collision666

I was just wondering the possibilities of building my own frame over the summer. My buddy is a professional auto mechanic, hotrods and the such, and has a fully equiped shop. In theorey this seems like a possibility but in reality is it? Thanks for any input.
Dave

Tom Stormcrowe

You'll need a framing table, jigs and good welding/brazing/metalworking skills, but it's doable!

collision666

My friend has the framing table for building motorcycles. I assume that I would be using the same one. I personaly have little metalworking skils but he sure does. I am looking for a project where I could learn about metalwork without having to spent a fortune on a Hotrod or motorcycle. I bike frame seems like something that would be in a reasonable budget unlike the other two.

bellweatherman

Can you get a picture of the framing table your friend uses for motorcycles? It might be helpful for others to see. Plus, the pros on here might be able to tell you if it usable for your bicycle framebuilding project.

collision666

I am currently finishing up my semester in Philadelphia and my friend is in upstate New York. I am not going to be going up there until a little later in the summer so I do not have the chance to currently post a picture. I was trying to figure out if this is a project that I should be considering to save my money for, and about how much is would be for a nice steel road frame. I just recently bought a new (used) Lemond so I don't really want to spend whole lot on it.

collision666

Is there a company that makes prefabbed rear stays and bottom bracket housings? That seems like the toughest parts to get right.

bellweatherman

Hmmm. I don't think so. You might be able to contact a framebuilder to see if he'd build a rear triangle for you, but then you're missing out on the fun of doing it yourself. Most builders build the front triangle first (including the bottom bracket shell) before they build the rear triangle. Though IF bikes likes to weld the bottom bracket shell to the chainstays before moving on to building the main triangle. Have you tried looking on frameforum.net? It's got a lot of good info there too.

collision666

I have done a little research and I think I'll be using lugs. That seems like the best way for a beginer to start. I had not been on frameforum.net. Thanks for the link.

Francis Buxton

Read a bunch on Frameforum.

You can get pre-bent chainstays and seatstays from Henry James or Kirk Pacenti, or Nova Cycles. Or you can use straight stays. Those guys also sell bb shells, lugs, tubing, complete bike tubing kits and all the little braze-ons you'll ever need.

collision666

Thanks for the advice. Hopeful I'll be able to start the process in the middle of the month. I'll update the progress, as soon as there is progress

NoReg

you can use a motorcycle jig, in case anyone is interested. I mean you will have to fab specific fictures to attach the smaller drop-out/axel plates, the neck, and the BB. I am doing my frame project on a motorcycle jig. The best way to use the jig is to set it up so the neck is vertical. There are bike specific jigs that work this way, and it simplefies controling the seat tube. There isn't anything controling the seat tube as you can see if the drawing loads, but there are any number of ways of dealing with that.

bellweatherman

The knock on those type of motorcycle jigs is that accuracy pales in comparison to plate-type jigs. Advantages of an old-school motorcycle jig are ease of adjustability and super access to joints for tack welding/brazing. The big downside is not-so-good tolerances on accuracy.

It is VERY hard to make a bottom-up jib like that and retain the accuracy of a plate-type jig. Simple reason is that a plate-type jig references the measurements from one point of reference, the plate itself. A bottom-up motorcycle jig references the measurements off of the accuracy of the interface between the base part of the jig and the upright arms of the jig. Note that also, there is no way to make sure that the seat tube is accurately centered.

NoReg

I hear you, but somehow this stuff doesn't come up if someone mentions jigless building or using the aluminum frame jig. My jig weights pretty close to 200 pounds 100 of which is in the table part which is surfaced with accurate 1/2" plates. I do agree that the objective of using the jig as both a measuring and a positioning instrument is something one would have to approach with care. But when it is locked down, it ain't moving, so worst case one might have to check a few measurements, but once they are on, I'm not worried. This thing is so much stronger and more rigid than the aluminum frame jig, if the issue of positioning the seat tube becomes real, I will adress it at that time with plenty to tie into. I thought it might be interesting to see how it worked to weld the seat tube to the BB first and use the bottom fixture and the tube itself as a support for the other tubes. But... if that doesn't work, and it sounds a little iffy, I can easily attach some other fixtures.

On the other hand I don't necesarilly suggest one build this kind of jig in preference to a bike jig, unless one had reasons for finding it useful as either a motorcycle jig or for other stuff. In fact if I had really built it the way I wanted it, it would have been the bed for my wood lathe, but that will have to wait.

I don't know why people assume motorcycles can aford to be built with less accuracy than bicycles, must be something to do with synergy from ridding at 120 mph with a 150 hp motor between one's legs that just makes the whole accuracy thing optional. :0)