SP: Spring Boxes (Rear) Centralising shock absorber

Albervin

Well Known and Active Forum User
VOC Member
Doing a trial fit and I cannot centralise the rear shock absorber with the spring boxes on F28/2. 16.8mm between mounts to the right and 21.2mm to the left. Is this a problem? Is it critical? I cannot see an easy way to change the set-up. Putting upward pressure on the UFM and all parts appear to move freely. While I am here, is there an easy way to screw the SP1/1 the full amount onto the springs? Thank you.
 

Peter Holmes

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VOC Member
I don't think being off centre will cause you any problems, presumedly the slot that was cut in the UFM was incorrectly or intentionally cut off centre, bearing in mind that early Bs were not supplied with a rear shock absorber anyway, so the UFM my have had an after market slot cut in it off centre, what is important is that the shock absorber operates exactly in line with the mounts and not at an angle, I have found in the past that Koni shocks were not that accurately drilled or the eye not that accurately welded, which is not great for shock absorber operation.
 

Albervin

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VOC Member
Peter, this is an early C Shadow not my B. The shock absorber is an early NOS Koni (the ones that came in orange paint). The slot appears to be mid centre but to my eye is not cut "square". I may take a file to it. I will check the eye of the unit too now you have brought that up. I could ream it and fit a bush maybe but in reality that may be over-kill. I was also going to fit spacers either side of the shock absorber on the F28/2 but it appears they are no longer available so I will make my own.
 

Peter Holmes

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VOC Member
Were spacers ever available? fitted each side of the bottom mount presumedly, if so I was not aware, what I fitted many years ago, but I no longer use, was a suitable spring each side of the lower shock mount, with the springs bearing up to a suitable washer each side of the bottom shock mount, the thinking being was that it would centralise the shock (it didn't) and retain grease and exclude dirt and grit, all fairly pointless, but at the time I was well chuffed with my additions.
 

Simon Dinsdale

VOC Machine Registrar
VOC Member
VOC Forum Moderator
Alyn
The slot in the UFM should not influence the rear damper angle as there should be a slight clearance between the two. The spacers (spring bolt sleeve) F57/2 pull up to the damper top mounting and as the spacers are turned and their end face are 90 degrees to the stud axis it should all pull up straight when the nuts are tightened on the end of front spring stud F28/1.

Now I have found on the occasonal UFM that the tubes that all this fits through (with the slot between them) can have moved out of alignment so check that first and if so they can be persuaded to go back into position. If the slot between them is tight and not at 90 degrees to the axis of the stud and so influencing the angle of the damper then either the slot is not wide enough or the Koni damper top mounting is too wide. Try assembling the damper, spacers F57/2 and stud F28/1 together first without the UFM to check the damper fits at right angles to the stud. If its not at right angles you will have problems with side load as the damper operates on the bike and it will wear quickly.

Simon
 

robin

Well Known and Active Forum User
VOC Member
The rear damper spacer is Pt. No. F57/4ss. Used to be available from the Spares Co.
Reference Price list December 2011.

Robin.
 
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