This post was first published on 16th October, 2014.
The chassis or the frame is part of a vehicle that is of paramount importance. It is like a skeleton that defines the shape of the vehicle and holds all the associated components of the vehicle together. There are different types of motorcycle frames such as single cradle, half duplex cradle, full duplex cradle, perimeter, beam, trellis etc., Though single cradle or single down-tube cradle frame is the simple and most commonly found frame on motorcycles, it is quite inferior to its counterpart in terms of handling.
The Featherbed Frame is a type of full duplex cradle or double down-tube frame, and was invented by Mr. Richard McCandless aka Rex, in the year 1949 for UK based Norton Motorcycle Company. Rex developed the Featherbed Frame for the Norton Motorcycle Company, primarily for improving performance of their racing motorcycles for the Isle of Man TT, as several of Norton’s Garden Gate frame buckled under the extreme stress of racing. The term Featherbed Frame was coined by Mr. Harold Daniell (an elite Isle of Man TT racer who won several trophies during his era) after trying out the new frame developed by Rex. He declared that it was like, “riding on a featherbed” when compared with riding the “garden gate” frame.
The Patent GB664667 A entitled, A new or improved frame for a motorcycle, discloses the features of the featherbed frame. The patent claims a frame for a motorcycle comprising two parallel rectangular loops each formed from a single length of tubing, the ends of the tube which forms each loop crossing and being welded to each other at the top front corner of the loop and the free ends of the tube which extend beyond the crossing point being welded to an inclined head tube adjacent to the top and bottom thereof respectively.
The featherbed frame is extremely stiff and provides excellent resistance to the stress developed due to road conditions, direct load and torque developed by the engine. It delivers excellent manoeuvrability, especially during cornering at high speeds.
The featherbed frame became a standard for Norton’s production motorcycles and has been widely implemented by many motorcycle manufacturers. In fact many hybrid custom motorcycles like TriTon, NorBsa, NorVin etc., were made using Norton’s frame. Recently, Royal Enfield has adopted this frame for its popular product – The Continental GT.