'93 RM Fork corrosion

[blunlimited]

I bought this '93 RM250 about 3 months ago to get back into trail riding after a 10 year lapse, and while cleaning it the other day I noticed that one of the fork bodies is corroded. The metal has some pits in it (they are more like streaks of corroded areas). I can scratch these areas and the corroded metal will "flake" off. They are not deep, maybe 1/32", but I can't imagine that this is a good thing. The entire section between the upper and lower triples is corroded. I am afraid that the fork body is weak now and could let go on me.

The other fork body is fine with no corrosion at all and has a clear coat on it that is intact. These are "PRO ACTION FORKS, Valve Body Suspension" is what the sticker says on them, I don't know if these are stock forks or if they were installed by the previous owner.

I am concerned about this, and I wonder how I can retard this corrosion and keep it from getting worse - and why it has happened. If anyone has any experience with this or knows why it is happening, please reply.

Thanks all...

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'93 RM250
Off Road suspended minny buggy w/ Tec Star 10 & Comet 40
2002 Panda 50 Fun Rider
2001 PW50

 

[NO HAND]

IMHO, I suspect the material flaking must be some kind of clear coat applied by a previous owner, and not the stock hard anodized finish. The forks tubes are covered at the factory with hard anodizing that is very well bonded to the aluminum and would not peel like what you describe. Actually the hard anodizing is harder than the aluminum itself. If ever the corrosion really has the hard anodized layer peel, I don't think this would affect the strength of the fork tube enough to worry.

 

[blunlimited]

Thanks for the reply. I went back and studied the fork, and I believe that the flaking is the aluminum itself. It is definetely metal that I am scratching, and it is flaking off. This fork looks totally differnet than the other. The "good" fork is shiny because of the clear cote, while the "bad" is dry and gray. It looks like I could take a screwdriver and dig it right into the corroded areas. About 50% of the body between the triples is flaking, while the rest of the area looks like it is right about to start flaking also.

 

[NO HAND]

Woah, this is so bad that the anodized finished is flaking. If I remember right, this means the tubes were not properly cleaned before being dipped it the electrolysis bath for the coating at the Suzuki factory. I don't think this will make the fork weaker enough to be dangerous. It is bad it had to happen to you.