Author Topic: 1983 XV500 Cafe Racer  (Read 57972 times)

Offline jpmobius

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Re: 1983 XV500 Cafe Racer
« Reply #230 on: Dec 24, 2018, 20:43:27 »
It is important when examining these things to stay focused on the individual elements.  The kinematics, or mechanism of how the shock is actuated is completely unrelated to the swing arm itself.  The actual swing arm, that is the link that goes between the rear axle center and the axle center that the arm pivots on could point in any direction.  What matters is the link that goes between the pivot the swing arm rotates on and the  pivot the lower shock mount swings on.  If you align your square on this link, you will appreciate how much larger that 90o this angle is.  Obviously, since the lower shock pivot is welded onto the swing arm, the relation between the orientation of these two "links" is fixed, and so the one must depend on the other.  Perhaps it would be helpful to imagine two individual swing arms.  The one you have, and another tiny one that only goes to the shock with the two welded together.  That is actually what you have, it just does not look like it because the primary visual feature is the tube that makes up the main arm.  Your shock is not aligned with that arm, so you have to imagine what the arm that actuates the shock would look like to get a handle on the angles that are important. In fact, the tubing that makes up the arm is equally irrelevant when analyzing this (or any) system.  It of course makes sense to align the tube on centers of the "link", but think on those "banana" shaped arms needed for exhaust clearance.
 The link is still center to center, and the angle of the banana is irrelevant.  It is often quite easy to misinterpret mechanisms when the pivot centers are not directly in line with their connecting structure - you have to see past the visual illusion.  You can do this easily by making a diagram that has only the pivot centers drawn the correct distances from one another.  Do that, and you will see that the link to the shock is a long ways away from that to the axle.
« Last Edit: Dec 24, 2018, 20:46:40 by jpmobius »

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1973 RD350 Yamaha build

Offline Karlloss

  • Posts: 232
Re: 1983 XV500 Cafe Racer
« Reply #231 on: Dec 25, 2018, 07:54:57 »
Yes I see what you mean. The original reason for changing the lower mount was to ensure clearance between the rear wheel and shock. No that is has bags of room I will move the lower mount back and down. Live and learn hey.

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