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P41 Interpol II 1985-1989

The Interpol II was a development from the few P39 "Cooke Neilsen" type prototypes that had been converted to a prototype Police specification, utilizing a BMW "RT" type front fairing and the typical Craven pannier Police equipment known from the old "Interpol" Commandos. These bikes had been loaned to some local police forces and had served to iron out bugs in the development that were not aparent to experienced motorcycle testers, but were to become obvious in the not-so-caring, not-so-knowledgeable hands of the average police patrolman. The main difference to the "Cooke Neilsen Interpol" type lay in the new tank/seat units, and in motor management- the electronic ignition now switching from the in-house "Sparkrite"-system to Boyer Bransden. The "single rotor idle" tickover system switching one carburettor off for a slow tickover gave way to a new ignition curve that made slow tickover possible with a heavier flywheel. As Ernie Bransden once complained to the author "They wanted it to run like a tractor at tickover"- which meant he had to take the full advance the engine needed for starting back to full retard immediately for low reves, then advancing rapidly again, which makes for a highly original advance/retard curve!
There were several stories why the BMW fairing was copied- to "disguise it in the early stages of testing", to "make an assembly of police bikes, part BMW, part Norton, look homogenous"- we suspect it was first used on prototypes because it worked and was available, and then Norton stuck to it until they did their own on the "Commander". Police equipment hung off the bike in bolted-on, afterthought-resembling lumps as on the "Commando Interpol" of old- again, this was taken at least a full generation forward on the "Commander".