Advanced Sturmey Repair: Replacing Left Hand Ball Cups on Old AW and FW Hubs

 

This entry discusses a somewhat more advanced repair to older Sturmey Archer hubs: removal and replacement of the left (non-drive) side ratchet ring. This part is called the "left hand side ball cup" in the old diagrams (see above - part K517).  

Why would you want to do this? It allows you to save an older hub that has left (non-drive) side cup issues, replacing the ratchet ring and bearing cup as a unit. This work applies to older Sturmey Archer AW and FW hubs that have flatted ratchets. This is a good fix if you have a pre-war AW hub that needs a refresh, for example. In the early 1960s, the hubs switched to a press-in left hand ball cup. This article refers to the earlier hubs with threaded and flatted left hand ball cups.

There are two ways to replace the non-drive side ratchet ring and bearing cup. The first is if the hub is laced into a wheel, you can use the wheel and a heavy-duty vise to spin off the ratchet ring and cup from the hub shell. The second method is if the hub is not laced into a wheel, you can use the Gentleman Cyclist ball ring tool, heavy duty-vise, and a 15-inch adjustable wrench to spin off the non-drive ratchet ring and cup.

CAUTION: This a job for the "advanced" Sturmey Archer enthusiast because it requires some heavy-duty tools and an understanding of how the older AW or FW hub works.

 

You'll Need:

• Heavy-duty bench with a bolt-down vise.
• Propane Torch
• Loosening oil (I like Kano Kroil)
• 15-inch adjustable wrench (if hub is not laced into a wheel)
• Gentleman Cyclist ball ring tool (if hub is not laced into a wheel)

If the Hub is Laced into a Wheel:

• Using the Sturmey Archer hub instructions, remove the innards of the hub so that you are down to just the hub shell and the non-drive ratchet ring/cup (called the "left hand ball cup", part no. K517 in the diagram below). Fix the hub into the vise by tightening the jaws around the flats of the left hand ball cup.
  

 

•  Dribble some of your creeping oil inside the hub shell, focusing on the area where the left hand ball cup threads into the inner surface of the shell.
• Gradually and evenly heat the outside of the hub shell in the area where the left hand ball cup threads in. Warm that area until you start to see little bubbles in your oil inside the hub. Caution - do not overheat the oil, hub, or spokes.
  
• Let it cool. Repeat the cycle of oil, heat, and cool once or twice more.
• Using the wheel as leverage, spin the wheel clockwise (the left hand ball cup is left-hand threaded). If the left hand ball cup will not spin off, repeat the heat/oil/cool cycle again.
• Once the left hand ball cup is loosened, spin the wheel so that it frees from the left hand ball cup. Replace the left hand ball cup with a good cup by mounting the good cup into the vise and spinning the wheel counter clockwise until tight.
  

What if the Hub is Not Mounted into a Wheel?

If the hub is not mounted into a wheel, you'll also need the Gentleman Cyclist ball ring tool and a heavy-duty wrench. I like to use a 15-inch adjustable wrench.

• Remove the hub innards from the hub. Place the Gentleman Cyclist Ball Ring Tool into the vise as you would to mount a ball ring. 
• Put the hub shell into the vise, tightening the jaws around the flats on the left side ball cup (K517 in the diagrams above).
• Dribble your oil into the inside of the shell, focusing the oil on the threads where the left side ball cup joins the inside of the hub shell.
• Heat the outside of the hub shell using a propane torch evenly and gently around where the left hand ball cup threads in. Keep heating until you see little bubbles in the oil inside the hub. Let cool. Do not allow the oil to burn or smoke off.
  
• Repeat the oil/heat/cool cycle once or twice more.
  
• When sufficiently cool to handle (caution - hub may still be somewhat hot) mount a drive-side (right side) ball ring into the hub shell using the tool. [I assume that if you have this tool, you know how to use it to put in a drive side ball ring already.] This is part K60 in the diagrams above.
  
•  Now you should have a hub shell with a left hand ball cup on one side and a right hand ball cup on the other, but without anything else in it. The hub should be resting upside down - with the drive side ball ring in the Gentleman Cyclist Tool. The non-drive side ball ring flats should be facing upward.
• Attach your large adjustable wrench to the flats on the non-drive side cup which is facing upward. Make sure the notches of the drive side ball ring, which is facing downward, are firmly in the Gentleman Cyclist Tool.
• Begin to turn the wrench clockwise (the non-drive side ball ring is left hand threaded). Apply gradually more and more force until the ring gives and begins to spin off. 
• If the ring won't move even with great force, repeat the oil/heat/cool cycle for those inside threads as stated above.
• Once loose, spin off the non-drive side cup and replace with a good cup. It will thread in counter-clockwise because it is left hand threaded.

Photos:

 Below: an illustration of the oiling the hub. This hub shell is not in a wheel, and the innards have been removed. At this point all I have is the hub shell, the left side ball cup, and the right side ball cup in place. I have dribbled oil down the inside wall of the hub and into the joint between the left hand ball cup and the hub threads.

Below: here is the outside of what I have: hub shell with both the left ball cup and right ball cup mounted. The flats of the left side ball cup are gripped in the vise jaws.

 

 I then apply the torch evenly around the base of the shell, where the oil is sitting in the left ball cup threads. I heat until the oil bubbles, but stop before it burns or smokes out. I then let it cool, and that helps draw the oil down deeper into the threads.

Once sufficiently cool, the Gentleman Cyclist tool is mounted into the vise, and the hub shell is flipped over so that the right hand ball cup/ring connects firmly to the Gentleman Cyclist tool.

 

A large adjustable wrench is then applied to the flats on the left hand ball cup. It's left-hand threaded, meaning I turn the wrench clockwise to loosen.

Below - the left hand ball cup finally loosens up after several heat, cool cycles with the oil. I can now turn the left hand ball cup off and replace it.

 

Below- after removal of the left hand ball cup, you can see the shiny areas of thread where the oil penetrated. Lots of oil in those threads is a good thing. You get the most out of your effort when the oil fully works its way down.

Below are a couple of Sturmey hubs saved in just one weekend. One is a pre-war AW with 40 holes and the other a 1950 AW with 40 holes, both great hubs for vintage English bikes.