CUSTOM BASIC TECHNIQUE

What we are going to do is to go through the steps and procedures necessary to build a rigid frame. There are a couple of reasons we’ll discuss rigids for this; it’s arguably the most simple of frames to write about building, and it’s a good frame to start with for a novice frame builder. For example, there is no need to take into account rear suspension set ups and geometry, and we also need to be talking in a pretty general way fora rigid frame fits the bill quite nicely, so let’s run with that. This is the beginning and the basics of frame building apply to all types of frames, so we’ll keep the complications to a minimum to start.

What do we need in our shops to attempt building a frame? We’ll make a couple of lists, (you knew I was going to say that) and we’ll start with the personal skills that will be useful/needed. Bare in mind that if you don’t have some or all of the skills I’m about to list that you either need a very fat wallet, or a buddy/buddies that you can coerce/bribe/blackmail into helping you out.

Skills 
1.  Basic metalwork skills
By this I mean the ability to use a hacksaw (and cut straight) and a file (and file flat). basic metalwork skills include the ability to use a drill press and a hand held drill and center punch accurately on the tube (I suggest you practice on that as it isn’t as easy as it looks). Lastly, you need the ability to use an angle grinder and the various discs available including wire brushes.

2.  Welding skills
Go back to our Setting Up Your Home Garage articles. TIG welding skills are outstanding and current state of the art in the bike building world. But MIG is perfectly good enough for frame building.

As is our way  and everywhere in the custom motorcycle industry, we are constantly looking for a new angle on this and a new angle on that in the name of individuality, and as the frames seemed to have been pushed to the limit, next area of attention was the engine and drivetrain, and before we knew it there were seriously tuned diggers; turbo charged, super charged, and even multi-engined versions appeared.

In fairness many of the bigger builders only built these things as show boats and they were trailered to shows. A lot of them didn’t even have internals in the engines but a lot of average Joes looked at these creations and copied them. Sadly they were deathtraps and a lot of nastiness on the roads ensued! Thankfully things calmed down and the digger style died with disco. In that time lessons had been learned and the builders figured that using thin wall, skinny tube for any great length wasn’t the way to go. None of us had multi-million dollar Research & Development plants that we could try our our ideas on and perfect a tube size for a given frame application, so we played it safe and upped the diameter and wall thickness. After all, it seems most engineers will tell you that the fastest way of fixing most problems is to throw more steel at it (take a closer look at any Mercedes or Porsches)!

So what are we gonna do? I figure that we’ll take the middle road and use 1″ 12 gauge CFS 3 or DOM seamless and go through the steps of building a Triumph/XS style chopper frame. 10 gauge equates to more or less 3.2mm or 1/8″ , and 12 gauge is slightly less than that. You can ballpark these thicknesses as pretty much 1/8″ or 3mm.