rear axle diameter and swing arm slot width

As I said in another thread I am adapting a commando to use cast wheels. I've looked at all the places where norton parts transition into the non-norton wheels. I don't want to do anything to alter the norton parts, so the modification is reversible by just swapping the new parts back to the old ones,... so....

I'm making the transition at both wheels by keeping the norton axles. I'm keeping the norton axle in the front wheel and just ordering new bearings for the cast hub which have the ID of the norton axle instead of the donor bike axle which is a different diameter. I've also ordered some spacers to fit the norton front axle, which btw is metric. 17mm, What is with that? how come it's not some american/british dimension??

... But the real mind bender to me is the rear axle, which for my bike appears to be 9/16ths diameter. (1970 model) So I have an issue with finding bearings that have an english ID and a metric OD for the various recesses in the metric rear wheel.

Reasearch here has told me that my options are to open the slots in the swingarm to accept a 17mm axle. I plan to buy one of madass's one piece axles which I assume are 17mm diameter. or maybe 9/16ths? and 17mm? I'm not sure yet, but I know that my swingarm slots are too narrow for a 17mm axle right now.

Am I missing a simpler obvious alternative?? thanks..

the rear 9/16" axle uses the same 17mm ID bearings at the front, the difference is the rear bearings are supported by a central axle spacer which is 9/16" ID and 1" OD but stepped down at both ends for the 17mm bearings, so you should be able to use the standard type set up in your cast wheels,
Although of interest there are bearings available which have a metric OD and an Imperial ID, I've purchased a few,
Don

Except the stepped down spacers in my current spoked hub will be unique to that hub, and each brand of wheel hub may need different length stepped down spacers depending on the distance between the bearings in each hub assembly. So, even though I have a stepped down spacer in my current (no cush) hub, I would still have to fabricate stepped down spacers for the new distances in the cast hub... or am I not understanding you?

Ya know what.... couldn't I get a single length of tube in 9/16" ID and 17mm OD in the exact width of the swingarm and run a 9/16th axle right through it, so it would support all the bearings and support all the spacers that the hub currently has? Do you think that would work?? No stepped down spacers needed... I'll probably have to have that length of tube made by a machinist I know because I don't think I'll be able to buy that anywhere,

.... but I will need a one piece axle...


As far as I can see, I have 3 choices:

1) I buy a one piece axle and a single sleeve of 9/16" ID x 17mm OD x 8 1/16" length

2) I have to buy all new bearings in 9/16 ID x various OD, and buy, or have made, all new unstepped spacers in their required lengths

3) I widen the swingarm slots and go with the yamaha 17mm solid axle I currently have.

"Except the stepped down spacers in my current spoked hub will be unique to that hub, and each brand of wheel hub may need different length stepped down spacers depending on the distance between the bearings in each hub assembly. So, even though I have a stepped down spacer in my current (no cush) hub, I would still have to fabricate stepped down spacers for the new distances in the cast hub"
thats correct, you will need a new bearing distance spacer the correct length for whatever hub you use. then other shorter spacers will be required and made as needed.
your idea of making one long 9/16" spacer is not really an option, that idea wont work and it would be very hard to make a spacer that long with a nice fitting 9/16" bore.

I filed the swing arm slots to fit the Yamaha axle. It would be fairly simple to make a spacer if needed to go back to a stock wheel.

yeah, right now I am considering buying a second swingarm and modifying the axle slots to use the complete yamaha rear wheel and axle, which is complete, intact, and functional. A second swingarm means I will always have a complete bolt on/bolt off option to return the bike to stock if I reach a point where I'm,...... screwed... during my modifying.

I just ordered the swingarm which I am going to weld a stand off for the drum brake arm to be mounted to, and a shackle to hold brake cable. I also ordered a sprocket in 42 teeth so my ratio will not change, nor will I need a new chain or to change my front sprocket...

Thanks to everyone who contributed here. It really helps to see other people's solutions to chose my own ...

... just like up front I originally was going to use the yamah axle and bushings, but since I couldn't use the speedo drive because it threw the wheel way off center, I am now using the norton axle and swapping out the yamaha wheel bearings to suit the norton axle. Sometimes a change of plan is better than a long complicated solution.