitting on its stops after lowering, particularly relevant on rubber-bumper cars where the total front drop with fast-road springs exceeds two inches. Other supporting work includes adjustment of the brake-line clip positions where the lowered axle pulls the brake hose taut, and the front suspension geometry should be checked and reset after any lowering, as the altered ride height changes the camber and castor angles and the bump-steer characteristics.
The technical team is available to advise on the right combination of components for a specific car and intended use.