A shortened Herald chassis with a Michelotti body — and a rear suspension that changed twice.
The Spitfire is a shortened Triumph Herald chassis with Herald running gear, body-on-frame, with structural outer sills added to stiffen it. Unlike the Herald it had front disc brakes from the Mk I — the little sports car got them before the saloon it was based on. Engines run 1,147cc for the Mk I and Mk II, 1,296cc for the Mk III and Mk IV, and 1,493cc for the 1500, which is the same Standard SC unit that ended up in the MG Midget 1500. Nearly 96,000 of the 1500s were built, making it the most numerous of the lot.
The rear suspension is where the money is. Mk I, Mk II and Mk III all use the Herald-type swing axle on a transverse leaf spring, with the same camber change and the same reputation for lifting a wheel and snapping into oversteer. The Mk IV of November 1970 introduced the “swing spring”: a leaf was removed, and instead of the whole stack being clamped to the differential only the bottom leaf is clamped, with the leaves above it free to pivot, so the spring rocks as a unit and the jacking effect goes away. The 1500 went further again with longer swing axles and a lowered spring mounting, giving a wider track and more negative camber. This is the cheap fix; the Vitesse Mk2 and GT6 Mk2 got the expensive one, with Rotoflex wishbones. The two solutions share no parts.
Triumph Spitfire — specification & changes within the model
- Mk I
- October 1962 – December 1964. 1,147cc, 63bhp. 45,753 built. Front disc brakes from the start.
- Mk II
- December 1964 – January 1967. 1,147cc, 67bhp. 37,409 built.
- Mk III
- January 1967 – December 1970. 1,296cc, 75bhp. 65,320 built.
- Mk IV
- November 1970 – December 1974. 1,296cc, 63bhp. 70,021 built. The swing spring arrives here.
- 1500
- December 1974 – August 1980. 1,493cc, 71bhp. 95,829 built — the most numerous Spitfire.
- Rear suspension — the two changes
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Mk I, II and III: Herald swing axle on a transverse leaf spring. Mk IV, November 1970: the swing spring — one leaf removed, only the bottom leaf clamped to the differential, the rest free to pivot. 1500: longer swing axles and a lowered spring mounting, wider track, more negative camber.
- The other fix
- The Vitesse Mk2 and GT6 Mk2 solved the same problem with reversed lower wishbones and Rotoflex couplings — the expensive way. Swing-spring and Rotoflex parts do not cross.
- Construction
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A shortened Herald chassis with Herald running gear, body on frame, with structural outer sills added to stiffen it. Michelotti body.
- Engine
- Standard SC four throughout. The 1500’s 1,493cc is the same unit as the MG Midget 1500, which is why some parts cross between them.
- Brakes
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Front discs from the Mk I. Disc and drum sizes are not established from a citable source — measure before ordering.
