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08-12-07, 07:06 PM
First off let me say, I'm not a hardcore bicyclist. Just recently I sold my bike, and came into a bit of disposable income, and since 2 roommates left and were replaced with roadbike riders, my curiosity got peaked and I began thinking of how I can make my own frame, with their help for the specs, and maybe make a few frames for my friends.
I build longboards right now, so the concept of building my own things to ride isn't new. Plus, after making a few composite boards, I know how to use carbon and fiberglass. I am good at mig welding, and alright at tig, so I figured welding together a frame wouldn't be hard, but the jig is what had me stumped! Being an engineer though, I drew up this little cheap design, and wanted some feedback before I actually went and built it.
I designed it so the bike would be upright so I can do some composite work after I get a basic steel frame under my belt. Plus I tried to design it so I could move things back and worth, adjusting the wheel base, angles, ect ect.
See the picture attached for a picture of the bare bones idea of my plan. The basic idea is this:
Get a 4X8 sheet of plywood, Some 2X4 wood to be cut, 2 2X4X8, as well as some angle iron and metal pipes.
the 2 2X4X8 will be mounted 4 inches apart, down the center of the board. This will insure everything else is mounted in a straight line. Then, the parts that hold the bottom bracket shell as well as rear axle can be screwed down to the plywood in the 4 inch gap and held steady.
Bottom bracket shell is tack welded to a steel post the hold it at the right height.
The head bolt had me stumped, as I wanted it so it could change angles for different rakes, so here is my idea:
Head bolt will just be held by a long pipe, and a clamp to hold it at the correct height. From there, the pipe is welded to a another perpendicular at one end, and THAT pipe is clamped to another pipe screwed to the plywood plank. See the drawing lol.
Rear axle is the simplist, with an axel held by a piece of wood attached to a piece of 2X4, and that placed in the groove.
And that should be it. The seat pole can be pre welded to the bottom bracket shell so the shell can just be tacked at a different angle, adjusting the seat pole angle. That, plus bikecad, levels, protractors and stuff, and some trial and error should do it, right?
Any immediate problems with this? I'm not trying to open a business but I love building my own stuff.
I build longboards right now, so the concept of building my own things to ride isn't new. Plus, after making a few composite boards, I know how to use carbon and fiberglass. I am good at mig welding, and alright at tig, so I figured welding together a frame wouldn't be hard, but the jig is what had me stumped! Being an engineer though, I drew up this little cheap design, and wanted some feedback before I actually went and built it.
I designed it so the bike would be upright so I can do some composite work after I get a basic steel frame under my belt. Plus I tried to design it so I could move things back and worth, adjusting the wheel base, angles, ect ect.
See the picture attached for a picture of the bare bones idea of my plan. The basic idea is this:
Get a 4X8 sheet of plywood, Some 2X4 wood to be cut, 2 2X4X8, as well as some angle iron and metal pipes.
the 2 2X4X8 will be mounted 4 inches apart, down the center of the board. This will insure everything else is mounted in a straight line. Then, the parts that hold the bottom bracket shell as well as rear axle can be screwed down to the plywood in the 4 inch gap and held steady.
Bottom bracket shell is tack welded to a steel post the hold it at the right height.
The head bolt had me stumped, as I wanted it so it could change angles for different rakes, so here is my idea:
Head bolt will just be held by a long pipe, and a clamp to hold it at the correct height. From there, the pipe is welded to a another perpendicular at one end, and THAT pipe is clamped to another pipe screwed to the plywood plank. See the drawing lol.
Rear axle is the simplist, with an axel held by a piece of wood attached to a piece of 2X4, and that placed in the groove.
And that should be it. The seat pole can be pre welded to the bottom bracket shell so the shell can just be tacked at a different angle, adjusting the seat pole angle. That, plus bikecad, levels, protractors and stuff, and some trial and error should do it, right?
Any immediate problems with this? I'm not trying to open a business but I love building my own stuff.