I can't understand a lot of Norton's over in the USA 50 years old and have so little miles on the clock, is it because of all the winter months of not riding, or owner scared to ride them with fear of them breaking down or they been ridden so hard in such short time that something major has happened to them or they haven't been maintained that they wore out on such low miles, who knows.
I brought my 74 Commando new being young (17 years old) I flogged the sh it out of it for the first 4 years then I Pulled it all down for the Featherbed conversion the bores were worn oval from the flogging I gave it so a rebore was part of the Featherbed rebuild and other work that was done to my motor for smooth running with hard mounted motor as well a balanced crank for the Featherbed, started the conversion in 1980 and was back on the road 2 1/2 years later, I was unemployed at the time so money was a bit tight then before starting work at the Tec College at the start of 82, where I had the machines and tool to finish off the conversion.
At the time I had went with 40 oversize Hepolite pistons and the rebore and final hone was very min with less clearance than what Hepolite recommended, I ran it in the first 100 mile on a very cold winter night, to this day I am still running those same pistons and my motor still feels tight, they were re ringed just over 15 years ago when I replace the crank case from a few hairline cracks around the main seal area (thinnest part of the motor) and that rebore and pistons have well over 130k miles on and yet my motor is still very reliable, before the rebore and flogging I gave that motor when I was young and silly had about 30k miles and the original bore was worn oval from all the burnouts I done.
One thing that has worked for me since 1982 when I put the Norton back on the road in the Featherbed frame I been mixing STP with my oil changes even right up today and I think that is one major reasons my motor is still running good and even when I replaced the crank the bores were still good as well the pistons, only gave it a light hone when I put the new rings in, that was 15 years ago.
So what I am saying you keep up the maintenance, run good oil and Commando motors are very reliable and will get long life/miles out of them, my Norton was a every day rider till 2013, I still rode it hard but I didn't flog it like I did when I was young and silly, I am still running the same 2S cam profile on my original cam that was built up and reground back in 82, am still running my original valves that came from the factory but the guides been replace 3 x, first time from a stuff up by a so call head expert, but the head has been ported for my cam and exhaust I run very open mufflers with a bit of back pressure.
I just can't understand why so many have done full rebuilds with so little miles on them or let them sit for 30+ years without been run, Commando motors are so simple and are easy to do work on them as well keeping them maintained, all my British bikes have always been ridden and ridden hard but not flogged, I have owned 2 older Triumphs and 2 modern Triumph Thruxtons and all had lots of miles clocked up on them, my life has always been on bikes since I was 15 years old and the Norton is now 50 years in my ownership and is still going stronger than when I first brought it new in 1976, but has a lot more torque than it did from stock, and I just did simple mods to the motor to make it go better without throwing too much money into it, but the things were cheap to do back in the 80s, but love to build a motor with Jims bits inside it, if only I could afford it all.
Ashley