7/3/13

XS650 Special rear disc to drum conversion

On the '79 Special I'm swapping from the 16" cast disc brake wheel to an 18" spoke drum brake wheel.
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Here are the parts I'm using for the swap, a brake pivot and rod from a '78 XS650, brake stay from an '83 XS650, and a right side drum brake wheel spacer from a '73 TX750 (same spacer as a drum brake XS650). The left side wheel spacer and brake pedal are the same from disc to drum.
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Rather than buying a drum brake swingarm I'm just modifying mine. The two brake line mount tabs and the hook are removed. The brake stay anchor gets cut off and welded in place on the bottom of the swingarm.
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Here is the swingarm after moving the anchor.
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For reference this is the brake pivot on my '75 which has the return spring mount and brake switch on the passenger peg mount.
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This is the drum brake pivot in the '79. Three issues here: the return spring mount is on the bottom frame cross-member, the brake switch is above the swingarm pivot, and the stop bolt bracket is in the wrong place.
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The brake switch tab is mounted right off the pivot area on the disc brake part (the top one). Rather than moving the brake switch, I'm just welding the tab to the drum brake pivot.
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Both pivots have an index mark at the 12 o'clock position, and this is a good reference point to use to place the tab correctly.
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The tab moved to the drum brake pivot.
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I then cut off and moved the return spring mount and stop bolt bracket.
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Here it is mocked up, and everything fitting as it should. I just need to do some cleaning and paint, and decide what tires to order.
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1 comment:

Unknown said...

Thank you. Some good pointers.