Ray, I had problems with the original rear shock on my 1996 Thunderbird and there are NO sources for rebuild parts here in the USA. Aftermarket units cost at minimum $500+ US dollars, up to $1200 or more. I found a lot of talk on Triumph enthusiast sites about swapping to various Kawasaki units, (see conversation about this below). After much experimentation, I am very happy with the 1994 thru 1997 Kaw ZX9 rear shock, the one with the remote reservoir on a hose. Cost $45 used off Ebay. Some, but not all parts are available; nitrogen bladder, some of the seals, etc., from RaceTech, USA. Most likely needed parts, (if any), are usually the bladder and the dust seal. Cost; bladder is about $20. Dirt bike shop refilled nitrogen for $20. The overall length is close to Triumph. "Dog bone" links to adjust rear ride height are popular with drag racers and can be found used for $20 or so. The original Kaw bracket can even be used on the Thunderbird. Setting "sag" is key to set-up and some experimentation with sag, rebound and compression settings will need to done, but it worked for me and I'm very pleased with the results so far. I may go with a different rear spring, but otherwise all is good for about $100 investment