Think long and hard about what you ‘re going to do with the frame. It took a draw of thinking to make certain that my human body chop was going to work. In the end, it worked out OK.
mental picture 1 shows the frame of reference before chopping ( it ‘s top down on the bench )
The skeleton was chopped to that the bottom bracket shell was towards the front of the bicycle. We ‘ll be stretching the ensnare.
picture 2 shows the frame after the chop ! There ‘s no going back nowadays ! I decided I wanted to keep the match top tubes as they ‘re such a great have, so I cut them as near to the rear hub as possible.
photograph 3 : The following tone is to mock up the bicycle with the newly frame design. It ‘s authoritative to put the wheels on so you can get the height chastise. For this mock up, I supported the bottom bracket and extended the ensnare with some thin trash tubes. I noticed that the duplicate top tubes were excessively depleted thus I took a luck and bent them by hand to the correct altitude for the seat. If I damaged them ( split the joint, etc ), I would have had to weld them to repair them. As it was, I got aside with it.
I was happy with the overall form and design of the new frame, so the next footfall was to extend the skeleton by inserting two new steel tubes from the bottom bracket plate to the bottom copulate of tubes at the bottom of the seat post.
For this undertaking, I used the measurements from the mock up to cut two lengths of metro. I used a pipe carouse to make a flimsy fold near the penetrate bracket shell. This was necessity as the down tube fish had changed. painting 4 shows this clearly.
At this degree, the seat tube is not attached to anything – it ‘s just floating.
The future gradation is to secure the bottom of the seat tube.
picture 5. Using a piece of cardboard as a template, I made a plate of sheet steel which I positioned underneath the seat pipe. I welded the denture on top of the horizontal tube. This strengthens the joint between the two newfangled tubes and the buttocks tube. I then welded the buttocks tube to the plate.
Next, let ‘s turn our attention to the acme pipe. Again, these are barely floating – they ‘re not attached to anything yet.
mental picture 6. Again, I made another plate from sheet steel. You ca n’t see it, but I used the lean bomber to make a slot in the seat metro. I inserted the sword denture into the slot, then tack welded the plate to the buttocks tube. This slot means the joint will be a lot stronger and there will be less down stress on the dyer’s rocket. future, I welded the two top tubes to the steel plate.