Carpenter frames were always meticulously mitred, pre-pinned and jig-assembled and low temperature brazed to a conventional format. These were functional but refined racing machines; fashionable elaborations such as curly rear stays, diadrant front forks or over-ornate lugs were eschewed, the focus was entirely on frame geometry that allowed the rider to give of his best. In later years they resisted the growing fashion for ultra-short wheelbase designs for time-trial bikes, favouring the stability benefits that came from conventional bike lengths and slim seat stays.
As soon as High-Manganese “HM” butted tubesets became available from Reynolds these were the basis of the frames. Once lighter “531” tubing came on the market in the mid-1930s this was quickly adopted and remained the the sole basis for the rest of the existence of the marque.
Frames were serially numbered, 4 digits stamped on the bottom bracket shell and fork steer tube. From this, frames dates can be estimated here.