fork seals

[Monstyr]

I'm expecting my rechromed forks to be delivered fairly soon and I have the first of many probably stupid questions.

The double forks seals- do they both go in the same way up?

[EVguru]

Yes.

[Monstyr]

Terrific.
That was quick, thanks.

[Monstyr]

My lovely new forks sliders have arrived.


I had a quick look at my Harglo manual, it stated fork seals should be replaced with the lip towards the bottom, therefore the spring should not be visible on either of the seals.
When I removed the old seals I do remember seeing the spring, hence the original question, had the previous owner installed these wrongly then?



Oh, and what weight and amount of fork oil is required now ( It says 160cc of chevron atf in one of the books I have, another says 200cc of sae 30 oil), a modern recommendation would be appreciated.

[EVguru]

Many fork/hydraulic seals are double lip and often don't have a garter spring.

[mgelder]

The amount of oil depends on the stroke of the Marzocchi forks fitted tou your bike.

There's a table somewhere in this manual: http://www.ducatimeccanica.com/marzocch ... /index.htm , which is linked to from this page: http://www.realclassic.co.uk/morini05101400.html

The forks on my 82 K Sport took 220cc, for example, but earlier bikes take less.

Use proper fork oil rather than something like ATF that wasn't really ideal when the bike was new and is pointless to use now.

I used 15W to match the rear suspension, changing to 20W when I fitted longer rear shocks which put more weight onto the front of the bike. 30W would be too heavy, 10W might be a little soft.

If the oil you're looking at is just labelled "Medium" or whatever, try and check its actual weight; "medium" for modern bikes if "light" for older ones, and so on.

[MarkB]

On my '75 3 1/2 Strada, which has Paioli forks, I used 200cc in each leg (as recommended in original owners' manual) of 10W fork oil (not engine oil). This worked well but when I replaced the original springs with progressive ones, they were so soft at initial compression that I changed to 15W.

According to the Blue Book, both 350 Stradas and Sports take 200cc in each leg of BP "HLP 80".

Cheers, Mark.

[mgelder]

The Marzocchi manual linked to above is 'more right' than the Blue Book. The latter only refers to one type of fork, whereas several different types of Marzocchi forks were used over the years.