E.Marquez

Looking for input from those that have a fork brace on the OEM forks.

Are you having seal leakage problems?

I have a second seal leak in 12 months after the forks were professionally gone though (and that work quality is not in question at all, yes Im sure)
So they started fresh, had a right leg leak, disassembled, cleaned, checked for run out on the stanchion, and any damage..CLEAN as can be. Did NOT do both fork legs.
New OEM seals, bushings looked to have minimal wear so did not replace.

Few months later, now I have a left leg seal leak.
It'll come apart tonight.. Im betting i find the same thing, no leg damage, straight tube. Crap in the seal.
I've tried the old wipe the seal clean with film negative trick (well I used the motion Pro tool for this) It does pull out some debris, but the leak continues.

I theorized it might be dried bug guts on the tube damaging the seals.. But was advised while it might cause a leak due to crap in the seal, bug guts would not likely damage the seal.

I do not have the OEM "guards" installed. at this time.. Ordered some carbon fiber tube and will make/install some.

It was suggested that the fork brace may be causing the leak.//// I don't think so, but it's a reasonable concern.
I see no weird wear pattern on the bushings as if the leg is being deformed or forks out of alignment (twisted) or being forced to travel in a non linear manner.

But so is it the fork brace? Is it just crap getting in the seals (that means stuff getting past the dust wiper as well)
Is it something else or just, seals leaking.... due to use (only about 8k miles since full rebuild where the seals were not replaced,, they were less than a year old at that time and the suspension builder said they looked good. I trust his judgment.

In goes some SKF seals...tonight, fresh oil, new upper and lower bushings... What i need to decide is, reinstall the brace or not....

thetophatflash

In my experience, dried bug guts can be extremely hard and abrasive. I use silicone spray to clean off the fork tubes when they are extended and crocus cloth to deal with the occasional rock ding before most rides. Unless the brace is restricting fork action, I doubt that the brace is the problem. As the brace mounts, does it leave any space that might collect small abrasives? Also, I would always replace the seals if I went inside the fork. In my work I've seen many a seal that looked good fail. There is a strong possibility that the wear pattern on initial installation was aggravated by the fact that the fork tube and seal were in a different relationship when reassembly took place.

HawkRider98

Been using a Superbrace with their metal guards and stock guards on stock fork for years, no problem.

NZSpokes

How often do you grease you seals? This effects seal life hugely.


I run a brace and have no trouble but grease my seals every 3 months.

E.Marquez

Grease the seals, umm never in about 38 years. Grease attracts dibres and holds it there next to the stanchion.

If it works for you , good..nothing wrong with that.
I have enough good experience with seal longevity doing it the industry standard way, my bikes, and my customers, friends, ect..LOTS of bikes over the years ..I'll stick with it for now.

I've got many years and 10's of thousands of miles on the same bikes, never greasing the seals (which are not designed to be greased, and not reccomended by any suspension tuner I know of other than to aid assembly) So thank you for the suggestion..

This is the only bike in 38 years I have had that MIGHT be a seal issue. So I'll look to tracking down what is worng, vice adding a new variable to the mess.

NZSpokes

I got taught it by Dave Moss. He may know a bit about suspension.

Ive been rebuilding suspension on various things for decades. Its part of my job.

But hey, feel free to ignore me. Up to you.

E.Marquez

Well that did not come across as expected..

Ignore? not at all, listen, consider and make an informed opinion.. Yes.. That opinion differs from yours is not disrespect, just different.
Dave Moss , nice. Never met him, but know about him.. Well respected suspension tuner.

That said, greasing the oil seal (or did you mean dust wiper?)
Greasing with what? Like an assembly lube (I use race Tech) or something else.
What problem are you addressing with this seal greasing? What down sides do you find?
Are we talking a race bike that has the suspensions ervice often? or a street bike your expecting to go 2, 3, 5 years before servicing?

Im open to all new ideas,,, but doing a drive by with an unorthodox suggestion and NO support and justification for the idea left little to comment on.

Part of your job is to grease seals? So you're a general bike tech? work at a suspension shop? Own a suspension tuning facility?

Im all ears, tell us what, how, why

E.Marquez

Well that did not come across as expected..

Ignore? not at all, listen, consider and make an informed opinion.. Yes.. That opinion differed from yours initially and was not intended as disrespect, just different.

Dave Moss , nice. Never met him, but know about him.. Well respected suspension tuner.

That said, greasing the oil seal (or did you mean dust wiper?)
Greasing with what? Like an assembly lube (I use race Tech) or something else.
What problem are you addressing with this seal greasing? What down sides do you find?
Are we talking a race bike that has the suspensions ervice often? or a street bike your expecting to go 2, 3, 5 years before servicing?

Im open to all new ideas,,, but doing a drive by with an unorthodox suggestion and NO support and justification for the idea left little to comment on.

Part of your job is to grease seals? So you're a general bike tech? work at a suspension shop? Own a suspension tuning facility?

Im all ears, tell us what, how, why

E.Marquez

https://www.facebook.com/davemosstun...29748807035279

NZSpokes, thanks for making this suggestion, I'll be doing some digging on the concept.

I honestly had never heard of greasing an oil seal for other than assembly. Interesting idea..

kenmoore

I have a brace and no problems. Don't have the guards fitted either!

The numbers would suggest that you have either been unlucky, or got a bad seal, or something is amiss with a component in your fork assembly.

NZSpokes

Im the technical adviser for the biggest bicycle wholesaler here. Im the guy the mechanics talk to that have problems servicing parts which include suspension systems. Bicycle systems are on a par are more advanced than motorcycle systems. Ive also spent years building racecars, offroad racers etc.
The procedure for greasing seals is very simple. Lift the dust seals, this can normally be done by hand. Lift it all the way up. Clean out the area above the oil seal. Put some grease above the oil seal, I use Manitou M prep because I have it at hand but it is very good at reducing stiction. I believe it is another product re-boxed but unsure of its original name. Push gently down on the bars so the grease makes a nice ring around the fork above the seal.
Then lift the bike off the side stand and make sure you have a good balance of the bike. Grab the front brake. With an explosive effort push down hard on the bars. This will cause the seal to flare and let the grease in under the seal. I do this twice. Then refit the dust seal. Wipe down the fork leg.
If it takes more than 10mins you are doing it wrong.

It is common to find a fork that has a high level of stiction due to dry seals. Some forks it will act as if it has very high compression and rebound settings. It can bring riders down. It is also a major contributor of fork seal wear. As a fork legs chroming wears due to dry seals and the seals wear you get leaks. Also those that don’t clean the fork legs may get issues with dirt ingress. Dry seals are more likely to allow dirt in.
I would as part of normal servicing replace the bushes each time I replace seals. And dust seals must be replaced at the same time as oil seals. If the crosshatch on the chroming has worn then sometimes going over it with scotchbright will help get some more life out of the fork tubes.

rick

Greasing seals is now becoming increasingly recommended. Racetech sells a product for it and recommends it. I don't believe not re-greasing is what caused you seals to fail. More likely bad seals in the first place or forgetting to lube the seals with fork oil.. The fork seal grease can extend the seal life much more than without ( especially on bike's that sit long periods like track bikes). Dave Moss did recommend seal grease to me also. I remember him talking about it helping reduce stiction more than seal life as the main benefit.

E.Marquez

The race tech seal grease has been around for many, many years. And it is recommended to use some for assembly..But I've never seen it recommended by they as a service or maintenance task/ need...

I've installed 4 front and rear RT setup last month and have a front and rear set up to install today.. Im pretty familiar with what they have to say at least in written format. Did you go to one of their suspension course or something and get the greasing recommendation?

Im not turning my nose up at this idea at all, just trying to learn of it now. It seems to be a recommended thing from a few tuners, but not wide spread. Headed into the shop my wife works at, the senior Tech is an Oliens certified Tech that has raced and worked for several world superbike teams.... he is the guy that does my Dyno runs as well... I'll ask him ..perhaps this is a long standing "trick" I just never picked up. Happy to learn something new.

rick

No. I did not go to a RT suspension course. I am relatively new rider too. So my knowledge on the subject is very limited.

I was just reiterating what have been recommended to me recently by suspension shops around here. I started greasing the seals on my track bikes recently. Previously the fork seals on the track bikes used to weep a little when it was moved for the first time after a few weeks. The weeping would stop by the next morning.
After I started greasing it, that behavior stopped.

The reason I said it is becoming increasingly popular is because you mentioned you never heard of it. I don't remember reading about re-greasing the seals a few years back when I stated working on my own bikes either. But lately most shops here recommend it .

NZSpokes

I suspect the cause of this failure will be worn hard chroming. Easy way I have found to test this is with the fork apart run a new seal over it by hand. If it gets very easy to move over the seal area of the leg then its getting past its useful life.


I would either try it with an AllBalls seal kits as they are tighter or replace the legs.


I fixed a Honda 919 with this issue a couple of months ago.

E.Marquez

Thanks for the suggestion, however Stanchions are straight, dent and nick free and hard chrome not worn. So dimensionally they are fine as is the chrome surface.
In many years of use, Alls ***** fork seals have failed early more times then I care to remember.. SKF or OEm these days for me and the bikes I support/ work on / own. I understand others will swear by the other off brands of seals but the only thing I can do is sware at them

NZSpokes

Reason I suggest All ***** on worn legs is due to them being a tighter fit and can get more life out of a pair of legs that are worn. But I agree they wear faster than OEM ones.

kenmoore

Next time I am in the Man Cave working on the VTR I am going to try this grease trick.

Can't hurt eh?