Doing my research, I found abit about it.
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Figure 1 illustrates the primary chassis components of a typical V-Twin rigid frame that consists of the following primary elements:
1. Steering head. Also called the stem head, steering neck or headstock.
2. Frame Backbone. Sometimes called the Top-tube.
3. Seat post.
4. Backbone or Top Tube brace.
5. Wishbones. One left and one right. Also called the upper rear wishbones.
6. Wishbone cross member. Also called the upper fender mount.
7. Side tubes. Sometimes called the side rails, bottom rails or lower tubes.
8. Seat post cross member.
9. Rear transmission mount/cross member.
10. Axle plates or side plates.
11. Front tubes or Down tubes which extend into the bottom rails.
12. Front transmission mount.
13. Rear motor mount.
14. Front motor mount.
15. Motor top mount.