Objective: Remove a stuck Suntour freewheel without having access to the original tool.
A while back, I bought an old-school steel road bike that came with Suntour components including a freewheel.
The freewheel was new. However, eventually, the chain got slack when backpedaling and coasting (read more), and after removing the wheel, I concluded that the source of the problem was the sticky freewheel.
So, I had to unmount the freewheel to degrease and re-grease it but didn’t have the right tool for the job.
The older Suntour models need a freewheel removal tool with 2 notches. The later models require a 4-notch tool.
I checked the local bike shop sites, and one of them allegedly had both tools, but when I called it turned out that they had only a 2-notch model. In the reviews, many people were criticizing the tool for being made of softer material.
The only solution was to make my own or order the Park Tool version online and wait for 1-3 weeks to get a unit.
In hindsight, the process seems simple, but I had a few annoying problems that I could have prevented with better planning.
Here’s how you can make your own Suntour freewheel removal tool for less than 10 bucks.
Note: The method described below is for wheels with a quick-release skewer.
- 17mm socket
- Metal file or a rotary tool (Both work but the rotary tool is faster)
- Hacksaw (not mandatory but helpful)
- 8mm nut
- 8mm socket
- Washer (the size is custom and depends on the socket as I will explain later)
- A vise
Step 1: Filing
As you can already guess, I used the 17mm socket to make my own tool. I placed it on the freewheel and marked the 4 spots that had to be filed for the tool to fit in.
If you have a Suntour freewheel with 2 notches, mark the two spots that will stick out and file the rest.
I didn’t have a standard vise in my apartment and used my workbench as it had a cut for holding pipes.
I recommend first making 2 cuts to specify the width of the spot that you will file.
Then, it’s time to file.
My socket cost me USD 2, but it was still made of quality Chromoly steel, and it took me quite a while to file the spots.
I even went to the hardware store and bought a new metal file as my old one was too worn.
Eventually, I reached a shape that would slide into the freewheel.
Tip: As you do your filing, put the tool periodically on the freewheel to see how off you are.
Step 2: Securing the Tool
The next step is very important.
In order for the tool to bite, it has to be secured to the freewheel. If it’s not, it will keep coming out, and every failed attempt will damage the teeth of the tool.
With a modern freewheel removal tool, this isn’t an issue because the tool goes pretty deep, but in the Suntour case, the connection is pretty shallow.
If you have an original removal tool such as the one made by Park Tool, you can secure it easily via the quick-release and then use a wrench to untighten the freewheel.
In our DIY version, however, this isn’t possible for two reasons:
- The socket is long and circular. Thus, you can’t use a regular wrench.
- The socket wrench has to go into the socket.
However, I came up with a successful workaround which goes as follows:
Wedge a washer into the socket to narrow the inner diameter. The washer has to be large enough for the quick-release skewer to pass through.
Add washers or a couple of large nuts to the side of the skewer with the lever on. The goal is to move the skewer further away and make space for the socket wrench.
Remove the nut end of the skewer.
Slide the skewer through the axle. Then put the removal tool and make sure it fits tightly.
Finally, with the help of a thin socket extension wrench tighten an 8mm nut onto the skewer until the tool/17mm socket is secured.
Then, insert the socket wrench into the socket. Ideally, at least 1/2 of the wrench’s end will slide into the socket. However, even less could be enough.
Step 3: Untighten the freewheel
With the tool secured, rotate the socket anti-clockwise.
If the freewheel is particularly tight, you will need to slide a long pipe onto the wrench and extend the leverage.
Alternatively, you could use a box end wrench as an extension.
Press down. If everything is fine, you will feel a partial untightening of the freewheel.
Then, untighten the nut holding the tool, re-insert the socket wrench and keep rotating it anti-clockwise.
When the freewheel gets really close to the locknut of the axle, slide it out.
Is a socket strong enough?
It is. In fact, it’s probably stronger than the regular removal tool because it’s made out of Chromoly steel. I have a regular removal tool for standard (non-Suntour) freewheels, and it is super soft in comparison.
Does a file really work?
A rotary tool such as a Dremel is better, but a file works too. I made two tools. One with a file and one with a cheap Dremel.
How important is it to secure the tool?
Honestly, it’s vital.
Here’s a funny story. I first made a tool by using just a regular metal file. I tried to untighten the freewheel without securing the tool but failed. I kept trying, but the freewheel wouldn’t move.
I concluded that I needed a better tool and bought a cheap rotary tool specifically for this task.
I made another tool, slightly better looking, but it failed too.
This is when I figured out a way to secure the tool to the freewheel.
When I did it, I was able to remove the wheel with both tools. Or in other words, my file tool was perfect. I just needed to secure it to the freewheel.
Do not skip this step. It’s essential.