Introduction: Stupid Wrench Tricks

Picture of Stupid Wrench Tricks

Need a large wrench to get the bottom bracket off a bike? Disappointed by the assortment of not-large-enough wrenches in your bike took kit? Me too. Here I use two wrenches in an ad-hoc fashion to do the job of a much larger one.

Step 1: Identify the Problem

Picture of Identify the Problem

So here we have a bike bottom bracket that I want to take apart. However, the lack of standardization means that none of my bike tools are able to get it off. I could have waited a few hours till the shop at work opened, and snagged a larger wench from there, but I was on a mission.

I used the crescent wrench to grab on to the edge of the nut, and tightened it onto the edge so that it wouldn't wander off. I set it up so the handle crosses the rotation axis of nut. This will let me torque the crescent wrench with a large open wrench in the next step.

This has the potential to mess up the interior surface of the nut. It didn't and I didn't care because I was just trying to take it apart, but your mileage may vary.

Quick disclaimer: Every shop safety guide ever published includes "Use the right tool for the job," and most accidents are caused by using the wrong tool, so if you can use the right tool you should. While doing this I was very aware of the risks, and tried not to be any dumber than I was already being.

Step 2: Add Another Wrench.

Picture of Add Another Wrench.

Now that the crescent wrench is all snug, take a handy massive open wrench and use it to rotate the crescent wrench. Neither of these are designed to do this, but I didn't run into any issues with slippage. As long as the load is perpendicular to the axis of rotation it is a stable arrangement. If you start angling the open wrench up and down you will likely slip and bash the dickens out of your hand. Using a long wrench also give massive mechanical advantage: the nut came right out.

Step 3: Fin.

Picture of Fin.

And now the nut is out. The nasty goopy grease they packed the bracket with kept the threads all nice. Too bad it couldn't save the rest of the bike.

Hypothetically you could apply this method to other stuff. I can't think of any applications offhand, but I'm sure there are others.

Comments

lbrewer42 (author)2011-07-21

Actually I think the BEST trick shown here is that your are using your head instead of throwing money at the problem. You would make a good politician!

Seriously, an eye for practical innovation is a very useful thing. It is too bad so much of our society has been dumbed down to thinking that if the "right" professional is not the one "changing my light bulb" (add anything here) - then the job can't be done properly.

My son was taught in one of his school classes that you should NEVER try to do anything to your own car except maybe change the oil - otherwise you could mess up the whole thing - always be willing to pay a professional.

Yeah right! Professionals have their places - but a lot of what goes wrong simply can be taken care of with elbow grease and - like this good instructable - some innovative use of logic.

Steverino (author)2008-03-21

Isn't a bottom bracket a sealed cartridge type assembly with splined ends?

jptrsn (author)Steverino2010-02-26

Some low-end bikes still have the cup and cone type bottom bracket, which is serviceable. Most of the high end bikes use cartridge units that require a bottom-bracket tool to remove.

Bandaids (author)2010-01-19

Give me a week with it id have it back together in no time.

Alecw35 (author)2009-04-22

sometimes the Bottom bracket cup will be stuck in there as that frame is alloy, and the cup is steel. the dissimilar metals will fuse together.

canida (author)2009-01-20

This makes me happy.

gbosbiker (author)2008-03-20

well done. ive thought of something similar but this takes the cake. in your picture of the bike "scraps" quite bit of it could be saved. oh well. not my bike.

Yeah, I could have done better. In this case I was looking for parts I could use on my existing bike, and in terms of parts I need vs parts I could salvage there wasn't much.

excellent point. i only saw stuff like the suspension and stuff. those things could be sold on ebay or at a local bike store. you could get a decent amount of money for them. thats the only reason i said that.

PhotoPeng (author)2008-03-19

That's only 1 trick.
Here is a couple more:

Warning: May void warranty.

You can use a 2nd wrench(not crescent ) bigger than the first, to give you more torque on a bolt/nut. (e.g. 1/2 closed end on a bolt, and closed end of a 9/16 interlocked on the open end of the 1/2) Force x Length = Torque

You can use some metric and SAE socket/wrench sizes interchangeably .
I'm not taking credit for this chart, I found it somewhere else.
5/16 & 8mm
7/16 & 11mm
5/8 & 16mm
3/4 & 19mm
7/8 & 22mm
15/16 & 24mm
1 1/16 & 27mm
1 1/4 & 32mm

When tools are manufactured, they aren't -exactly- perfect. It's a rough chart to come 'close enough' without rounding heads.

PhotoPeng (author)PhotoPeng2008-03-19

In a tight space you can use a 8mm or 9mm wrench on a quick connect screw driver heads.

GorillazMiko (author)2008-03-19

How are these stupid?

I feel that while useful, they are stupid in that one could mess themselves up doing this. Also it's not terribly complicated, and thus, "stupid" in that sense as well. But really, I called it "stupid wrench tricks" because it makes a better title then "Improper ways to use two wrenches." :)

Shifrin (author)GorillazMiko2008-03-19

SUFFERING SUKATASH

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