Jigs and Frames

Some choices need to be made - does your dream bike need a custom frame? or can you use the standard frame or do you have to/ could you modify it? Help is at hand either way. You can if you want spend a small fortune and buy a frame ready built (Links to frame builders) or you could build a frame from scratch, The third option is to modify the frame that came with your chosen bike. The third option will probably be the cheapest, but you will have work to do your self or you will have to find some one to carry this work out for you. If you do not know how to weld or you think your welding is not up to scratch, have it checked by a professional. The last thing you want is the bike to fall apart, especially at speed!.

If you are building your frame from scratch or modifying your existing frame you will need a jig to hold the frame and help to make sure it is all straight and true. You can get free Jig plans from   www.crimescenechoppers.com , they are engineering drawings so you can take them to a fabrication shop to have the parts made. Another site I found was www.mechwerks.com who also have plans to build jigs although you have to pay for these on there site their are pictures of there actual jig for you to look at.

Once your jig is made you will now be looking for more information on how to use your jig or how to build your frame. There is a good video on the market from an American guy called Ron Covell it is a step by step guide to building a motorcycle frame to your own specification, it also talks you through rake, stretch and trail. You can purchase the DVD here (Ron Covell DVD's) alternatively you can buy this book (link) from the choppers guide website this is also a good site to take a look at, but please stay with me for now there is much more information to gain here before you go.

There are 2 main types of frame used in the construction of a custom motorcycle there is a hard tail frame which is a frame with no suspension at the rear of the bike this makes for an interesting ride you tend to feel every bump in the road and the handling is not great either never the less they area very cool looking bikes (and a must for the die hard riders), the other type of frame is a soft tail, this type of frame has suspension normally in the form of springs and dampers.

Links to frame diagrams and tech reports.   www.chopperhandbook.com this link takes you the chopper builders handbook here you can download plans for different types of frames, they have hard tail frame, soft tail, wide tyre frames. all the diagrams are engineering drawings with dimensions although these are for Harley engines the shapes of the frames can be used, you may have to change the dimensions to suit your needs. but you will find them very useful. In this section there are some other downloads for building some useful tools you may require to make building your frame a little easier like a tube notcher and there is a computer program to help you work out the angles of the cuts for your frame. another useful site is www.mechwerks.com they have similar information as the chopper builders hand book.

Below is a standard bike frame from a Harley Davidson sportster. It is also classed as a soft tail as you can see it has dampers and springs.

The next 2 pictures below show the modification to a standard frame to make it in to a hard tail frame there is no suspension on the rear.

The next 2 pictures are of hard tail frames.