Fork seal stiction(2019)

If you're already using slippery synthetic fork bushings then there is still some unwanted stiction due to the fork seals. So how do you get rid of it and what are the options?

First there is the standard Norton fork seal. This seal probably has the lowest friction because its a single lip. This seal will last and last if you have accordion fork gaiters installed. But some people want to see the shiny fork legs and that means abrasive dirt being scraped off by the oil seal.




Below are the Honda fork tube oil seals 91255-KBH-003 These have a dust seal, an oil seal and two springs so they probably have a little more friction. They last longer and hold oil better. But they need to be trimmed on the OD to fit.




A more popular alternative is the Ariete Fork Oil Seals part number ARI003T. These have two lips as well as two springs like the Honda seals above. I'm sure they hold oil better but the 2nd spring and lip probably increases the stiction.



Then there are the "leak proof" oil seals. I tried these and they add way too much sticktion. Oil tight yes but not worth the harsh ride.


Below is a photo of my ride with synthetic bushings, stock fork seals and accordion gaiters. Its the best combination I know of so far and I don't mind covering up the fork tubes. If someone has a better combo - lets hear it.

Look at this, SKF green seals.



Issue is the nearest of their 35mms seals is undersize on the OD by 0.6mm, but with sealing washers top and bottom coupled with sealant on the OD the seal holders should be able to stop any leaks.

Over 43 years I was replacing the fork oil seals from leaks on a regular bases but since about 7 years ago putting on fork gaiters I haven't touched my stock oil seals since and now only replace the fork oil when needed as part of maintenance, keeping the dirt and crap out of the seals is better than having shiny forks in my book, I also think the gaiters look better.
I have over the years tried every fork seal combination around to have the seals still leak, the non leak seals lasted less than the stock seals, I even had 2 slim seals with 2 lips on each seal in each of my forks and they lasted a bit longer but still failed, but now stock fork seals with good quality gaiters and normal fork maintenance and my seals have out lasted the best so far, 7 years now and still no leaks, moister in the oil is also the biggest killer of fork seals and it seems to be one of the biggest lack of maintaining the forks on a regular service that people seem to forget about.
So am with you Jim, stock seals, good quality gaiters and regular maintenance and your bike will luv you for it and less work in the long run.

Ashley

I just did mine a couple of months back with new stanchions which I hope to never have see the light of day. When these gaiters tear they'll be replaced quickly because I don't like front end work, but do like it to work right. Stock seals & bushings also seem to work well enough for an old fart.

kommando - what's the part # for the green seals (close fit for Norton)?

Jbruney - The gaiters I have are not tearing. Some are made of better rubber that don't seem to break down.

I can only hope this pair is good, if not I'll replace with some from another source... As long as I keep the poo poo out I'm good. Sometimes I feel as if I'm a lab rat.
jseng1… I love the look your nasty girl has about her. Good lines & all business.

The SKF green seals are a whopping $36 retail per seal because they come with a 2nd dust scraper seal for KTM/Husky dirt bikes. They are a dual lip, dual spring seal measuring 35x46x11mm (closer to 46.3mm OD). Part # 35W. The seal recess in the slider is 47.75mm so it would need a spacer (approx .75 thick).

There are 2 ranges of SKF Green seals and dust protectors.

The Motorcycle range of kits

http://moto.innteck.info/index.php?pg=products&tree=137

and the dimensions for these is in this pdf

http://moto.innteck.info/media/documenti/DimensioniSeals.pdf

In the UK you can get single seals without having to buy the dust protectors

https://www.twsgb.co.uk/skf-motorcycle-single-fork-oil-seals-457-c.asp

They also cover Mountain pushbikes but size info is hard to find but they are 35mm ones, just can't get the sizes.

This may be one of them but not got it confirmed or a source of just the seals

35M 35mm MARZOCCHI seal 35 x 47 x 10 Dirt scraper 35 x 47.4 x 4.9

Finally got a good set of gaiters , 3rd try was the charm .... Andover sent me ,from what I can observe compared to last 2 sets a very heavy duty pair and so far very pleased .... the others failed within a year or two ,they were marked UK maybe package was but not gaiters

Craig said:

Finally got a good set of gaiters , 3rd try was the charm .... Andover sent me ,from what I can observe compared to last 2 sets a very heavy duty pair and so far very pleased .... the others failed within a year or two ,they were marked UK maybe package was but not gaiters

Click to expand...

Where did you get the gaiters that failed from?

My gaiters from RGM have been on my Norton for over 7 years now and are as good as the day I put them on no slitting at all, I also use their SS clamps for the gaiters.

Ashley

since they offered me only a credit towards my next purchase I will say BritCycle , sent me two different sets of fork gaiters that both split to pieces in a hurry , this with very little ride time , mostly sitting in heated shed never in the sun unless moving .... they offered to credit my account ( not back into my CC) to be used for new purchases .... lame

From memory - I think that what you want for gaiters has some natural rubber in it. Mine have been perfect for years.

Life long mx rider and I take care of friends bikes. The SKF green seal really work. If theres a way to make them fit it will be worth the effort

kommando said:

There are 2 ranges of SKF Green seals and dust protectors.

The Motorcycle range of kits

http://moto.innteck.info/index.php?pg=products&tree=137

and the dimensions for these is in this pdf

Click to expand...

Discussing the application of these seals entail enlarging the fork tubes to 35.00 mm (stock fork tubes are 34.52mm). SKF does not supply seals which fit stock tube diameters unfortunately, and fitting 35mm seals will likely fail to seal due to insufficient tension in the lipped seal.

On the other hand, adopting 35mm stanchions to the Roadholder fork is an interesting subject, but I doubt anyone will consider such a move in order to fit these seals.

What kind of seals are Cosentino / NYC Norton offering?

- Knut

mdt-son said:

fitting 35mm seals will likely fail to seal due to insufficient tension in the lipped seal

Click to expand...

True but all the other seal alternatives such as the Ariete and the Honda are also for 35mm stanchions but still seal so there would seem to be enough give to cope with 0.48mm.

mdt-son said:

What kind of seals are Cosentino / NYC Norton offering?

- Knut

Click to expand...

Not sure, but they say they are double lipped.

It kinda looks like a better job of turning down the Ariete seals than I must have done.

gortnipper said:

Not sure, but they say they are double lipped.

It kinda looks like a better job of turning down the Ariete seals than I must have done.

Click to expand...

I guess the holders are machined to fit, nullifying the need to "adjust" the seals ?

I know Ludwig use the ARI , so for me it was a good reference , and I had fitted them with no leaks .