The original inner numbered gearbox case arrived from Kenny yesterday. He had one GBB case in stock GBB 1973 - what was fitted to the bike? GBB 1973, what were the chances of finding the original? The engine and gearbox were built on 17/10/1972. It will now have the correct gearbox to match the engine GPG 3 116.
I am in the process of gathering the correct gears as it is unlikely that it has the correct intermediate or even wide ratio gears. Kenny sent me the spec which Nick Nicholson used;
Per Nick's book you need part # G02961 B ratio gearbox. This is the 30 tooth
six spline PGT gears.
The following gears is what is used in a B ratio six spline...these are the
PGT small pitch gears not the last type with larger teeth.
Main shaft gears as followed,
G02961 PINION 30 T
G02469 PINION 27 T
G02472 PINION 23 T
G02474 PINION 18 T
Layshaft gears
G02475 PINION 18 T
G02470 PINION 21 T
G02467 PINION 25 T
G02477 PINION 30 T
I am still looking for these 3 in the unlikelihood that someone has them on their shelf. (Steve might have these ones, Gary is going to check for me)
I am in the process of gathering the correct gears as it is unlikely that it has the correct intermediate or even wide ratio gears. Kenny sent me the spec which Nick Nicholson used;
Per Nick's book you need part # G02961 B ratio gearbox. This is the 30 tooth
six spline PGT gears.
The following gears is what is used in a B ratio six spline...these are the
PGT small pitch gears not the last type with larger teeth.
Main shaft gears as followed,
G02961 PINION 30 T
G02469 PINION 27 T
G02472 PINION 23 T
G02474 PINION 18 T
Layshaft gears
G02475 PINION 18 T
G02470 PINION 21 T
G02467 PINION 25 T
G02477 PINION 30 T
I am still looking for these 3 in the unlikelihood that someone has them on their shelf. (Steve might have these ones, Gary is going to check for me)
GO2474 - 18T fixed gear.
GO2475 - 18T fixed gear.
GO2470 - 21T Bushed gear
Note*
2 x18t fixed gears -
One is 1st gear mainshaft, it has a shoulder either side of the teeth.
The other is 4th gear layshaft, it has a shoulder on one side, the other side is raised by less than 1mm.
GO2475 - 18T fixed gear.
GO2470 - 21T Bushed gear
Note*
2 x18t fixed gears -
One is 1st gear mainshaft, it has a shoulder either side of the teeth.
The other is 4th gear layshaft, it has a shoulder on one side, the other side is raised by less than 1mm.
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