Head steady fitting

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johnny Lagdon

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Refitting a standard 850 box section head steady to a '73 850 bike that had sat for 10 years. I have replaced both m,ain iso's and have new rubber bobbins that screw into frame. when you sight down the flat of the bobbins to the sides of the deady steady box section, they do not line up, and the discrepancy either side is not equal. As my other bikes have after market head steadies I have no experience of fitting a standard one. should I add shims/spacers to get things to line up when the side plates are fitted?
 
The engine does not sit dead center to the backbone when viewed from above. Normal so the head steady plates are to the left a tad. There was a thread where it was discussed.
 
Thanks, I have clearance both sides of the side plates when mounted to the screwed in rubber bobbins. Seems to me that there should be some kind of spacers or shims to make them level with each other, or when you tighten the nuts on the through studs it will distort the rubber between the bonded steel plates and prematurely damage them.
 
Do you have the spring & saddle rig? Proper tension on it BEFORE installing the bobbins, might be the best course of action, unless it's contrary to the shop manual...
 
Do you have the spring & saddle rig? Proper tension on it BEFORE installing the bobbins, might be the best course of action, unless it's contrary to the shop manual...
No, but i cant see that the MK3 saddle and spring gizmo would make any difference to the air gap that exists in 2 parelel planes 90 degrees to fore and aft which is the pull of the suspensory spring device. the box section is 2 33/64" wide, and with the bobbins seated in the frame threaded lugs and the side plates mounted they are 2 23/32" apart. This leaves a gap of 13/64" distributed between the 2 sides.
 
The difference between fat & skinny bobbins?
IE there have been different width bobbins sold by various suppliers over the years.
 
Before making and fitting my Ludwig style head steady , I used to make sure those rubbers were equally under compression. You can add washers between the bobbins and the brackets.
Those brackets can bend though.
 
Before making and fitting my Ludwig style head steady , I used to make sure those rubbers were equally under compression. You can add washers between the bobbins and the brackets.
Those brackets can bend though.

Can you please explain the Ludwig style head steady ?
 
Can you please explain the Ludwig style head steady ?
Head steady fitting
 
Seems to me that there should be some kind of spacers or shims to make them level with each other, or when you tighten the nuts on the through studs it will distort the rubber between the bonded steel plates and prematurely damage them.

the box section is 2 33/64" wide, and with the bobbins seated in the frame threaded lugs and the side plates mounted they are 2 23/32" apart. This leaves a gap of 13/64" distributed between the 2 sides.

Tightening the nuts on the through-studs will compress the rubber mounts slightly as the plates will tighten down parallel to each other and I've never known it to damage the mounts.
It does mention in Norton Service Release N3/51 that tightening the fittings pre-loads the rubber mounts.
 
Leave all the fasteners loose until it's all assembled.
When fitting my DT headsteady I had fun discovering just how much the motor can move by sitting on the bike with the stand up and leaning it left & right.
When the bike is on the centrestand the motor is already under stress, and not sitting in its neutral state.
Agree that the standard headsteady isn't the best, but Johnny is already familiar with that, I suspect ;)
 
Leave all the fasteners loose until it's all assembled.
When fitting my DT headsteady I had fun discovering just how much the motor can move by sitting on the bike with the stand up and leaning it left & right.
When the bike is on the centrestand the motor is already under stress, and not sitting in its neutral state.
Agree that the standard headsteady isn't the best, but Johnny is already familiar with that, I suspect ;)
Your suspicions are well founded!
 
...I cant see that the MK3 saddle and spring gizmo would make any difference to the air gap that exists in 2 parallel planes 90 degrees to fore and aft which is the pull of the suspensory spring device. the box section is 2 33/64" wide, and with the bobbins seated in the frame threaded lugs and the side plates mounted they are 2 23/32" apart. This leaves a gap of 13/64" distributed between the 2 sides.
The spacing should be correct, or not off by much, unless the rubber buffers are REALLY bad knock-offs.

The spring has a specific purpose, and is beneficial to ANY head steady, for the job it does.
 
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