Sanding forklegs

My forks were leaky, and there were black streaks that wouldnt clean off with degreaser, so I replaced the legs. This gave me a chance to play with the old ones.
The first pic shows the streaks and sanding with 2000 grit, which didnt do much.

The 2nd photo shows what happened with red scuff pads, which is about 500 grit.
It did start removing the streaks, so they were above the chrome layer.

The 3rd pic shows them after sanding with 220 grit sandpaper.
The streaks are gone, and the legs turned from shiny to matte. I've heard of people sanding with 320 grit to take some of the mirror finish off, which is supposed to make the seals work better. Not sure if that is true or not, but you can sand pretty agressively and not go thru the chrome. If anyone has the black streaks and are already set on replacing them, I'd give the 320 grit a try.

The last pic shows the seals wiping oil in both directions. This isn't under any kind of pressure, but it still looks promising.

I would try 0000 steel wool and lacquer thinner first.

How many miles on the tubes that you decided to replace ?

Cycledude said:

How many miles on the tubes that you decided to replace ?

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The bikes got 77k. The seals might have just been shot to be honest. I was able to catch a fingernail on the streaks, so I was convinced they were below the surface. Guess not...

What direction did you sand? Around across the streaks, with the length of the tube, or a combination? Mine has some streaking but not that bad at 99k mi.

I do think the All Balls bushings wore more on the legs than OEM bushings.

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I had to do the same. The previous owner changed one of the fork seals and made multiple knicks in the tube while reassembling; likely with a srewdriver trying to get the bushings seated. Gggrrr.

Anyway, I CAREFULLY filed the high spots (burrs) down as close as I dared, then started with 600 grit and worked my way up to 3000 grit leaving a slightly dulled finish and JUST until the evidence was gone,. Sand across the tubes....not lengthwise.

15,000km later and my new fork seal still doesn't leak.

Doing a bit more research afterward, some really bad knicks or chips can be filled with epoxy or JB Weld, then sanded down like I described above.

holligl said:

What direction did you sand? Around across the streaks, with the length of the tube, or a combination? Mine has some streaking but not that bad at 99k mi.

I do think the All Balls bushings wore more on the legs than OEM bushings.

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I made crosshatches. Diagonal one way, then the other.