During 1927 Charles Van Eugen convinced the directors of Lea-Francis to allow him to design a completely new chassis assembly. Incorporating semi-elliptic springs front and rear the new chassis was longer and with a wider track than previous models. The trailing end of the springs was mounted in such a way that it slid in bronze trunnions, which were themselves able to rotate in their mounting. When well maintained this arrangement gave the new chassis a good ride quality and comparatively good road-holding for the period. The spur gear differential was gone in favour of a bevel gear version and torque reaction was now taken by the rear springs. The hand brake no longer operated on the transmission but instead through a second set of shoes in each of the rear brake drums. The radiator, while retaining the distinctive shape was taller and higher. A new plate clutch was designed which was eventually fitted to all cars on the new chassis when fitted with a Meadows 4ED engine.
This new chassis fitted with the 1.5 litre Meadows 4EC engine was designated the U Type. Fitted with a standard single port Meadows 4ED engine it was designated the P Type and with the twin-port Brooklands version of the Meadows 4ED engine the O Type. This chassis frame would also form the basis for that used on famous Hyper or S Type, the V Type and W Type. Made 3” longer the frame was also used as the basis for the T Type .
The U Type with its 12/22 Meadows 4EC engine was almost universally fitted with a wide-ratio gearbox and, for the most part, continued to use the Lea-Francis cone clutch. Disc wheels were initially fitted to most cars, although knock-on Rudge-Whitworth type wire wheels were an option at the start and more or less standard on later cars. Bodies fitted to the U type were mostly 4 seaters by Avon with 2 seater and coupe bodies by Cross & Ellis who also fitted one chassis with a fabric saloon body. Approximately 300 U types were built. However, it is difficult to ascertain the exact figure as a number of chassis laid down as U types left the works as P types, and vice versa. At least nine U types are believed to have survived.