Rectifier regulator unit fitted and A50 in action
Over the last month, I’ve given my
1967 Triumph Tiger 90 the once-over – decoke, new rings, service, replacement alternator and I was going to fit a new rectifier and Zenor. My local motorcycle shop looks after a few classic bikes and recommended that rather than fit the rectifier and Zenor, I should install a rectifier control unit… And, surprise, surprise, they have a spare one in their stores. Are they any good?
Bill Graham, Kempton Park autojumble chat.
I fitted one of these units to my 1966 BSA A50. The machine was bought as a crashedbut-running motorcycle. My son Peter and his wife Rowena sorted out the crash damage and gave it a flit gun paint job, as its role in our lives is as a hack, while
I’ve built the front wheel and rewired it including fitting aftermarket indicators. The plan was to make it into a usable, reliable machine, with good lights and indicators, for trips into Peterborough and Cambridge (where city centre parking costs in excess of £26 for over five hours, while most motorcycle bays are free and devoid of time limits) for under £2500. For once, we were under budget at £2270, but useful new spares including wheel rim, replica mudguard and some fork parts came with the project.
Wanting to keep the electrics as simple as possible, I fitted a rectifier regulator rather than the familiar plate style rectifier and Zenor diode mounted on a finned aluminium heat sink. The Beezer slept for three years before its crash remedial work started. Once completed it started second kick and the ammeter showed an immediate charge, and, with the lights and indicators on, the ammeter needle flicks into the positive zone at an estimated 16001800rpm. Happiness.
Differing rectifier regulator units are available to suit single and three phase alternators and for a range of outputs. Also, the advice leaflet (now thrown away!) informed these units can be employed to convert 6V three-lead alternators (stators) to 12 volts systems and suit both positive and negative earth. These may not suit the originality fiends, but as mine is hidden in free air under the seat, illustrated in an earlier YWA column (November 2021, page 86), they won’t find it.