Dirty fork oil syndrome

[JoeMaico]

Wow, two and half years after I started this thread, the discussion is still going on. That has got to be some sort of record. And, it shows that Beta continues to fail at fully resolving the issue. It was on the 2016 CC forks (which is what I have), on the 17’s, 18’s, and 19’s now it seems. The problem is not systemic, as I have always stated. But it is frequent enough to keep TwoWheels busy hard coating all year long.

The symptoms first show up as a chocolate malt looking fork fluid. At least it was for me. I guess it could be a much darker color for some. I am sure the choice of fork oil affects the ultimate color of the fluid. But, in all cases, it is nothing like you originally put in there. Before I replaced my tubes with new hard coated tubes, I was changing the outer chamber fork oil every 10 to 15 hours, to try and keep it clean. Usually one tube is worse than the other (the brake side on mine). But if one fails (or is failing), the other will soon as well. The next symptom that will show up is a sloppy feel to the front fork. This happens when the bushing rides over the worn area of the tube. I noticed it mainly on downhills. But others reported they could feel the sloppiness when grabbing the forks on the stand. When you feel it out riding – it is time to replace the tubes. You could still hard coat them, but they are already too worn to save in my opinion. That was the case with me. Steve gave me a good deal on a set of new tubes and hard coating (I guess because the thread I started was funding his kid’s college education’s). Once you have the new tubes (with new inner and outer bushings, and new SKF seals), you change the oil on a much normal frequency (say every 40 hours or so), and it comes out looking like used fork oil should. In addition, the forks have that new fork feel and they inspire confidence again when you are out riding.
Joe

[moto367]

Yep. I think it was AJ that first mentioned this to me and after checking and measuring my lower triple clamps, I still wonder if that is where the issue lies. I'm thinking the lower brake side bore on the clamp was like .005" smaller than the diameter of the outer fork tube. Have to check my notes for sure. Factor in the torque specs (I torque mine at 84 inch pounds) and you could see a problem. I've been wanting to set my clamps up and re-bore to better size but two wheels' hard coat is working great and I don't want to sacrifice ride time so maybe when the snow flies I'll machine them.