Removing chainring bolts - cut to the chase and drill them out?
 

Hi all, I need to replace my chainring and don't have the tool for holding the slotted nut stationary. Many report that the tool is marginal and the bolts get trashed in the process anyhow. Screwdrivers, "dimes in visegrips", and other hacks have never worked for me. Anyone have a trick I should try before I reach for the drill?

I suppose it may be a dumb thing to ask, but do you have replacement bolts? Because if you have, then drill, if not, don't. Also, drill only if you believe you know what you are doing. I think the bolts material, at least on my older bike, is soft, the slotted kind on the inside side.

On newer bike, when I had them removed a while ago, they felt fairly light, almost like made from aluminum. But those were of newer kind, with hex wrench on both sides.

The first thing is to try the Allen Wrench without the tool.

If the chainring is tight, then you may well be able to break the bolts loose without the special tool.

I usually get slippage if the bolts or spacers are sized wrong, and don't tighten properly.

I've used the tips of a small pair of needle nose pliers as a spanner to hold the nut's slots and keep it from turning while removing a chainring bolt.

I took a copper pipe and cut one end of it in half longitudinally. I then flattened it out and ground and bent the shape needed for the keeper. It worked but it really only held the slotted nut in place for removal and placement.

Latter it was worth the wait to get a Park Tool CNW-2. But then again, it really only held the slotted nut in place for removal and placement.

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...you can make a tool out of a sacrificial screwdriver, grinding/filing the tip to match the end of the purpose built tool. But I've never had much trouble using the tool, as sold, the proper sized hex key on the other side, and a liberal amount of ATF/acetone mix. I usually end up doing this operation sitting down at the kitchen table, which has tiles on top, over which I place some newspaper. That way you can kind of push down on the chainring tool on the bottom, using the hex key on the top.

I am pretty lazy and use an impact driver on those chainring bolts. They come apart pretty easily that way. Smiles, MH

The drill is sounding pretty good...:lol:

...just so you know before you start, if the drill bit gets locked in there and the bolt as a unit starts spinning, there's no way to hold it steady after you've drilled out the hexagonal socket in the top bolt portion. Which is an excellent reason not to do it that way.

This works really well. The bigger the handle on the screwdriver the better.

I have both the Park and Shimano chainring nut tool and they both equally suck. For some reason, the 90 degree bend in the tool makes it hard get a good interface with the bit. The tendency is to hold the toll against the chainring when using, and the tool angle is no longer 90 degree to the nut. Once you start rounding the slot on the softer aluminum nuts, it gets hard to get good purchase on the slot.

The screwdriver type nut wrenches seem to be better. But you might have to remove the crank to use. I guess one advantage of the Park style tool is it’s easy to remove the chainring with cranks still in the bottom bracket.

I believe I replaced the aluminum bolt and nut with steel. I’ll take the weight penalty if it removes the frustration of that aluminum nut.

Never really had an issue using the correct chainring bolt tool and a quality hex wrench then I can just replace with some hex bolts instead. I will admit it might not be the best tool but it works. The only time I think I had trouble was recently when a Torx bolt got stripped on a Shimano crankset but we got it out without too much fuss.

The first port of call should never be out and out destruction if that is the case, take your bike to a professional and have them do it. Destruction and heavy power tools should be a last option for a bike.

And after you've spun that nut a few times, it will have polished/enlarged the hole in the crankset and your replacement nut is unlikely to lock itself into place. (I love cranksets where the nut seats simply tightening the bolt. Need to get it out? Back off the bolt slightly and give it a gentle tap with a hammer.)

Might be a reason to avoid the impact wrench.

Get a tool. I don’t care for the cheap Park version. But you can get a decent Shimano or 3rd party.

Chainring bolts will probably cost as much as the correct tool and if you mess up the crank, the cost could be as high as getting a VAR chainring bolt tool.

The slotted nuts can be a pain, but I have never cheapened out and tried a dime or some makeshift tool that was not well thought out; especially with a triple.

John

OK - I ordered the Simano tool and some new bolts. Appreciate all the help!

Performance used to sell a commercial version of this as a Spin Doctor" house brand tool. It was just a wide blade screwdriver with the edges of the blade cut back leaving a central locating pin. It was a lot stronger than the flat sheet-metal tools.

Also my home-made copper tool, and my beat up wood chisel tool... In frustration I took a crank over to a now sorely missed, local machinist for ideas on how to proceed. His procedure was odd but remembered. He asked if my crank had been soaked with PB Blaster. Yes, several days... of course. He then took a can of Liquid Air for cleaning PC keyboards and turned it upside down and sprayed (trifloroethane) over all the bolts liberally till ice from garage air condensation was forming on the crank. After the crank warmed up he used my Park tool nut wrench to ease the bolts off the crank.

So what was it, the PB Blaster, the chill, the wrench, or the meticulous slow practiced method of a real Machinist?

I just swapped the chain ring (44T to 40T) on my wife's Electra Loft 7D this morning, and I was able to loosen all chain ring bolts without a chain ring nut tool, even though a basic one is built into the end of my Pedro Chain checker.

Chain Checker Plus II » Pedro's NA (pedros.com)

...thermal shock is often used on stuck threaded fittings. There's even a commercial product for this that combines a coolant and a penetrant, called Freeze Off. It's sold in auto parts places.

All for thermal shock. I had to use my butane cooking torch to uninstall the cheap pedals that were originally mounted on my hybrid bike.

My experience has been that the tool works 100% of the time. It's a cheap little piece of sheet metal, but aside from that I don't know what problem people have with it. You only need it to grip the chainring nut flats for an instant when you break the bolt loose. THen you can generally hold the nut still with one finger while you finish unscrewing.

THE SOLUTION to difficult chainring bolt removals is selective lubrication - first, wipe off any oils or greases or contamination from the outside of the nut (where the nut meets the chainring or cranks), then add a small amount of grease to the threads of the chainring bolts, but on no other surface. IF only the threads are lubricated, and the surface of the chainring nut that mates with the chainring is dry, the friction of the nut against the chainring will be much higher than the friction of the bolt threads against the nut threads and the nut will generally hold itself in place when you tighten or loosen the bolt.

Another option for when you get the bolts off is to find a set of chainring bolts with a nut that accepts a hex head instead of the split screwdriver tool. The strategy of differential lubrication is still effective, but it's much more likely you'll have an allen key handy than the chainring spanner when you are working on your bike.

Just to circle back, I got the Shimano tool and it worked OK. I used a C-clamp to hold it in place. Still one of my least favorite wrench jobs.

Thanks again for the suggestions!

The best chainring bolt tool: Cyclus 729996.
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5 interchangeable tips for: Campy, Miche, Truvavtiv, Shimano, and Sugino.
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