Swing Arm ....Incorrect Information.

[nice2day]

I recently was searching for advice for removing the swing arm spindle and came across the shown page. This has been on the internet for years. Unfortunately nearly all the information is wrong.
The biggest error is when the writer states the following:
It may also be noted that although the swinging arm bush inner is supposed to move with the swinging arm the spindle is not.*

Completely wrong of course. There should be NO movement of the inner sleeve of the swinging arm bushes or the spindle. The whole idea is that the inner sleeves are clamped up rigidly by the end nuts on the swinging arm bolt/spindle very tightly and nothing moves (apart from the swinging arm). This leaves the rubber bushes to flex and provide sufficient movement up and down and there is NO metal to metal rubbing contact anywhere. The correct way to set up the swing arm is to only tighten the spindle bolt tightly when the bike is off the stand and in the normal loaded position thus ensuring the arc of movement of the rubber bushes is limited to an equal amount either way up or down. Failure to do this will have the bushes twisted far more than the design allows. This very same system was used by Norton from 1953. It is incredibly long lasting and my Model 7 still has the original bushes which have not cracked and still flex perfectly. Perhaps this page of wrong info should be removed for the benefit of not confusing other MZ owners?

* Extract from this paragraph:
It may also be noted that although the swinging arm bush inner is supposed to move with the swinging arm the spindle is not. If however, the inner does seize onto the spindle, the spindle can "rock" with the swinging arm movement. With the amount of maintenance that most swinging arms get this spindle will no doubt be seized in the frame as well. In this case (most cases, to be honest) the spindle cannot move because its seized in the frame, the bush inner cannot move because its seized on the spindle so swinging arm movement is accommodated by the rubber bush deforming with the swinging arm movements. This bush is not supposed to work like this (the swinging arm becoming effectively spring loaded) but can cope with it. The extra force of the spring loading works the shock absorbers harder as well, promoting overheating of the shock's oil and hence "fade" of damping. i.e. a bouncy ride.
See the full page here:
http://www.sweller.co.uk/mz/workshop/wrk_swng.html



Les

[Puffs]

Thanks, I didn't know of that page, and find that text a bit incomprehensible. Of course the swingarm hinges elastically on the rubber in the 2 bushes. In summary:

- torque nuts swingarm pivot axle: about 75Nm
- to be tightened in the normal riding position, i.e. with someone sitting on the bike
- grease axle prior to assembly to prevent corrosion.

The grease is not for lubrication, as there will be no movement if you tighten that spindle properly. As with all axles, you grease the axle to facilitate future easy removal.