Parabolic rear springs replace the original multi-leaf semi-elliptic springs with a single tapered leaf design. The leaf is thicker in the middle and tapers towards each end, the taper providing the desired progressive stiffness without needing the multiple leaves of the original spring. The single-leaf design eliminates inter-leaf friction, a significant non-linear contributor to ride harshness on the original multi-leaf springs.
Ride Quality
The benefit of parabolic springs is in ride quality. The original multi-leaf springs have static friction between the leaves that resists initial movement, causing the suspension to feel stiff at small inputs and only respond properly at larger ones. The parabolic single-leaf design responds linearly to small inputs as well as large, giving a more compliant ride feel without the on-off character of the multi-leaf spring.
Load Capacity and Geometry
Parabolic springs are designed to match the original spring rate and ride height, so the static geometry of the car is unchanged. They fit using the original mounting points, U-bolts and shackles. Spring length and eye position match the original GT-length specification used on the V8.
Service Life
Parabolic springs typically offer longer service life than multi-leaf originals, with no inter-leaf friction wear and reduced fatigue from the simpler stress patterns in a single-leaf design. They are an upgrade that genuinely improves the car for daily use as well as offering longer service life.
MGOC Spares
MGOC Spares supplies parabolic rear spring kits for the MGB GT V8, with U-bolts and fitting hardware available alongside.