Rob sorry 1023-19 is front and 1024-40 is rear.
I never take umbridge

Riders will always use a product they have faith in whether it is leathers, oil or even chain.
I just find the hype concerning 520 goes a little over the top. Yes racers use 520 but then change them very very regularly, like most races. Yes it is lighter comparing like for like Jap non O ring or O ring. I have many friends with modern high powered machines such as Fireblades than go throuhg 520 rapidly indeed many bike manufacturers now go to 525 which again is halfway house between 520 and 530. The same applies to 525 in as much as it seriously limits choice.
On the forum I just give advice what peeps do with it is up to them. I caused a stir when I first muted the idea of the Merc duplex to replace the triplx but now it is widely used and not just on Laverdas.
As for alloy sprockets the same applies.....racers change the gearing more often than I change my boxers and given the lightness plus the lack of miles it is not a bad choice but for road and touring most find the wear too much. We have to go back to basics in as much as 2 sprockets and a chain is a gearbox. For best wear and running all should be changed as a set. You would never replace one intermeshing gear in a normal gearbox.
In reality you will get 2-3 chains to a set of sprockets but each will wear at a faster rate.
I have always put comments on here with a bit of tongue in cheek and dont care if people agree or disagree, I just love not only the forum but also the bikes (Laverdas), the people that I have met and above all greatly admire the knowledge shown. Hopefully soon I will have a Laverda so I will be able to put my money where my mouth is and yes I will run standard iwis non O ring just like my hooligan Bandit 1200.
Lub I aint upset and its the crack that makes it good.
Still love you all
Andy