It's not that difficult to replace the Norton 2-piece axle with a one-piece. I did it several years ago, replacing it with the axle from a Honda CB 350 (which, surprisingly, has a much beefier axle than a Commando). This was originally an e-mail to Steve Shiver (hobot) who said he was posting it on a Norton forum, so if this is the forum he was talking about, it should already be here someplace. This has also been discussed extensively on the Internet group for the International Norton Owners Association (
INOALIST@yahoogroups.com) which some people here may also belong to.
From: "Taglieri, Michael"
To: <hobot@madisoncounty.net>
Cc: <miket_nyc@verizon.net>
Subject: RE: One Piece Commando axle modification
Date: Tuesday, May 03, 2011 7:16 PM
Here is basically how it's done. You need is a metal-turning lathe with a 3-jaw chuck but it doesn't have to be a particularly good one. (A high-precision drill press would also work if you know how to use it, but centering the parts on the table would be a real pain). You basically put each part in the 3-jaw chuck and drill it out to 17mm. On a small lathe like my 7x10 I'm not actually sure I ever DID a detailed post, but just a general e-mail. The only way to fully explain it would be a full-fledged article illustrated with pictures. I'd like to do one but I have to find the time, and also find another Commando with its rear end apart for the "before" pictures.minilathe, this requires step-drilling (starting with a small drill and gradually increasing the size) because 17mm is a big-ass drill). On some parts, the enlargement is hardly noticeable, and on others (like the dummy axle) most of the part gets taken away, and it turns it into a spacer. You don't have to drill the actual bearings, because Norton used 17mm bearings in the stock rear axle and sleeved them down to the axle size.
My rear axle is from a Honda CB 350, but Ben English said many bikes of that era used 17mm rear axles. After you get the axle, you file the slots in the swingarm larger with a large file. This is easier than it sounds, because you make a test-bar on the lathe -- a rod a few inches long with steps in it, starting smaller than 17mm and working up to it. This is not high-precision work, because you WANT a little play so the axle will go in easier. Then you have to make spacers for both ends of the axle that the adjusting screws can ride against. Again, this is an easy job with a metal-turning lathe.
The only part of the job that's not easy is modifying the speedo drive. The hole in the middle of the steel "top hat" spacer in the stock speedo drive is 9/16" to fit the stock axle, and the spacer then fits into a larger hole on the speedo drive. You can't drill out the spacer to 17mm because there isn't enough of it. Instead, you have to make a bigger one that's 17mm on the inside, then bore the body of the speedo drive to accept its outside diameter (which can be anything you want, within reason). This is the trickiest part of the job, but it would still be easy for a hobby machinist with a lathe because only the 17mm inside hole is a critical size, and that only has to be drilled 17mm, not bored or reamed.
