front fork seals loose under retainer - why?

[mikeb]

i'm replacing the fork seals. when the retainer is screwed onto the fork leg, i notice there is about 2.5mm gap between the seal (when fitted into the retainer) and the top of the fork leg. i guess that means the seal can move up and down? does it? It is a tight-ish fit in diameter to the retainer but I would have thought this gap could be a problem and a spacer a good idea.

is this a 'feature' that i don't appreciate? a gremlin or just inconsequential?

thanks!

EDIT: looks like Swarfy has encountered similar issues and posted a remedy:

https://www.a7a10.net/forum/index.php?action=post;quote=118164;topic=14235.0;last_msg=118888

[JulianS]

Just a thought -

A10 seal holders are approx 22mm from end to seat of the seal.

A65 1966-1968 damper rod fork seal holders are approx 24mm from end to seat of seal. Same thread as A10.

The extra 2mm is to allow fitting of the spacer 68 5134 between top bush and seal thus eliminating the dreadful circlip and shim arrangement of the A10 and pre 1966 A65s.

Spacer shown below.

[limeyrob]

No more circlip  I'll miss that, its taken 30 years to master it.

[Worty]

No more circlip  I'll miss that, its taken 30 years to master it.

Still have the circlip arrangement, and the scars to prove it

[mikeb]

Julian - I think that's it! the holders on this bike measure 24mm to the seat, so I now assume they are from an A65 and hence made for the widget, not the circlip. measuring, it looks about 2.5mm gap between seal and seat. i also assume having the seal float around a bit is not great so i either get some widgets, or i've cut some thick rubber 'washers' (46mm od, 35mm id, 4mm thick) to sit between the seat and the seal. the rubber sheet is dampening rubber and will squish down under pressure so i may just try that.

thanks for your help

[Swarfcut]

 Well, fancy finding that post. Another factor is the variable thickness of the seals available. Certainly the seal should stay in place, being a good friction fit. But again, variations in quality mean some examples are a poor fit.

 The later A65 type spacer pictured above is an improvement, holding the top bush and seal in place as the oilseal holder is tightened down. But it is really only single use, as it concertinas down under pressure deforming to fill the gap.

 For dry building up forks, I used a 3D printer to produce a combined dummy oilseal and spacer. Works well, fine for a push around. No flying circlips, easy to demount fork ends.

 Swarfy.

[JulianS]

My experience with the spacer is different, same ones in use for over 25 years and several dismantles later showed no damage to them, they are quite sturdy.