High-Mileage Classics: 200,000-mile 1973 Norton 850 Commando

Reader Contribution by Stan Keyes
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Stan Keyes has racked up more than 200,000 miles on this 1973
Norton 850 Commando since buying it new.

I have a 1973 Norton 850 Commando with over 200,000 miles on it. The bike was purchase new from Longs Cycle in Miami, Florida, in Nov. 1973. It was my only transportation for the next 10 years. Miami is probably one of the worst places in the south to own a motorcycle; the weather is great but there are no decent roads to ride on. There are five roads leaving Miami, all straight.

In the 1970s, neither the drivers nor the cops had any tolerance for motorcycles, and I was lucky to move to north Florida shortly after purchasing the Norton before I lost my license or my life. By November of 1974 the bike had 28,000 showing on the odometer. It turned 100,000 miles on the way back from the mountains in the summer of 1979. I pulled over and took pictures of the odometer with all nines and then all zeroes. An exit ramp crash trashed the original speedo in 1981 at 125,000 miles. The front wheel got trashed in the same wreck, and I was tired of trying to keep the spoke wheels straight so I adapted some Yamaha mags. The only problem with the mags was there was no way to run a speedo drive, so the new speedo sat at 0 miles for a few years. In 1985 I built a Commando to go vintage roadracing, so I went back to the spoke wheels so I could bring the street bike along for spare parts. Since my son started motocrossing the same year I started roadracing the Norton just didn’t get ridden near as much. The speedo is showing 60,000 miles now and the Norton has to share seat time with a couple other Nortons, Triumphs and BSAs.

The Norton has been a pretty reliable bike for 38 years, it just requires a little attention and a little zen from the owner. I installed an oil cooler the first year and change the oil every 1,500 miles; sometimes that was twice a month. The filter was changed every third time and the trans and primary oil every 3,000 miles. It burned an exhaust valve at 20,000 miles. I replaced the valve with a used one, and lapped the seats and installed new rings while I had it apart. It got new rings and valves at 45,000 and 75,000 miles. I took the bottom end apart at 105,000 miles just to check it out. The crank was still perfect and it went back together with just new rod bearings and seals. It still has the stock cast iron valve guides that have been knurled. The valve seats are still in good shape thanks to stainless steel valves and a little lead substitute. The transmission had the layshaft bearing go out, replaced by a roller conversion, the high gear bushings have worn out a couple of times and the kick pawls have been replaced three times. Some of the gears and bushings have been replaced as they show wear. The stock clutch 80,000 miles before it started slipping and dragging at the same time. The primary chain broke at about 150,000 miles. The original Reynolds drive chain lasted about 12,000 miles. The replacement chains lasted only about 8,000 miles each. I finally converted it to a 520 setup so I can use a good o-ring chain.

The rear tires last about 5,000 miles no matter what brand, and I am running 18-inch tires for better tire selection. The front tires last forever but get cupped after about 20,000 miles. The stock Amal concentrics were toast after about 15,000 miles. After wearing out the second set I put a set of Amal MKIIs on and they worked really well except the choke plungers had to be replaced about every 10,000 miles. They lasted 50,000 miles until they started running rich no matter what I did to them. I guess I work them out. I went with a single Mikuni and haven’t had any carb issues since. A Boyer ignition replaced the points setup after wearing out three spark advance units and lots of points and condensors in the first 50,000 miles. The Boyer seems to wear out a pickup plate every 20 to 25,000 miles but is reliable otherwise. The Smiths speedo drives wear out about every 20 to 25,000 miles so I have been through a bunch of them. The Chinese replacements aren’t any better, but are cheaper. The Norton was originally a Roadster but has been set up as a LongRange Fastback and is now an Interstate with the larger seat and tank. The Koni shocks have been on for about 15 years and still work great. I have found that the Daytona bend handlebars and Norvil rearsets are the most comfortable way to ride. The wooden stock brakes have been upgraded with a Magura master cylinder, stainless brake link, 12-inch Norvil floating disc and a Kawasaki ZX7 caliper. It actually stops now instead of just decreasing speed. Now that it stops, it does everything well and I see no need to replace it with a modern bike. I am 61 now and bought it when I was 23. I am sure I will ride it as along as I can still kick start it, and even longer if I have to adapt an electric start for it.

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