How to remove lockring on very old (French) chainring
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Hi,
I am overhauling a very old french bike, and really want to take absolutely everything apart. The chainring is attached via a lockring as can be seen in the photo below; http://bikeforums.net/attachment.php...hmentid=334932 -- Do I remove the lockring anti-clockwise? -- What is the best tool to try and remove it? it has too large a circumference for any of my lockring spanners, I am using Hozan C-203 Lockring Pliers but after several days and lots of WD40, I cant get the lockring off (I think it did move it a bit (anti-clockwise), but it seized up tight again (hence the question about clockwise/anti-clockwise). Any suggestions? |
It should come off counter clockwise . WD-40 not a very good oil for this , try something like PB Blaster in it place and it might take a few days for it to work in . If you have a vise use it to hold the crank arm as you work on the locking ring .
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That is a puzzle, is the chainring threaded on ? Like a track hub, or is the lock ring like a ashtabula crank? Perhaps clamping lockring in a vice using soft jaws, then use a cheater bar over crank arm to loosen lock ring . Cottered cranks are fun !
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"try something like PB Blaster" or Kroil.
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The French did not even make fixed cups reverse thread, so I'm betting it's normal. Unless you are planning to chrome the chainwheel I don't see any reason to disassemble. Also, even if the right size a lockring tool is generally not appropriate for something that old and frozen on. I suggest you clamp the arm in a vise (horizontally) and take a hammer and flat punch to the lockring notches after treating with PB Blaster.
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Thanks for the replies, as per normal, the products recommended (PB and Kroil) are not available in France. I can get an 8oz can of Kroil from USA for 11$ plus 55$ postage, and I may just do that, but I have just been reading a bunch of threads saying auto transmission fluid mixed with Acetone is better than all the commercial penetrating oils, so (presuming I can get acetone here) I might try that first;
**Machinist's Workshop magazine tested penetrants for break out torque on** **rusted nuts with significant results!** **They arranged a subjective test of all the popular penetrants with the** **control being the torque required to remove the nut from a** **"scientifically rusted" environment.** ***Penetrating oil ...... Average load*** **None ....................... 516 pounds** **WD-40 ................... 238 pounds** **PB Blaster .............. 214 pounds** **Liquid Wrench ..... 127 pounds** **Kano Kroil ............. 106 pounds** **ATF-Acetone mix....53 pounds** **The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic** **transmission fluid and acetone. Note the "home brew" was better than any** **commercial product in this one particular test. Our local machinist** **group mixed up a batch and we all now use it with equally good results. ** **Note also that "Liquid Wrench" is about as good as "Kroil" for about 20%** **of the price.** |
You can also try a propane torch, though preferably after removing most of anything you've used to loosen things up. I still recommend just leaving it.
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Geez. I'd just leave it alone. What do you hope to gain by removing it? That's a lovely crank and I'd hate to ruin it with ham-handed attempts to separate the ring from the arm.
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"Geez. I'd just leave it alone. What do you hope to gain by removing it?"
Thats a very good point, and I agree its not necessary to remove it,,, but... -- its a learning experience. I would like to know I can remove these if I need to (or not I suppose) -- I want the satisfaction of knowing I have *completely* stripped the bike and every part is reassembled with grease or oil, and can be serviced if needed. -- If I can find a smaller chainring, I would love to lower the gearing (its VERY hilly round here (French Pyrenees) -- The photo is actually of a practice chainring/crank. I bought a whole box of rusty parts on ebay for 20euros and there were a couple of these in there. I am learning on one of these, and if I think I can remove the one mounted on the bike I am restoring without buggering it up, then I will have a go. Thanks, I appreciate all the help and suggestions. I have benn working on it with the Hozan C-203's while it is in a vice (with soft jaws fitted). I will see if I can fix the chain-ring and rotate the crank, and if not will try to fix the crank and hammer at the lockring with a punch. I will wait until I have acquired and mixed up some ATP/Acetone first though. Cheers, Bruce. |
Just in case this ever helps anyone... I got the lockring off.
I hammered it counter-clockwise a bunch with a punch and it moved an inch or 2 and then stopped. I then had the good fortune of meeting someone local who really knows vintage french bikes, and he showed me that they are reverse-threaded. I got home, and was able to remove it clockwise with just the Hozan lockring pliers. (it had been treated for a few days with my homemade penetrating oil (see above), not sure if that helped; but turning it in the correct direction certainly did). Lesson learned :) |
In my experience all French chain wheel lock rings are reverse threaded, so punch clockwise to remove.
There are very few [fine] threads on the lock ring and if you wire brush around the seating and the outer surface where the threads are; then liberally apply paraffin, this will do the trick. There is no need to use a vice. Even better if you use a short length of 6mm hard brass rod as a punch, with a hammer of course ! |
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