Bearing in mind the situation with Wipac rotors on the lightweights ie 1" crank. A O services is doing a special offer to get some/any rotors re-magnetised. This can include the Lucas item but bear in mind these are available new.
Please get in touch direct.
Not so, again
The Wipac rotor fitted to our lightweights has a bore of 31/32". This idea of the rotors being 1" has been going around for years, I would have thought that would have been laid to rest years ago.
As for fitting Lucas equipment to the lightweight, what's that on the end of my Navigator crank shaft?
Incidentally, the bore of Lucas rotors has got bigger than it used to be. Not much, only 0.001" - 0.0015". Only reason I can think of for this is to make it easier to fit to a shaft, they were a good tight fit on the shaft, not so tight now. This may have happened when the original Lucas stopped making them and Wassell's started making them? I've also noticed the depth of the keyway in the rotor has varied somewhat.
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Wipac Rotors
Hi John, I don't know where you got the 31/32" bore measurement for the Wipac Rotor from - but it certainly looks about right.
The finished diameter of the crank is 0.9670" - 0.9675".
So, if the Rotor bore size is 31/32" (which is 0.96875") - it gives us a sliding fit of about 1 thou, depending on the Rotor tolerances... (Have you seen a drawing?).
My next question is - how did you get a Lucas Rotor to fit your Jubilee/Navi/Electra?
It has long been known that a Lucas Stator will fit over a Wipac Rotor - but the air gap is larger, so the power produced is less. And I have yet to see a Lucas Rotor of the right size?
But you seem to have overcome that??
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Crank shaft diameter
Andy, I measured the lightweight cranks I have. I've quoted nominal size, as we do with the 3/4" bore Lucas rotors. Looking at your exact sizes, I would guess the rotor bore size would be size + 0.005" to give the required fit without the need for selective assembly
Not seen a drawing of the Wipac rotor. Its my inner pedant that gets annoyed when the wrong size is quoted!
As for how I fitted the Lucas 3/4" bore rotor, I don't want say just yet, I've only done a few hundred miles on the bike, plenty of time for disaster to strike. I will say I didn't bore a rotor to fit. That idea, I have read, has been dismissed as not being feasible. I'm not so sure about that, it may be just possible to open out the bore enough and get a keyway in to it to fit a lightweight.
I've made a number of significant modifications to my Navigator engine, when I've proved to myself all is well (or not!) I'll write something about them for "Roadholder".
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A useful service, thanks.
The alternative is to fit Lucas parts......