Perfidious Albion

tatty500

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Non-VOC Member
But your initial post said:

"For one turn of the gearbox sprocket shaft the following turns of the clutch shaft(approximate)

Top 1.75

Third 1.33

Second 1.2

First 1.0"


So, the initial measurements must have the gears in reverse order.
Tatty
 

vibrac

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VOC Member
But your initial post said:

"For one turn of the gearbox sprocket shaft the following turns of the clutch shaft(approximate)

Top 1.75

Third 1.33

Second 1.2

First 1.0"


So, the initial measurements must have the gears in reverse order.
Tatty
Thats right
 

Howard

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Tim, I'm not sure what box the Comet Special and TT Rep used, but Richardson shows the ratios as 1:1, 1:1.16, 1:1.45 and 1:1.82 - close(ish) to what you've measured. ie Top 1:1 third 1:1.3 second 1: 1.4 bottom 1:1.75

H
 

vibrac

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bottoms.jpg

Here are the bottom gear set that was in my box No3 (top) and the 'standard' bottom gear set I have taken from my Albion gear cache (bottom)
As I suspected i8/30 is the nearest I can do against a 19/29 of the No5 box generally used on the original Grey Flash. I think that one tooth will not matter too much. A point to note with these boxes is that the smaller gear is often (for example on the standard set) the same tooth count as on the mainshaft top gear and at first glance they look identical but only one gear has a slightly raised edge (visible in the top small gear) this can be used on either shaft but one with a raised edge must be used on the layshaft (pointing away from the sprocket end).Why did Albion not produce both the gears with the raised edge you may well ask..yes indeed,why not? thats why I call them perfidious:)
I will now assemble the box, workout the overall ratios and this time sort out a chart of speeds in the gears against rear sprocket sizes
 

vibrac

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It is a good measure that I have too many bikes when I finally get to looking at the clutch failure on my Flash that occured at the flywheel meeting last summer
Its not the quick job I first thought. The 'top hat' adjuster on the RH side under the operating lever was difficult to remove and I found some friction welded 'thing' on the screw end (perhaps it was an unhardened adjusting screw?) the push rod is immovable in the shaft it does not look to mushroomed but it will not move a good poke from the clutch side will not move the rod either.
Thats enough scrabbling about on the floor I will get it up on the bench when I get the new rear units for the Egli Comet that hangs suspended there after suspension calculations.
Does anyone know the diameter of the clutch push rod? I have a dim recollection of 1/4" even dimmer is if it was in two parts with a ball or roller between.
ADDED content : the top hat contained a reasonable screw and the funny thing was a ball bearing welded to a push rod end so the trouble must be upstream the clutch end looks fine somethings jammed the rod in the shaft....
26786
 
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Black Flash

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Hello vibrac,
I have replaced standard shafts with longer commando shafts on two norton boxes to suit usage in a comet. The shafts were centre drilled from both ends and the holes did not meat head on. 1/4 pushrods always had too much friction for my liking.
On fleebay I could buy 6 mm silver steel rods at a very good price, cut to size clean the ends, heat with a blow torch and quench.
With this little extra clearance of 15 thou or so the clutch action was vastly improved. I have yet to see a mushroomed silver steel rod.
Just a hint while you are at rebuilding your box.
Bernd
 

vibrac

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VOC Member
That was my thoughts for once I shall go metrico_O. of course first I have the task of extracting the rod when I get my bench back I shall try from the clutch side after cleaning up the end. I once manage to drill down the entire length of a 1/4" broken rear wheel adjusting screw without hurting the thread in the casting I dont think I would get away with the length of a mainshaft:eek:
Silver steel - I just ask Mallard metals for a length :D
 
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