If you go through the various Yamaha XV-related forums, FBook-groups, etc. you will see the same five or six models of rear shocks being recommended. Very few people actually dare to try out something completely different or even worse: something new.
Well, I happened to more or less fall over a 2018 KTM Duke 790 shock, which had done less than 10,000kms from new. In KTM circles this shock is not quite regarded to be quite the cream of the cake, but this also meant it would be rather cheap. Also, what are the odds for it to be worse than a shock from a mid 1980ies dirtbike?
The shock measures 390mm from eye to eye, which is 25mm longer than a TR1 stock rear shock, but exactly the same length as my previous XT600 Tenere rear shock and it's got another trick up its sleeve: both mounting bushes are of 12mm inner diameter, making it a straight fit.
Now if you were a cheeky bastard, you could ignore the fact that the swingarm has got a 45mm cutout...
... yet the shock is only 24mm wide.
And quite frankly, aside from the lower shock pin being sprayed with water and a rather theoretical chance of the shock twisting a bit and thus getting bent over the years, I'd say totally doable.
But we're not after doing a fix in some emergency situation. So two spacers approx. 25mm OD, 12mm ID and 10mm wide where quickly made on the lathe from some leftover ally scrap.
Et voilá: Rear shock properly located inside the swingarm.
At the same time, I had one of those: You really know you had a bike for a while, when you have to replace the horns, because they have stopped working due to bad weather motorcycling, i.e. at least partially rusted to buggery.
Verdict after the first test-ride? Well, suspension technology made some notable leaps forward in the last thirty years. It's a bit stiffer than the old XT shock and it should be brilliant when riding two-up. That being said, I may actually end up reducing the pre-load a notch or two. Shame the 890 has got an external reservoir, which makes it impossible to fit into the TR1 frame.