My fork seals have started leaking after less than 10000 km
Next time I change them do I use wet sand paper and then polish
what type of sand paper grit and polish
What brand fork seals are good
Best to use Yamaha fork seals or get them from RPM Randy.
The cheepo seals will leak in a hurry.
As for polishing the legs, I use an old crankshaft polishing belt with wd-40. If you are anywhere near an automotive machine shop , you can get one for the price of a beer and a funny story.
Emery cloth is the other way to go.
Use a paint stripper to get the clear coat off...don't sand it. After that, use progressively 400/800/1000/2000 grit wet/dry paper. Fold the sand paper so you don't get pressure spots. Use this paper wet. Get a spray bottle. Keep the paper and aluminum surface wet. Spray lots of water, it keeps the paper from loading up. Sit in a chair with a folded towel draped over your knees. A wet crotch is uncomfortable.
Avoid ripples. Long even strokes. Take your time. Sing to them while you sand, they'll be happy.
Finish off with multiple coats of Simichrome
Figure about 1 hour per leg. It's fun. The results are worth it.
Uh, I took it to mean he wanted to polish the legs the seals slide on.
Quote from: Mark Olson on November 21, 2015, 10:26:59 PM
Uh, I took it to mean he wanted to polish the legs the seals slide on.
That was my understanding as well. Next time you replace your seals also replace the slide bushes. You may have some wear in them allowing lateral movement at the seals. Always polish the chromes slides in a circumferential direction not longitudinal, scouring pads are usually sufficient to do this job.
Regards, Pete.
The title was "polishing the fork legs" so that's what I went with.... :flag_of_truce:
On the stanchion tubes: yeppers to Pete and Mark....circumferential with scotch brite pad
Here is something to look at before you pull the front forks apart. I can't vouch for it even though I have 2 or 3 of those Seal Mates somewhere around here. I have never used one.
https://www.youtube.com/watch?v=nEzjdFQp6IM
If you have to replace the seals then as recommended, use the Yamaha seals.
Thanks for the advice, I did mean polishing the fork legs so the fork seals do not wear out as quick
I have replaced all the fork slide bushes but i did not use yamaha fork seals
Are rpms fork values and springs really as good as the website and people go on about
I do like stiff suspension but the small bumps get annoying on the standard setup
Yes the RPM Fork Valves/Race Tech Spring combination means you don't need grip the handlebars with every ounce of strength when hitting sharp bumps at highway speed.
About a year ago I did the front and rear wheel swap, the forks I got off the web were bent so I just used the lowers with the seals that they came with. One of my old forks had continued to leak even after a seal change
I don't know what seals are in the the legs I got off the web but they have not leaked since I put them on... must be an original part or a Randy replacement.n
The key is to "polish" the fork tubes. If you scratch the chrome plating they will leak sooner and more than before.
You need to use a fine grit "crocus cloth" only on the chrome plating.
If you have some worn-out scotch brite pad then you can use that too, but if new it scratches the chrome too.
Also you cannot run any abrasive up & down the length of the tube, it should only be polished around the circumference as you slowly go from the top & bottom. If you go up & down you are just putting gouges in the chrome that allows the oil to leak by the seal.
Then you need to use the N.O.K. brand seal, which is what Yamaha supplied, which has proven to be the best seal for the application.
I have the NOK seals in stock; RPM Fork Seal Kit (http://rpmracingca.com/proddetail.asp?prod=M%2FC%3AFJ41ForkSealKit)
Yes, the RPM fork valves are all that you have read and more... :hi:
Randy - RPM
It's nice if you can chuck them up in a lathe.
Can't let this slide...
The only thing you should be using to "polish" the fork tubes is a clean rag. The seals rely on an almost-mirror finish to work. If you are using something that leaves any kind of mark on the chrome, you are ruining it.
Now, having said that, if you have a stone chip that raises metal above the surface of the chrome, you can salvage the fork tube by using a very smooth file to gently file the offending metal down to the surface of the chrome. This way, at least the raised edge won't be snagging the seal every time it passes by. It won't be a proper fix, but the alternative... replacing the tube... just isn't feasible.
But if you have scratches which are below the surface of the chrome, you are not going to sand/grind/file/polish the surrounding area down to the level of the bottom of the scratch. And adding more scratches... "polishing"... isn't going to help.
The worst thing the bike makers ever did was to get rid of the rubber fork gaiters, just because "real" racers don't use them. Dumb...
Bill
Hi
I can get fork tubes redone up here at North American Chrome in Burlington But the bloody bent tubes they cant do because now a days they are thin wall and are easily dented.
Chiz
Exactly, Bill, you cannot scratch the chrome surface.
FYI, replacement fork tubes (http://rpmracingca.com/proddetail.asp?prod=m%2Fc%3Aforktube) are available and in stock.
Randy - RPM
Quote from: racerrad8 on November 23, 2015, 09:53:16 AM
FYI, replacement fork tubes are available and in stock.
$230 for a new tube? That's actually not a bad price. I sure wouldn't try to make one knowing that I could get a new tube at that price.
Just a data point... I'm currently making a nose landing gear strut for a customer's Experimental airplane. To get the inner tube hard-chromed was $250. That's one piece, 1.5 inches in diameter and a foot long. That's 250 bucks, just for the chroming.
Carry on... :drinks: