Fork Operation

Discussion in 'Tech Area' started by Dennis McDonaugh, Mar 24, 2020.

  1. Dennis McDonaugh

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    I'm going over the bike to see what might need to be rebuilt what just needs cleaned and came to the forks this morning. There's a lot of up and down play in them and the little chrome gaiters also move up and down. I don't think there is actually any oil in the forks now. This isn't normal right?

    What parts are normally replaced during a rebuild?

     
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  3. racerx

    racerx Administrator
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    K1 are gatorless forks, i.e. no rubber gators (boots), a one-year-only setup.

    Looks like your seals have been leaking for a very long time now. That's not a bad thing, as restoration projects go. You'd be surprised to know how many owners have faced a major battle in removing these chrome trim tubes...because they were oxidized solidly in place.

    Normally, spring pressure holds these. It's possible that your springs are d.o.a....or that the assembly isn't fully seated. First step is loosening the pinch bolts in the bottom tree, removing the caps on the fork legs, then extracting the fork legs from the lower tree. You'll need a pair of new fork seals and a bottle of fork oil, I'd start with 15W. The seals are retained with internal snaprings. Once those have been removed, the seals can be pulled using a seal pick...or...using the lower fork leg as a slide hammer. If you use the latter method, wrap the leg with an old towel, to avoid spatter-painting your shop.

    Most of the rebuild consists of thoroughly cleaning the fork internals. You will find a goodly amount of abrasive dirt in there. Metalfinishing, polishing, brushing & clearcoating the lower fork legs is far easier whilst they are apart.

    Reassebly is even easier than teardown. The new seals can be pressed most of the way in using thumb pressure. A length of appropriate-diameter tubing can be used as a seal driver, to seat them fully. Refill with 3.5oz of fork oil, then install the cap and test fork action. If you can bottom-out the fork leg (sans spring) add another 5cc of oil and retest. Repeat this process until you find the point where you're right on the ragged edge between being able to bottom-out the fork leg and hydrolock. That'll firm-up fork action and deliver a ride quality that's better than all of the cheap Chinese aftermarket forks out there, at present. Note the total fill quantity of the first fork, then you can simply pour the same amount in the second side, no trial and error required.
     
  4. Dennis McDonaugh

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    Thanks for the tutorial. I'll eventually address this issue once I make sure the motor and transmission is in good working order.
     
  5. scooter

    scooter Well-Known Member

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    A tool I keep around to tap those chrome rings off. Home Depot pipe hanger and a file where the two halves meet such that they just catch the lip. Something to tap on when and if you want to remove them. Some can be tuff others easy 3247757B-A19B-47E8-BC7F-46DC38CAE4AE.jpeg
     
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