Cannot remove chainring lockring from Ashtabula crank
 

Hello,

I am restoring a 1973 Schwinn Varsity. I have the bike completely disassembled except for the crank. I took off the pedals, pulled the crank, unscrewed the chain guard and large chainring, but I cannot remove the lock ring that holds the small chainring in place. I have been applying Liquid Wrench penetrating oil to it every day for a week, but I can't get it off. I am using a large pair of locking pliers to try and remove it.

What can I do besides taking it to my LBS and getting them to remove it with their special tools?

You need more leverage than a pair of puny locking pliers. Get a 15 inch adjustable wrench or a good pipe wrench or use a strong, well mounted vise, using the crank arms as your "wrench." If it does not have flats just use a hammer and flat punch.

The problem with using locking pliers is that you're flexing the ring tighetr against the shaft as you try to turn it. If you have a piece of square key stock or similar You can put it into one of the notches so the pliers have a purchase and allow you to torque without squeezing s hard.

Or do as most old timers do, and use a dull chisel and drive it off with a hammer.

BTW- make sure you're turning the ring in the right direction, and not simply tightening it.

If you are working on the locknut that holds the chain-ring assembly to the crank it's Left-hand thread.

As ever, Saint Sheldon: "To disassemble a one-piece crank, start by removing the left pedal (turn it clockwise to unscrew it--everything on the left side of a one-piece crank is left (reverse) threaded.)"

http://sheldonbrown.com/opc.html

-Bandera

The lock ring still has the flats. I tried using a pipe wrench but the lock ring is so thin that the wrench can't get a very good grip on it. I tried using a vise, but when I push/pull on the crank arms all that I end up accomplishing is getting the crank to pop out of the vise.

How would I go about using a hammer and flat punch? Is the lock ring right or left-hand threaded? (can't remember right now)

If memory serves, it has a RH thread, but you can confirm just by looking at the exposed threads beyond the ring. If the lock ring is hex shaped, the best option is to trap an open end wrench against it with a stack of spacers (cut lengths of plastic pipe, or bicycle headset spacers, and the left hand cone, then turn. If it's a round, notched ring, set the chisel in a notch and drive it with a hammer. Note the chisel should have a dull 90° point so it drives, but doesn't cut the ring.

If it's hex, and you want to use the vise, set the crank as close to across the jaws as possible (dictated by the nut) and turn using both arms so there's less tendency to cam out of the vise. An long cheater bar slipped over the crank arm, increases the ratio of torque to linear force, reducing the tendency to hop put of the vice.

The locknut that holds the chainwheel is always a right-hand thread, as it is on the right side.

You need a better vise, like a machinist's vise whose jaws will stay parallel when tightened, though at this point you may have damaged the flats enough that it won't work. The LBS may or may not have a wrench that will fit the locknut - most would use a vise or large adjustable wrench. The hammer and flat punch was only if the locknut had notches instead of flats.

The two flats (there were only two to begin with, the rest of the ring is circular) are still in good shape. The vise I have is very old, it belonged to my great-grandfather. Maybe that's why it won't hold the lock ring in there very straight.

I think I will try visiting the LBS. If they can get the lock ring off, then I am good and can finish the rest of the work on my bike.

Thanks for the help.

That "lock ring" is actually the cone for the RH bearing. The flats are 43mm apart, so if using an adjustable wrench you'll need a big 15" example. A remake of the official Schwinn wrench used to remove them can be seen here. Once the wrench is positioned, a whack on the end with a hammer usually does the job. A good securely-mounted vise is probably the best tool for really stubborn ones.

Wow that's really cool. Maybe I'll have to get one for future use. Thanks

That is the tool I referred to before when I said the LBS may or may not have one. Once you get that locknut/cone off once and put a little grease or anti-seize to it you should not have such a problem. But if you want to pop the $20 go ahead. Remember to still pop the crank in a vise. BTW we never determined why you are removing it - is the cone worn or the chainring being replaced?

The chainrings are being replaced. I bought the bike for $8 at the Salvation Army store (I could't resist). I should start a thread in the Classic/Vintage section on my restoration efforts. I am going to convert the bike to a single speed because the derailleurs are rusted solid. I may reuse the small chainring because it's still in decent shape.

Here is a pic of what I am working with. Thank you all for your help.
http://bikeforums.net/attachment.php...hmentid=333152

Update: I took the cranks to the LBS. They couldn't remove it using the special wrench and a vise either. The guy suggested that I try using a blowtorch. I thought there would be one at my parent's house, but they don't have one either. I'll have to take it back to the shop and let them use their torch. I'll have to leave the cranks there overnight. They also had replacement cranks that I could get for $25, but I'd like to keep the original cranks.

Heat might help, but before you go nuts, do you need the nut (cone) or do you have a spare on another crank.

If you don't need the cone (nut) and only want to salvage the crank or chainring, then you can crack it off by grinding into it fairly deep, and using a chisel to fracture it (unless it decides to spin off.)

Wear real eye protection (eyeglasses aren't enough) because small chips may fly back when it shatters.

Thanks. I definitely want to salvage the crank, and would prefer to salvage the chainring (it's still in decent shape). I don't have a grinder or anything else that I could use to cut the cone off. I could use a hacksaw I guess I'll have to get a replacement cone if I can't get it off. Maybe the LBS will have extras.

The little voice inside my head wants to remind you that OPCs and their associated BBs are extremely cheap....

I ended up getting a new crank and BB. Thanks for the help.

I'm pretty much basically psychic.