Road Bike, Cycling Forums banner
1 - 19 of 19 Posts

·
a real member's member
Joined
·
3,880 Posts
Discussion Starter · #1 ·
i don't have the proper tool (if there is one) to hold the nut in place while i try to loosen a stuck chainring bolt. i was down to one last pesky bolt in this crank i bought on ebay, and i was quickly losing patience.

i sprayed it with freeze-off and went through my collection of makeshift tools, trying to keep the nut still enough to loosen the bolt. usually a coin (dime) in a pair of vise-grips is my go-to tool for this, but it just wasn't happening. a bottle opener actually almost worked. still, the bolt and nut were just spinning 'round and 'round, joined together in rusty bliss.

so i got out my $10 dremel tool and removed just enough of the back of the bolt to allow the bottle opener to get a grip on the two flats of the nut. and it worked! joy! take that ebay seller! ha ha!

Gear Bicycle drivetrain part Bicycle part Tool Tan

it's the small victories that make it all worthwhile...
 

·
a real member's member
Joined
·
3,880 Posts
Discussion Starter · #3 ·
i think i should just make a proper tool ... by taking the dremel to a coin ... or the bottle opener.

i mean ... who has 'the proper tool' for this problem?

there are a few tools i don't have, where i improvise whatever works. and it usually does!
 

·
Doesn't like subtitles
Joined
·
3,808 Posts
Well played, sir!

I have the tiny little two pronged Campy tool, but for being the proper tool, it doesn't even work that well. You have to press the prongs in the notch and then the tool is so small it's hard to hold on to it for a serious torque application.
 

·
Registered
Joined
·
14,713 Posts
Well played, sir!

I have the tiny little two pronged Campy tool, but for being the proper tool, it doesn't even work that well. You have to press the prongs in the notch and then the tool is so small it's hard to hold on to it for a serious torque application.
True. Last time I changed a chainring, I took the crank off the bike and clamped the tool and crank in bench vise, both keeping the tool in place and firmly preventing it from moving. It was no problem then to torque the bolt. Fortunately I don't change rings too often.

i don't have the proper tool (if there is one)
Of course there is one. Several, actually. The Park version costs about four bucks.
 

·
a real member's member
Joined
·
3,880 Posts
Discussion Starter · #7 ·
The Park version costs about four bucks.
[in my johnny carson voice] i did not know that.

i'm gonna continue to use my dime in vise-grips method. maybe i'll spring for a real tool when i cross this one again. in some 40 builds, it's been a problem twice.
 

·
Registered
Joined
·
11,474 Posts
Sometimes you can catch the nut napping and tighten to specs without that tool. Tighten the bolt until the nut just begins to turn on you, then stop. Get a good grip on the Allen wrench and turn it clockwise with a hard jerk. Speed is the key, not force. Before the nut has realized what's going on, it's so tight onto its seat that it won't turn any more. I have no idea how this actually works, but it does many times.
 

·
Registered
Joined
·
11,474 Posts
The key is to not say what you're going to do before doing it. :wink5:
Exactly, you want the element of surprise.

Actually, I was acutely aware of the fact that I was anthropomorphizing chainring nuts. I thought it would illustrate the procedure neatly. Now everyone thinks I'm nuts. I knew better, should have stuck to dry and boring tech lingo. :D
 

·
Registered
Joined
·
153 Posts
Exactly, you want the element of surprise.

Actually, I was acutely aware of the fact that I was anthropomorphizing chainring nuts. I thought it would illustrate the procedure neatly. Now everyone thinks I'm nuts. I knew better, should have stuck to dry and boring tech lingo. :D
Not just nuts, but chainring nuts. :7:

The proper chainring nut tool does suck, but works better than the chisel that I dremeled down. I basically just ruined the chisel and ended up buying the tool.
 

·
Registered
Joined
·
14,713 Posts
Sometimes you can catch the nut napping and tighten to specs without that tool. Tighten the bolt until the nut just begins to turn on you, then stop. Get a good grip on the Allen wrench and turn it clockwise with a hard jerk. Speed is the key, not force. Before the nut has realized what's going on, it's so tight onto its seat that it won't turn any more. I have no idea how this actually works, but it does many times.
That does work, at least sometimes. The reverse procedure for removing a bolt does not work, IME. I.e., you can't get it to loosen by sneaking up on it with a quick jerk on the wrench; you have to hold the nut somehow.
 

·
Registered
Joined
·
14,713 Posts
Use chemical to sedate it. If my memory serves, that chemical is called wd... something. View attachment 316336
The problem is, the lubricant is as likely (or more) to make its way into the interface between the nut and its seat as into the interface between the threads. This makes the problem worse.

BTW, wim, I think the explanation may not be in the mysterious psychology of metal, but in something called "stiction." I think. Maybe.
 

·
Registered
Joined
·
11,474 Posts
BTW, wim, I think the explanation may not be in the mysterious psychology of metal, but in something called "stiction." I think. Maybe.
I read up on it and stiction is part of it, but it's about overcoming it. When the bolt is turned slowly, the nut behind it matches its low rotational acceleration and turns along with the bolt.

When the bolt is turned with a quick jerk, the nut needs to match that much higher acceleration to move along with the bolt. But there's not enough frictional force ('stiction') available between the bolt and the nut to drag the nut along, so it lags behind. And 'lagging behind' means that the bolt can turn into the nut, tightening the connection.

The principle is identical to, believe it or not, jerking a tablecloth out from under a place setting without upsetting it. The place setting 'lags behind.'
 

·
Registered
Joined
·
3,285 Posts
The principle is identical to, believe it or not, jerking a tablecloth out from under a place setting without upsetting it. The place setting 'lags behind.'
I guess the same principal applies to hair waxing? After all, we are talking about removing something... :idea:
 
1 - 19 of 19 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top