My observations are limited to the American market.

The only Triumph models I know anything about are the air cooled parallel twins. The move to Thai production seems to have occurred in 2005/2006. I have not seen any 2005 or earlier T serial numbers. 2006 is a mixed bag with either J or T serials... possibly an indicator of early or late in that year's production. 2007 on out have T serial numbers.

As pointed out earlier, at the moment all Thunderglides are assembled at Hinckley.

I do not know if you can special order a J serialed bike or not.


Edit:

From the British Chamber of Commerce

Quote:

Triumph's first factory in Thailand was opened in May 2002 and was established for the manufacture of motorcycle components including Frames, Fuel Tanks, Header Systems, Swinging Arms, Engine Covers and Chrome Plated Parts. A second factory was opened in 2006 where a wet painting facility and assembly line have been established. A third factory, opened in 2007 includes high pressure diecasting and machining. The company now employs approximately 800 staff in Thailand.



2018 FLHCS 2014 Surly Straggler - 16,000 miles and counting!