Removing a tight freewheel cog
 

After years of using a variety of makeshift clamping methods when dismantling freewheels , I finally found a nice old Suntour freewheel vise at a reasonable price. I clamped a Suntour Perfect into it (they're pretty much the only freewheels I use these days), tightened the assembl into my bench vise, and promptly broke both of my Park chain whips in trying to remove the outermost 14-tooth cog.


I had lubed the outermost cog with PB Blaster over the course of several days, as I always do. It evidently didn't help.


I have four questions for those with more experience in this area than I have:


1. What's the best way to repair a busted link on a chain whip?


2. Is there a more rugged chain whip on the market than the Park version?


3. Are some freewheels just impossible? After breaking a couple of chain whips, is it time to just throw the freewheel into the scrap metal barrel? There's nothing special about this one, really, though I would like to salvage the 6-speed spacers for re-use if I can. It also has some cogs in useful sizes, but it's not as if Suntour cogs are hard to come by.


4. Any hints on technique? After breaking the second chain whip it occurred to me that instead of just giving a mighty yank, I might have done better to put a long cheater bar on the chain whip handle and apply slower, steadier pressure instead. Would that have been more likely to work? Or is there some other method that, in my innocence, I don't know about?

I was also thinking that a cheater bar would give you optimum leverage, but if the weak point is still the chain whip, it probably wouldn't have made a difference. Perhaps there's a way to fashion a beefier chain whip (and, fwiw, my Park chain whip broke in the same way).

You might try a PM to Pastorbob, or he hopefully will see this thread. I have nothing beyond what you have tried, best of luck on finding an answer to your issue.

Bill

There was another thread about stubborn cogs, maybe 3-4 years ago. Depending on what you are willing to sacrifice vs. trying to save, there are some tactical to nuclear options. In one case, I used a cutoff wheel on a dremel tool to cut through the stuck cog. My preferred method these days is heat, e.g. from a propane torch, used judiciously so as not to compromise the heat treat of the cog being heated. Don't worry about coking the oil/grease inside the freewheel; that can be cleaned up, assuming you are willing to take the freewheel to bits afterward.

Using the principle that misery loves company, I'll say that I'm in the same situation on a few SunTour Winner freewheels. I've got cheater bars attached to my non-Park chainwhips, applied PB Blaster, waited weeks, and still can't get the dang small cogs off of the body.

Fortunately, it falls into the category of "problems that can be put off indefinitely", so that's what I've done. I'll be watching to see what other ideas come up.


Steve in Peoria

My setup is a Bicycle Research freewheel vise bolted to the wall at about belly button height (for max leverage) then a 3-ft cheater bar and put all my weight on it slowly. I have not broken my (old Nashbar) chain whip, but have broken a few cog teeth. Sounds like the chain whip is your weak link.

I've always had problems disassembling freewheels off of the wheel, with breaking the chain whip or the vice, as described above - seemed I couldn't apply straight force.

All the problems went away when I started to disassemble the freewheel while on a wheel - seems I could apply straight force down on both chain whips and have not found one I couldn't crack this way

.
...I hope I have enough old freewheels that I never have to do this again, because it was always a PIA. Having said that, I will repeat once more here that a 50/50 mix of acetone from the paint dept at Home Depot and ATF from the auto parts store works significantly better than PB Blaster as a penetrating oil on difficult to impossible jobs. It even works better than CRC Freeze Off, which works pretty well (also better than PB Blaster).

On the chain whip thing, have you tried making one out of bar stock and a (fatter) track chain ? That would be my next project if I were gonna do freewheels again. I think you'll still be able to get it to grab the outermost cog (but I haven't tried it). You can make the lever arm as long as you want this way. Use bar tape or something similar for the grip ends.

Chain whips can be repaired with regular pieces of chain, there's nothing magical about them. Back in the day we made our chain whips...I had pairs for each size chain.

Its all about proper leverage....get them lined up a little less than 180 degrees apart and apply ample force.

I like that idea.


I repaired both chain whips with a replacement roller-chain link from the hardware store. It's for thicker half-inch pitch chain so is a little awkward but works fine. I can't figure out how one would install a standard chain link, since the handle of the chain whip would interfere with the positioning of the chain tool.


Oddly, once I carefully applied the repaired chain whip to the same freewheel, the cog came right off. I have no idea why. Maybe that penetrating oil did its best work in that last 12 hours? That seems unlikely. Could I possibly have been turning the cog clockwise the first time? It's possible--I've done stupider things before now, and no doubt will again.

Not entirely stupid -- sometimes it helps to reverse direction to break a stuck part free. :thumb: