Brake question-swapping disc mag for drum mag

[Dieselchanic]

My '79 has a crusty disc brake rear mag but I've got a nice drum brake mag with a new tire off an '81. I want to swap the drum wheel in. Is the brake pedal setup the same for each wheel? Looking at it, it appears I can make it work just by reclocking the splined shaft inside the pedal. I don't know if that will work or if the leverage is the same? Obviously I'll have to make a brake rod but that's elementary. As far as spacers are concerned I can turn new ones on my lathe if it's not a direct swap in that regard. Any help is appreciated. Thoughts and arguments concerning the stupidity of giving up a disc in favor of a drum are best kept to yourself.

 

[weekendrider]

Because of the difference in light switch, brake stay arm etc. You may want to consider sourcing the complete swingarm and lever for the change over?
I haven't owned a disc'ed bike but do have the lever off of one if you want a picture of the two different styles.

 

[Dieselchanic]

Because of the difference in light switch, brake stay arm etc. You may want to consider sourcing the complete swingarm and lever for the change over?
I haven't owned a disc'ed bike but do have the lever off of one if you want a picture of the two different styles.

Yes a pic would be nice. The stay, switch etc doesn't worry me. I'm used to fabbing all this stuff from scratch on my other builds. Just wondering if I can use what I've got as far as controls or if I need to go to something like the JSC mids...

 

[weekendrider]

First the cam/lever pivot/thingamabob I have, was acquired in one of several boxes of excess XS650 parts from a dudes build so that said. I was told it was from an XS but never having a disc brake I am assuming. I don't mind being an ass but don't let me make one of you. Since you have one to compare you can decide if it is correct or not.
The one with the brake rod is from an 83. And they are more of a pain to remove with the swingarm on than I thunk. Course the rust probably wasn't helping.
I left the rod and return spring on for reference. The top hole is for the brake light switch spring. I took a couple of shots with it all connected if you want pics for reference at some point. Pardon the poor photography. Itsa bitch seeing the screen in sunlight(4 me).

 

[XSLeo]

The only thing from the disc brake set up that can be used on the drum brake set up is the pedal. Everything from there back is different.
On the swing arm you either replace with a drum S/A or weld a strut bracket on the bottom of the S/A. That's the only difference in the S/A's. The brake light switch mounting is different. The pedal height adjuster is different.
I did kinda the opposite on my 75. Converted from drum the disc. All these things apply on my swap as well as on yours. In my swap welding on mounts for the master cylinder was a bit tough, getting them located right was the thing.
I know you said to keep comments about how stupid this swap might be to ourselves but, I'd like to know why you want too?
Leo

 

[Dieselchanic]

Leo, simply because my disc wheel is really crusty. I could resurrect it but even the aluminum is pitted so it'd take a bit. If it's a huge job (and it looks as though it may be) I'll probably just clean up the wheel and swap the new tire on. I do like the look of the drum better and since I am running a disc up front the brakes are adequate for my riding style and needs.

Thanks everyone for the replies and especially the pics. That's exactly what I needed.

If all I had to do was reclocking the pedal and do a stay and rod I figured why not? It looks quite a bit more involving though