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Does cut angle matter (odd take-apart joint)

I am going to cut a bicycle frame in two.

The frame has a spar main section of a taller-vertically rectangle with half-rounds on the top and bottom; this is place for the cut. I'll make a matching inner sleeve for both alignment and tightening.

There is a vertically-coplanar tube joining this spar at an angle of about 20 degrees. I will run a rod though this tube and it will cross the joint into the sleeve holding a captive nut.

Does the angle of the cut matter - 90 to the spar, 90 to the rod, half- way between?

I have a bit of latitude with lateral placement of the cut, so I could arrange for the rod to cross the joint other than centred. The weight would tend to open the bottom of the joint first, would a lower crossing be better?

Reply to
xpzzzz
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Your description isn't clear enough for me to tell what you mean or what you want to do. Is the "spar main section" a part of the top tube, or a part of the down tube? (See terminology at .) What is the name of the "vertically-coplanar tube"? Is it the seat tube, head tube, or some other thing?

Is your goal to cut the bike in half for easier transport and add connecting rods that allow reassembly so the bike can still be used? How much weight will the joint have to carry, and what are the height and width of the spar section?

Reply to
James Waldby

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Cut is to be in the main tube somewhat forward of the place where the (nearly) horizontal joins; I have removed the rack section rearward of the three-tube junction, and the rod will start there and run forward through the (nearly horizontal) tube towards the cut.

Reply to
xpzzzz

It looks like cutting perpendicular to the axis of the big tube is the easiest thing to do, and if you use a coupler like the one shown in probably is what you would have to do. However, it probably would make sense to get oval tubes from junk bikes, make up several junctions with cuts at different angles, then stress them (with known weights) until they break.

Reply to
James Waldby

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