14-09-2020, 09:32 PM
It would be nice to use a period PA, but they are usually horribly expensive.
Other versions, often with an angled drive (not the vertical one the PA has) are usually cheaper.
The PA can be fudged to work at non original revs by changing the spring that controls the movement of the governor weights - the add-on gearbox is a much better way, but I never got round to that on my special, and the home made spring is still in there.
Maybe a simpler way, to get you going, is to fit (say) a Ruby needle type, which are usually cheap and working, and swap the face for(a home made) one with digits in the right place if you need to.
Or, if its a rough one, move the face around until it is correct at 30mph.
Other versions, often with an angled drive (not the vertical one the PA has) are usually cheaper.
The PA can be fudged to work at non original revs by changing the spring that controls the movement of the governor weights - the add-on gearbox is a much better way, but I never got round to that on my special, and the home made spring is still in there.
Maybe a simpler way, to get you going, is to fit (say) a Ruby needle type, which are usually cheap and working, and swap the face for(a home made) one with digits in the right place if you need to.
Or, if its a rough one, move the face around until it is correct at 30mph.