Need advice on scratched fork tube

Hi all,

My fork tube has a scratch and a few pits in one location and I was wondering what course of action I should take, given that an oem fork tube is $327.72. I decided to see if I could just ride it the way it is, but my seal is leaking oil, so that's a non-option. I've heard that you can buff or sand them out with fine grit sandpaper or oil stones, but the advice on that is conflicting and it looks like the scratch is too deep for that. What are my options? Are replating/repair services available, or should I just bite the bullet and buy a new tube? I was also considering buying a set of used forks on eBay and selling my old pair or swapping parts then selling the forks (of course informing the buyer of the scratch); would this make sense? Thanks. 


Edit: Forgot to add picture. Also, would long seal savers have prevented this?


Edited by Nick Merrell

The only bad idea here is to sand your fork tube. It could fix it but I've found that once parts have to be altered in order to work they just cause more problems. Personally I would just buy a used fork tube or used set of forks 

What bike is this ?

The only bad idea here is to sand your fork tube. It could fix it but I've found that once parts have to be altered in order to work they just cause more problems. Personally I would just buy a used fork tube or used set of forks 


I've read conflicting info on this, so what is the general consensus on this, is it good or bad ?

Or does it depend on depth of the scratch.


That picture looks like it's too bad to sand though.

Surface scratches are ok anything deeper and your struggling

What bike is this ?


It's an 05 WR250f. I'm looking at replacement forks on ebay and I was wondering what years and models I can take an inner fork tube from. For example, could I take the inner fork tube from a 2003 yz 250f? What about a 2002 wr 250f or a 2004 wr 250f?

Super glue in scratch. Let dry. Careful wet sand with fine emery cloth. Works for steering boxes and hydraulic rams. May work here.

Sent from my intergalatic communicator

With a fine file take the high spots off first.

Clean with contact cleaner and fill with liquid metal, epoxy will work just fine.

Sand with 500 wet dry then fill again with super glue and again sand with 500 then I generally work my way up to 1500 wed dry.

It will hold just fine and absolutely no need to replace the tube.

Sand like a professional shoe polisher so you do not take more material than is needed.

If its not too deep of a scratch, what we do to out mtn bike forks when they get scratched is to clean the area well, carefully apply a little clear nail polish to the scratch to fill it in and once its dry take fine like 800 grit wet/dry sand paper or scotch brite emory cloth and carefully sand the area to smooth it out and blend into the rest of the stanchion tube. You just want to smooth it out so it doesn't cut your seals.

Edited by spaceboy

I've tried the superglue method but every time I tried to sand it , it removed all the glue

Use a small emery stone to remove the burr. (Machineist normally use) Then polish with 600 or 800 paper and use a metal filled epoxy. It may not leak without the epoxy. I do not think that you will remove the burr with a file or sandpaper.

I've fixed several with a fine sharpening stone, JB Weld fill, and finish with fine paper then crocus cloth. All worked fine and the last one I did recently was pretty bad. After the initial removal of the raised edges of the damage with the stone clean the depression very well with contact cleaner to remove all oil traces. Fill the damage with JB Weld to a buildup over the surface of the tube and let cure for a day or so. A shallow fill will not pull out during sanding with a good bond.

Edited by GP



I had a pair of USD forks and one slider was leaking oil,  it had bruises from a collision. I used a Dremel with a polishing disc and some polishing compound to polish out the bruises.  Swapped the seal to the other leg, no leaks two years later.

From the looks of it, that tube is done. Sorry. A good rule is if your finger nail can get caught on it then so can a seal which will damage it. Why anybody would jb weld a tube ....? Just don't get that one. Yes sanding does work if it's a very light scratch or wear from the bushings. That's when cross hatching will take that out. That scratch that you have is high on the tube so it's toast. Either eBay some forks or get some TNK tubes from racetech

Like others have said just use one of these to remove the high spots.

Fill or don`t fill the scratch. I don`t fill and I have done ATLEAST 100 fork repairs this way:)

The tube is not even close to done.

The reason to fill is for insurance and to keep that amount of oil and dirt from transferring each time the fork strokes.

Regarding the superglue. After liquid metal is sanded the superglue is just for the microscopic holes. Probably overkill on my part but I have serviced the same forks two years later and was smooth and intact.

I do not know why someone would say the tube is done, that is ridiculous!

Have one customer with a 5" gouge that I repaired about two years ago and I was skeptical due to the size. Two years later still smooth and the seals are still holding up.

Well, I decided to finally fix the tube. I used a 600 grit sharpening stone followed by 1000 grit sandpaper, being careful to only take off the sharp edges. A thin layer of jb weld applied with a makeshift cardboard putty knife worked well. I only have one ride on it, but it's held up so far. Here's how it looks:


Nice work!!



If the JB doesn't stick, just resand and leave the tiny gap open. With the edges knocked off it won't tear the seal and it can only leak the volume the gap holds each compression stroke that causes the seal to cross the gap. Maybe slightly faster seal wear, and f that is a problem, you can always attempt to fill it again. Hopefully the JB holds. Pretty good at sticking to clean metal.

Yeah. Forgot to mention that I used brake cleaner on the tube while it was disassembled before putting down the jb weld. That's a very important step if you want it to adhere well.

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