How to Service a Freewheel

A while back Moe and I were talking about the freewheel on his Single Speed 29er. He mentioned that he was getting some dirt and grit in there and wanted to know how to service it. So after contacting our buddy Vince Rodarte of KHS Bicycles, he wrote a very interesting article that schooled me into learning how to service a freewheel.

“Ok, Class, please pay attention!

Mr. Policar! Mr. Policar! AHEM! MR. POLICAR!!!!!…… what would your mother say if I called her to tell her you got sent to the principals office because you can’t keep your hands off of Pricilla’s books??

Ok, well please pay attention!

You’ll need the following tools:

  • Pin Spanner
  • Small flat blade screw driver
  • Small shop hammer
  • Small Magnet (for catching run-away bearings)
  • Solvent (Clean Streak, or something similar)
  • Rags
  • Lube ( I prefer Phil Wood Tenacious Oil)
  • First, take a rag and wrap around the backside of the freewheel.
    Then, while holding the rear wheel with the freewheel facing up. Looking at the freewheel

    ACS Claws Freewheel from

    You’ll notice two pin holes. Using your pin spanner, spin this face cover counter clockwise.

    If it’s too tight use the small screwdriver as a punch and tap it with the hammer until it breaks loose.
    (at this point, your wheel should still be in the “drive side up? orientation)

    Open the face cover just enough to get the spray tube of your solvent (Clean Streak) inside. Spray to your hearts content to flush all the crap and old lube out of the freewheel.

    MAKE SURE YOU DON?T OPEN THE PLATE TOO MUCH, YOU COULD BLAST THE SMALL BEARINGS OUT WITH THE SOLVENT SPRAY!!! (in case this happens, use the magnet to find your bearings)

    Let the solvent evaporate out. Spin the freewheel to loosen anything up and re spray with solvent. Let the solvent evaporate again.

    Finally, use the Phil Wood drip oil and thoroughly lube the freewheel and snug up the face plate. Don’t worry about over tightening. There is a bottom out surface that the plate will contact before crushing the bearings.

    That’s it.

    NOW GO TO RECESS!!!!!!?

    Vincent P. Rodarte
    KHS & Free Agent Bicycles

    6 Replies to “How to Service a Freewheel”

    1. You guys are reading my mind! I’ve had a clunky, knocking noise coming from mine(at least i think it is) for about a week or two. Is this a sign that its loose? Can I just use a hammer and a metal punch to loosen the freewheel instead of a spanner?

      This is actually on my Redline 925.

    2. d’oh…maybe i should read the whole article. Guess i can use a hammer and a punch.

      Still wondering if the knocking is my freewheel though.

    3. The clunking is the nature of the beast on a lot of freewheels (ACS, ACS Claws, Shimano MX freewheels). It doesn’t mean anything…it’s only annoying.

      Whatever you do, do NOT remove the face cover (upper cone)completely. Putting all those tiny bearings back (there is like a zillion of ’em in there!) and compressing the springs and pawls to get it all back together is an exercise in frustration. Ask me how I know!

    4. Thank very much guys. I was really worrying as the knocking was getting REALLY loud while going uphill, on one ride in particular. However, the noise is minimal now.

      GR that makes me feel a lot better. I can deal with noise, as long as I know it’s okay.

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