Flashers and simplicity

Near the finish of its rebuild, the 1966 BSA A50’s rewire begins. At first glance, the machine’s original main loom looked sound, then extra wires and a handful of coloured, automotive connectors were spotted. Anything of any use was snipped from the loom and the rest was confined to the bin.

The Beesa’s role will include trips into Cambridge, Peterborough, Ely etc where

60% of car drivers and almost all cyclists in the cities don’t see hand signals by motorcyclists, and if they do, they don’t understand them. In fact, part of the Cambridge city cyclists’ manual must include NEVER signal or glance behind and ALWAYS ride across and in front of cars, lorries, motorcycles et al, regardless of who has the right of way. Thus, to help all (well, Peter and I as its users) the

A50 is getting a set of direction indication flashers – flashers from now on.

Along with adding flashers, it made sense to modernise its 12V rectifier and control system to a solid state all-in-one unit, as fitted to most modern machines for the past 40-plus years, and do away with the positive earth rectifier and Zenor diode, along with its heat sink plate.

Rectifier/voltage regulator

A small range of makers manufacture these which are available for single phase and three phase alternators and 120W to 200W. It is possible to source second-hand items from bike breakers, but the new units are relatively inexpensive, so I wanted to fit new.

They can be employed to directly replace plate type or solid state rectifiers, the voltage controlling Zenor diode and finned or flat plate heat sinks. The rectifier/regulator unit used for the BSA is suitable for both positive and negative earth 12 applications (the subject

BSA A50 is 12V positive earth) and single phase units can be employed to convert 6V, three lead stators to suit 12V electrics, but we aren’t needing to worry about such here; however, makers’ instruction sheets will provide more details.

Left: It is bad practice to hide units containing diodes out of airstreams and in this case atop the BSA A50’s oil tank. For years, I’ve been threatened with tales of doom and fried diodes in the units containing the same, and, for years, I haven’t listened and nothing has happened, even on long, high speed runs. My excuse for committing this grievous misdemeanour is I like neat electrics/ motorcycles and despise electrical bits hung from frames, steering heads and elsewhere, even if this puts them in the airstream. Thus, after some effort to condense the electrics, they are mounted to a plate, insulated from the oil tank with rubber, then fitted under the seat. Visible in the picture are the rectifier/regulator, new old stock 12V Lucas flasher unit and earth tower, which is connected via a fuse to the battery, mounted alongside the oil tank and under a removable bodywork panel.

Above: Maker supplied wiring diagram for the rectifier/regulator unit. While the wiring diagram was clear and easy to follow it was also tiny, and when enlarged, it is fuzzy. A Sherlock Holmes-esque magnifying glass proved perfect here!