Ways to date your Chopper.
Number one... Is it a MK1 or a MK2?
All 1969 to 1972 MK1 Choppers are easily recognisable for several reasons... (See Major Differences) but the most obvious for instant recognition is the rear frame stay, the tube that goes down from the rear of the seat, (where the Sissy Bar goes in) to the rear wheel bolt.
On a MK1 this piece of tube is straight: And on a MK2 "arrow wedge" frame, this tube is bent at the bottom:

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If you have a MK2 Chopper, it was made between 1972 and end of sales, 1982.

Number two... Rear Hub Date.
All Sturmey Archer 3 speed rear hubs have a date stamped on them... and as 95% of U.K. Choppers have 3 speed rear hubs, this is the best place to look. Stamped into the centre of the rear hub, the large barrel that houses the gears, there is the Sturmey Archer emblem, to one side of that, running left spokeside to right spokeside, is stamped something like...10 73 This obviously indicates the hub was produced in October ( 10th month) 1973.

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These photographs are of a MK2 with hub date 73 '6 (June 1973)

In my experience, plenty of 1972 hubs had very faint date stamping... but most other years are easily noticeable. Because the centre rear hub is usually dirty with oily dirt, it usually doesn’t rust so badly that the letters become rusted away.
If you have a five speed Chopper, there is no rear hub date... but as the bikes were produced in 1973/4/5/6, they all have datable frame numbers to go from.

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