Fork Seals

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Tim

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Feb 4, 2009
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OK, I know the answer to this question is on this site somewhere. I did a search and can't seem to find it. So here goes, I'm installing "No Leak" fork seals on my '73 Commando 750 Roadster. The directions that come with the seals say nothing about filing a groove in the top of the bronze bushings at the top of the slider, but I know I've seen it done somewhere. Is there a reason to file the grooves, or is my memory totally trashed?
I've got to get it running again before the North Texas Norton Association rally at Lake of the Pines coming up the first weekend in October.
Tim
 
Tim said:
OK, I know the answer to this question is on this site somewhere. I did a search and can't seem to find it. So here goes, I'm installing "No Leak" fork seals on my '73 Commando 750 Roadster. The directions that come with the seals say nothing about filing a groove in the top of the bronze bushings at the top of the slider, but I know I've seen it done somewhere. Is there a reason to file the grooves, or is my memory totally trashed?
I've got to get it running again before the North Texas Norton Association rally at Lake of the Pines coming up the first weekend in October.
Tim
Click to expand...

Not the answer to your question, but I've never gotten a pair of "no leak" seals to hold oil (think Exxon Valdez)...whereas the standard Norton parts never seem to develop leaks. Not sure why there is a "no leak" product required.
 
The standard seals began to leak after I tied the bike down on a trailer, with the forks compressed, and towed it several hundred miles. I'm hoping the "No Leak" seals will allow me to trailer the bike when needed without causing the forks to leak. We'll see how it works out.
Tim
 
Tim said:
The standard seals began to leak after I tied the bike down on a trailer, with the forks compressed, and towed it several hundred miles. I'm hoping the "No Leak" seals will allow me to trailer the bike when needed without causing the forks to leak. We'll see how it works out.
Tim
Click to expand...

One of the tricks to trailering and protecting seals is to take the front fender off (relatively easy on a Norton) and place a 2x4 (or suitable substitute) between the lower triple clamp and the tire. Then cinch down. That allows you to take the pressure off the seals.

Fork Seals

Fork Seals

http://www.motorcycle-superstore.com/2/ ... &zmap=4170

I've seen this several times in the vintage MX world so don't give me any credit for it. You may want to add stabilizers to the board or play around with it. You don't want the board to come out. That would be Bad. Or you can just buy one, and since they are about $20 I'd go that route.
 
That's good to know, I didn't. I plan on getting a trailer for my '69 because at my age I can't take a whole day on the bike.

Dave
69S
 
I just installed two new fork seals, standard ones, in my 73 850.

Never heard of making, filing, grooves anywhere.

It's just a fantasy!
 
It was me who posted on filing the grooves. You can find on my site in the directions for a Norton fork kit. Because of how they work some extra oil just under the seal seems to make them last many years. I have done 6 bikes on my trailer many, many miles no brace, no blown seals or leaks. Many seem to have problems but I have never had a set fail. Many sets installed many miles rode.
 
Interesting as I never understood how constant moderate trail compress hurt seals more than road loads. Any who pre-Peel came with her top bushes oil spiral grooved. They have some annoying slack but not as much as two other new bush pairs I tired. So maybe groove is preserving as Greg states.

Will have to think up a way around removing fender if trailing is such a hazard to seals. Was thinking of way to hang bikes to relieve suspension but a bother to construct.
 
Thanks everyone for the good advice. I never thought of putting a board between the tire and the triple clamp. Norbsa, it was your post on the grooves that I remember (haven't totally lost it after all!) My plan is to install the "no leak" seals with the grooves filed in the bushes. If that doesn't work and the "no leak" seals leak, then I'll install standard seals and buy the device on Swooshdave's post. I'll let you know how it turns out. The trip to Lake of the Pines, TX on the trailer in October should tell the tale.
Tim
 
Tim said:
Thanks everyone for the good advice. I never thought of putting a board between the tire and the triple clamp. Norbsa, it was your post on the grooves that I remember (haven't totally lost it after all!) My plan is to install the "no leak" seals with the grooves filed in the bushes. If that doesn't work and the "no leak" seals leak, then I'll install standard seals and buy the device on Swooshdave's post. I'll let you know how it turns out. The trip to Lake of the Pines, TX on the trailer in October should tell the tale.
Tim
Click to expand...

OK to TX isn't that far. I'd be more worried with a multiple thousand mile trip.
 
Gday Tim , just wondering which leak proof seals you went for as theres the standard ones and now "pro-moly" leak proof. The difference being the first leak proof design had a coating of moly which after time wore off and now the new improved pro-moly has the moly moulded throughout the seal. Pro-moly comes with a lifetime guarantee against leaks, so long as you're the installer/owner. Ive purchased these for my special thats slowly being built.
foxy
 
Foxy
I'm not sure which type I have, but they were recently purchased from Old Britts here in the states and they state on the package they are guaranteed for life. I'll keep you posted on their success.
Tim
 
Ok once seals determined and placed, what has group mind found to be most enduring fork gaiters? Two years of non weather and use exposure made last set come apart even w/o seal leaks helping.
 
It's a big pain to remove the front fender just to trailer your bike. How much oil is coming out? More than a couple wipes with a rag? Holy cow!
 
No not just a wipe up from travel weep, its claimed to cause permanent seal damage and weeps there after, so all the effort to avoid replacing seals after a trailer trip. I know I bottom forks routinely w/o undue weeps so don't understand the cinch down issue but its like a motto among vendors and race crews.
 
Fork Seals


This picture is somehow sticking in my mind with the piece of wood concept.
 
UM, my brain is stuck.
How can trailering a bike harm the seals?
Surely, if it does that, then riding it (God forbid) would certainly blow them to pieces.
 
Flo said:
UM, my brain is stuck.
How can trailering a bike harm the seals?
Surely, if it does that, then riding it (God forbid) would certainly blow them to pieces.
Click to expand...

When you are riding the forks tend to return to the normal state a majority of the time. They are only at compression for a short while.

When tied down they are at full compression and thus (correct me if I'm wrong) but the maximum oil pressure. Add in vibration and several thousand miles of trailering and a seal may give out.
 
swooshdave said:
Flo said:
UM, my brain is stuck.
How can trailering a bike harm the seals?
Surely, if it does that, then riding it (God forbid) would certainly blow them to pieces.
Click to expand...

When you are riding the forks tend to return to the normal state a majority of the time. They are only at compression for a short while.

When tied down they are at full compression and thus (correct me if I'm wrong) but the maximum oil pressure. Add in vibration and several thousand miles of trailering and a seal may give out.
Click to expand...

Maximum oil pressure requires a velocity, the pressure in the forks due to being tied down is the reduction in volume compressing the air in the forks, I can see how this will cause the seals to weep but other than that it wont cause any damage, just wipe up the oil when you take it off the trailer. If it is a big problem you could always but bleeders in the fork caps.

A word of caution on the spacer between the wheel and the triple clamps though, if for any reason the spacer comes loose (flat tyre or the like) you will not have any tension on your tie downs anymore.
 
Cheesy said:
the pressure in the forks due to being tied down is the reduction in volume compressing the air in the forks,

If it is a big problem you could always but bleeders in the fork caps.
Click to expand...


Why not simply slacken the fork caps by a few turns before the bike was tied down to allow the air pressure to escape, and then re-tighten them when the forks are compressed (not forgetting to let the air back in again-once the forks were released)?
 
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