This is an account of a bike we are building from accumulated stuff. All the bits and pieces are stuff we had lying around either because of some disaster or another, or because it was acquired as part of a deal. We'd done some basic planning before I thought to write it up so the first couple of stages weren't photographed.

First thing was to get all the parts we planned on using in the same place. This needs to be the forks, wheels, tyres, and motor at a bare minimum. First thing we do is always place the motor on a block of wood which gives us the ground clearance and chock it so that it sits level(ish). Do that and you've got your first dimension, easy isn't it? After that we get a ratchet strap and hook it round the front wheel rim and the lower tree (or yoke) of the assembled forks and tighten the strap up until the forks are compressed by one inch. This does two things, firstly it simulates the ride height of the finished bike, and secondly it stops the forks from rolling around!

At this point we get a pair of jack stands (axle stands in England). Now the ones we have are quite big and reach to a good height, but I suspect that the average set won't reach high enough for the next bit, so visit your local muffler or exhaust dealer and grab a piece of rusty exhaust pipe out of the skip to make a loner top for one of the stands. Basically you're going to position this in front of the motor to get the "look" you want.

Next thing to do is to stuff the axle (spindle) through the rear wheel and position that behind the motor using the other jack stand to prop it upright. So now you've got the wheels and forks positioned relative to the motor, and if you stand back and squint at it a little you should get a good idea of what the bike is going to look like. Fiddle with the "rake" by raising and lowering the front stand, slide things backwards and forwards in relation to the motor until you're happy with the way it looks.

Now's a good time for reality to impinge on your styling, before youve actually cut up any tube or expended to much energy. Use a broom stick or similar to see whether your layout is going to clear the carbs and help visualise the actual rails of the frame that'll hold the bits in the relationship you've established. Moving things by a 1/2" or so at this point can save you a lot of trouble later on.

When you're happy with everything, it's time to get the tape measure and degree finder out. You need the following dimensions.

That's it. Just six measurements. You'll need to measure some other stuff to get the width of the axle plates and the offset of the chain form the centerline but those six basic dimensions will give you the "look" you want for your frame. As for the chain offset there are a couple of things to remember. Firstly if you use the stock wheel the width between the axle plates is going to be the same as the width of the end of the stock swing arm, BUT that width isn't always symetrical about the centerline quite often a jap frame is as much as 20mm "wider" on the drive side than it is on the other side. Measuring offset isn't something I've written up or got any pictures of as yet so we'll neatly skip over that for now and move on to actually setting things up and I'll try and remember to write a seperate article on establishing the chain line later.