Easy frame swap

YammieBruh

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Hey all. So I've managed to get myself into a bind. I've got a 78 special with some apparent frame damage. My question is will a 79 xs-2f frame work with no fabrication work required. The 78 is disk brake but the 79 was drum. I'm hoping everything is a straight swap
 
You'll need to swap the swingarms... the brake stay mounts are different. The brake pedal spring and switch mounts are also slightly different, as are the mounts for the master cylinder (one frame has 'em, one don't). Your best be would be to go with the brake system the new frame was built for.... no mods would be required then. And if I'm not mistaken, the sidecover mounts are also slightly different
 
No, it is not a straight swap. The 78 frame has provisions for a hydraulic master cylinder. Also, the brake switch tab is different. I'm not sure about the position of the brake lever mount. I have both here and I can get you pictures later.
 
The brake lever pivot is also different between the drum and disk setup.
 
So, there more to it than replacing the lever?

Levers are the same. One pivot has tab for the rod to push straight up into the master cylinder, the other pushes (pulls) the brake rod straight back to the drum.... different angles on the tabbing.
 
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Levers are the same. One pivot has tab for the rod to push straight up into the master cylinder, the other pushes (pulls) the brake rod straight back to the drum.... different angles on the tabbing.
My only concern is the bore through the frame for the brake lever. Are they the same size and in the same place?

If I can't easily swap my frame, then @YammieBruh can drive the 14 hours to Mississippi and get my frame. I haven't looked into my title situation.
 
My only concern is the bore through the frame for the brake lever. Are they the same size and in the same place?
Far as I know... yes. I sent a forum member the stuff to convert from drum to disc. He never mentioned a problem with the pivot not fitting.
 
Far as I know... yes. I sent a forum member the stuff to convert from drum to disc. He never mentioned a problem with the pivot not fitting.
I'm going the opposite direction. Disc to drum. I expect only the switch tab has to be changed.
 
Just looked at a drum brake frame Marty and there's no adjustable stop tab there. So it looks like all you'll need to do is cut off the one that's there for the disc setup.
 
E2CD94A2-D429-436E-BEBE-3436B542A4CA.jpeg

This is the drum brake Special II. The brake light switch has a tab just fwd of the passenger footrest.

5BF4E472-C5F7-4040-8A83-34A451DE831E.jpeg

This is the disc brake Special. The brake light switch tab is above the swingarm pivot.

To go to drum on a disc brake frame, only the brake switch tab has to be swapped.
To go to disc on a drum brake frame, the lugs for the master cylinder and brake light switch need to be addressed.
For either, the correct swingarm is needed, as well as the brake lever.
Other than odds ‘n ends, I think that covers it, correct?
 
To go to disc on a drum brake frame, the lugs for the master cylinder and brake light switch need to be addressed.
My disc brake frame has an adjustable "up-stop" tab that uses a screw and nut to adjust the height of the brake pedal when it's released. My drum brake frame does not. I find that kinda odd... you'd think both would have it. Anyone with a drum frame wanna have a look and chime in?
 
Hey all. So I've managed to get myself into a bind. I've got a 78 special with some apparent frame damage. My question is will a 79 xs-2f frame work with no fabrication work required. The 78 is disk brake but the 79 was drum. I'm hoping everything is a straight swap

http://www.xs650.com/threads/rear-brake-conversion-drum-to-disk-or-disk-to-drum.51944/
This is a swap from Disk to Drum or vise versa..........Some tabs will be different, it is a matter of swapping the parts over then check for any differences with some tabs that can be removed from one frame and added to the other.......make sure your measurements are spot on
 
Ok. since I've already got the parts for a disk brake set up I think it might be easier to go that route. If not then I need a new wheel, brake assembly and swing arm along with a bunch of other odds and ends. If I come home with even more parts the wife will have me sleeping on the couch permanently. It might take a little fab work to put the mc and brake switch on but it seems like a cheaper option at this point.
@jetmechmarty maybe if the border ever opens up.
 
Yes, there is a brake pedal height adjustment bolt and tab on the drum set-up .....

CJBU0rg.jpg
 
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