SOHC.co.uk Forums > CB350/400
Fork Seals
McCabe-Thiele (Ted):
I know we call them rubber seals, I suspect (as we know) they are primarily a type of plastic, perhaps more modern fork oil contains the plasticisers to keep them supple?
Although I didn't use ATF in mine, the later ATF's definitely contain plasticisers to keep seals supple.
Otis:
--- Quote from: McCabe-Thiele (Ted) on July 28, 2026, 09:42:56 AM ---I know we call them rubber seals, I suspect (as we know) they are primarily a type of plastic, perhaps more modern fork oil contains the plasticisers to keep them supple?
Although I didn't use ATF in mine, the later ATF's definitely contain plasticisers to keep seals supple.
--- End quote ---
I think that is so very true. When having reached a certain age and having dealt with older technology it's easy to overlook the very significant improvements in materials and fluids.
Bryanj:
At a certain age ALL fluids are a problem!
Oddjob:
I’m trying an experiment with my 550 fork seals. For some reason the space left by Honda is deeper than the fork seals they used. So that meant either a gap above or below the seal and the circlip holding it in place. Didn’t seem right to me so I looked around and found some genuine Honda seals that were the same external and internal size but were wider in depth. Seem to remember it was an off road bike and not imported into the UK so I was forced to source some in the USA. Not tested them yet but they are double lipped as well.
Oh and they come with a spacer as well, so I can fit the standard seals if I want but with a spacer underneath. Seems like a result.
Bryanj:
Ken, i seem to rememberreading somewhere that the height of seals changed, 13mm and 11mm come to mind but dont quote me, maybe check the veru old 750 parts book in Ashs stash(ex mine)
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version