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Given that pedal threads are different on the left and right pedals: the right side pedal has a right-hand thread (removes counterclockwise, installs clockwise); the left side pedal has a left-hand thread (removes clockwise, installs counterclockwise), I often find myself trying to remember which way to turn the wrench to loosen a pedal.

Does anyone have a good-- preferably humorous and easy to remember-- mnemonic device to forever ingrain in my memory which pedal goes which way and keep me from over-tightening when I am trying to loosen?

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  • 2
    I usually pull-up my laptop and look at one of the numerous videos on youtube to get it right....
    – Chmouel Boudjnah
    Commented May 27, 2011 at 12:07
  • 2
    There can be additional confusion if you're using an Allen wrench on the inner side of the crank. So remember that all of the mnemonics assume you're using a pedal spanner.
    – amcnabb
    Commented Jul 26, 2013 at 17:35
  • Based on the number of answers I move that we declare the official answer to be a resounding NO.
    – jqning
    Commented Aug 9, 2015 at 2:01
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    Why is this so complicated?? You screw/unscrew the right-side pedal the same way you would any screw -- the "right" way. The left pedal is the opposite ("sinister", if you wish).
    – Daniel R Hicks
    Commented Aug 14, 2015 at 12:14
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    Kind of depends on your politics - right is right - left is wrong
    – paparazzo
    Commented Feb 12, 2016 at 15:55

28 Answers 28

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What could be simpler than remembering that the left-hand pedal has left-hand thread?

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    It helps that the right side is where the drivetrain is. The side with all the mechanical stuff is the one that got it "right". The oposite side, like lefties everywhere, is all alone and "backwards". (Apologies to lefties everywhere.)
    – Goodbye Stack Exchange
    Commented May 27, 2011 at 17:36
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    @NeilFein - There's a sinister tone to your comment. (Or was it intended to be a left-handed compliment?)
    – Daniel R Hicks
    Commented Dec 8, 2012 at 18:01
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    Sorry if it came across badly; that wasn't my intent, but I can see how that would be the case. It's a mnemonic that works, is all. I have no objection to deleting my comment if people find it offensive.
    – Goodbye Stack Exchange
    Commented Dec 8, 2012 at 20:08
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    For reference: I'm pretty sure Daniel was just enjoying some quality puns, and there's nothing in your comment to worry about.
    – Useless
    Commented Dec 11, 2012 at 16:12
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    @DanielRHicks You're a punny guy. Sinister is derived from the Latin "sinistra" which means "left-hand," and according to Dictionary.com can simply mean "left-handed." So it was clearly meant to be a left-handed compliment. :)
    – jimchristie ♦
    Commented Mar 17, 2013 at 4:01
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I don't worry about left hand or right hand thread. I remember that the chain always resists tightening the pedal. So I attach the spanner more or less opposite the crank and try to pedal backwards with it (to remove a pedal), or pedal forwards (to tighten a pedal).

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  • Thanks @moz! Even though this isn't a mnemonic, I like it a lot because it effectively explains why the pedals are threaded this way.
    – Zippy
    Commented May 31, 2011 at 11:51
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    This is how most shop mechanics remember it as well. Pedal backwards to remove the pedal, regardless of which side of the bike.
    – zenbike
    Commented Jul 23, 2011 at 5:27
  • @Zippy, it really is just a handy way to remember it. The real explanation for why the pedals are threaded this way is given in DanielRHick's answer.
    – amcnabb
    Commented Aug 17, 2012 at 18:15
  • When putting the bike on its head, things are reversed...remembering that the right side does it "right" and the left side "wrong" makes me remember that the right side is left when the bike is top down.
    – TheBlastOne
    Commented Jul 24, 2013 at 4:23
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Simple: To figure out which way something is threaded, figure out why it's threaded that way.

The reason for thread directions on rotating objects with lateral load

In general, the thread direction is NOT chosen so that friction from the rotating shaft will tend to tighten things. If that were the case, pedals would be left-hand threaded on the right side and vice-versa.

Rather, it has to do with precession. If you hold a pencil loosely in your left hand while you move the end of the pencil around in a circle with your right hand, the pencil will tend to rotate in a direction opposite of the direction you're rotating the end.

When you pedal a bike forward, the right pedal is moving in a counter-clockwise (or anti-clockwise, on the other side of the pond) direction, relative to the pedal shaft. This produces the counter-intuitive (anti-intuitive on the other side of the pond) effect of driving the pedal shaft in a clockwise direction -- rightie-tightie.

For the same reason, English-threaded bottom bracket cups have a LEFT HAND thread on the right side, and vice-versa. (The sneaky French and Italians just use Loctite and right-hand threads on both sides.)

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  • This all goes out the window on unicycles where people tend to pedal a lot in both directions, especially when doing trials and other things. You really have to check your pedals before every ride to ensure they haven't come loose. I wonder if fixed gear bikes have some of the same problems?
    – Kibbee
    Commented Jul 23, 2011 at 1:19
  • Fixed gear bikes (outside of a circus) aren't ridden backwards enough to be a problem. And with unicycles the direction would be at least 60-80% forward (assuming the seat is asymmetric so the cycle isn't mounted backwards).
    – Daniel R Hicks
    Commented Jul 23, 2011 at 11:01
  • I wasn't thinking about riding backwards, but more the backwards force, especially from those who ride without brakes.
    – Kibbee
    Commented Jul 23, 2011 at 15:47
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    Easy: To remember which way something is threaded, just figure out the effect of the precession.
    – Daniel R Hicks
    Commented Jul 24, 2011 at 20:06
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    See also this related explanation: physics.stackexchange.com/questions/6488/…
    – amcnabb
    Commented Aug 17, 2012 at 17:20
11

I remember which way to go by turning the pedal wrench toward the back of the bike because to undo the pedal, you have to go backward. To tighten the pedals, turn it toward the front because once you have the pedals on, you can go forward.

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    I always figure that when the bolt breaks you were probably turning it in the wrong direction.
    – Daniel R Hicks
    Commented Jul 22, 2011 at 21:12
  • @Daniel at that point you're swearing at yourself because you've already stripped the threads trying to pull your cranks off, and it only got worse when you tried to fix that with a tap. Time to get a new bike!
    – raabidfun
    Commented Jul 22, 2011 at 21:19
  • I could go into a long-winded discussion about how most people misunderstand the reason for threading left or right on a shaft, but it's late and I'm kinda tired.
    – Daniel R Hicks
    Commented Jul 22, 2011 at 21:24
  • @Daniel Doesn't it have something to do with pedaling direction and that you're pedaling forward, so you want the pedals to tighten forward and not loosen from friction?
    – raabidfun
    Commented Jul 22, 2011 at 21:27
  • and if you're really in MN, it's not even 5pm. If I am mistaken about the threading, I'd like to know.
    – raabidfun
    Commented Jul 22, 2011 at 21:29
11

I recently bought a bike and it came with this pedal spanner.

pedal spanner

So I think the easiest thing to do is to write the directions on the spanner!

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    Easier still to call the assistance number.
    – Daniel R Hicks
    Commented Dec 8, 2012 at 18:01
  • I got a similar spanner from Evans Cycles, my advice was going to be to write it on too!
    – DWGKNZ
    Commented Mar 16, 2013 at 20:15
  • Writing it on the tools seems to be the best solution to me. I have tried all of the mnemonics and memory tricks listed here. The problem I always come back to is that one side of the bottom bracket is reverse threaded as well. I can never remember what applies to the bottom bracket and what applies to the pedals.
    – jimchristie ♦
    Commented Mar 17, 2013 at 4:05
  • That reverse side would've been so much clearer if they'd printed it with the spanner facing the opposite way (opening on the right, handle left). As it is, I find it just adds confusion...
    – joharr
    Commented Feb 6, 2020 at 10:33
  • "Hello, Support. Which direction is right an which is left?"
    – Andrew
    Commented Jan 24 at 15:05
7

I don't have the wit to convey the knuckle on chain-teeth pain that happens when taking old pedals out, however, how about 'backwards in, forwards out' ?

The thinking being that when you put new pedals in you have to turn the chainset backwards with your trusty 15mm spanner on the pedal and vice-versa for taking old pedals out.

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7

I just remember it as:

Right Side: Righty tighty lefty loosy

Left Side: Lefty tighty righty loosey

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    That confuses me more than helping! :)
    – geoffc
    Commented May 27, 2011 at 17:08
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    yes it is confusing, but it is fully in line with the way that mechanics think. It is a rule that applies to all threaded interfaces. The only thing you must remember is the exceptions. i.e. gas is backwards.
    – Dave
    Commented May 28, 2011 at 19:15
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Do you know about the "right hand rule". If you curl the fingers of your right hand in the direction you're turning a screw, the screw moves in the direction of your thumb.

The left hand side of your cranks follows the left hand rule.

And, your wife just asked you why you're curling your fingers and staring at your hand.

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  • +1 again, not a mnemonic, per se, but I like it!
    – Yes I use MUMPS
    Commented Apr 10, 2013 at 23:37
5

Recently I found my own approach:

I approach my bicycle from back, put on an wrench/hex key pointing to back and push it down, if needed, with my foot.

I used to do this with my bike upside down, but ended up with some scratches on my hands from drivetrain.

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Drive side - normal

Non-drive side - opposite.

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    Yes! How about: "Right is right and left is wrong"... in the sense that the right pedal works like any bolt/screw tightening to the right or clockwise, while the left pedal works the wrong way round.
    – Zippy
    Commented May 31, 2011 at 15:11
  • ok...but drive side can go on either side...
    – dotjoe
    Commented Jun 13, 2012 at 21:28
4

I always say to myself "back off" - as both pedals unscrew towards the back which helps me remember which way to turn.

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BACK OFF (mnemonic device) TO GET PEDAL OFF

When I'm standing at each pedal with the wrench in the upwards position (I get the most torque this way) I remember the words "Back Off" meaning I turn the wrench towards the back of the bike to get the pedal off.

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    Gidday and welcome to Bicycles Stack Exchange. Thank you for your input - I've lower-cased your comment to make it more legible.
    – Criggie ♦
    Commented Oct 6, 2015 at 10:02
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To tighten, Rotate any of the pedal same direction of the WHEEL's ROTATION if it were to motion FORWARD.

EASY huh.

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Stay on the drive side of the bike and reach over to remove the non-drive-side pedal. Keep the bike upright. In this case, you turn your pedal wrench towards the back of the bike when removing both pedals and you turn it towards the front when installing them. Lead in with taking off the drive side pedal, and then reach over and do the same motion for the non-drive-side. You won't screw it up.

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In the organisation where I worked, it wasn't a case of the right hand not knowing what the left hand was doing; the right hand often didn't know what the RIGHT hand was doing.

In the case of bicycle pedals, the right foot knows that the right-hand thread is good.

Thanks for the other suggestions, and simply for letting me find out which way they go (I worked in a bicycle shop 50 years ago, shame on me.

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    I think I'm just more confused now. :)
    – amcnabb
    Commented Jul 26, 2013 at 17:38
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A simple way to never be in doubt is just put the crankarm with the pedal you want to remove in the forward position (3 o clock), attach the wrench, and pull up towards yourself. You can even put your foot on the pedal while doing this if it is hard to remove.

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The simplest is to look for the "L" and "R" on the respective pedals. Most pedals have them.

If there's no indicator which pedal is left and right, then do a little guess-and-check. If the pedal doesn't start to thread onto the crank after about 1.5 turns then try the other pedal.

Just remember not to force the threads on. They should start easily, and once started should take little force to fully thread. Putting a little grease on the threads is highly recommended, it will prevent corrosion and keep them from ceasing--and provided you snug the threads into the crank there's no extra chance of them coming out.

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To tighten, turn the way the wheels turn when you're moving forwards.

To loosen, turn the way the wheels turn when you're moving backwards.

This works for both 15mm spanners and the assorted hex down the spindle designs you see these days, with no confusion possible.)

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1

I was changing some pedals over today and I noticed that (from the top/12 o'clock) the spanner needs to go towards the rear wheel to loosen and towards the front wheel to tighten.

It helped me more than "clockwise" because I was inserting the allen key into the back of the pedal so it was all backwards if you were thinking about "clockwise", etc.

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This isn't a mnemonic, but this is the technique I use. For both loosening and tightening, the pedal should be positioned such that pushing the wrench downwards would rotate the wheel forwards, regardless of which side pedal you're working on. This means that you can rotate the wrench without holding the crank or the pedal in place, you just need to hold the bike to keep it from rolling forward.

To loosen the pedals, hold the spanner like this and push the end of the wrench down:Loosening the pedals

And to tighten, hold the wrench like this and push down: Tightening the pedals

You don't even have to think about which side you're doing, just whether you're loosening or tightening.

On the other side, the positioning will be the same, with the pedal pointing to the left as you face the bike, and you push down to rotate the wrench. If you have a freewheel, you can't make a mistake, as the pedals will freely rotate if you position them the wrong way.

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How about "Back off Jack" This works when the bike is upright.

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I remember:

Right is Right, or

Might is Right (being the drive side).

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To loosen: Bike upright. (like normal)
Wrench on from the top (which is normal - why would I try put a wrench on a pedal from the bottom when its upright??), pull back. "Back off Jack" By far the easiest way to remember. (3 steps, 2 are obvious, just remember "Back off Jack")

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  • Someone else also suggested this in one of the other answers, but I don't understand why Back off jack would help you remember it. Or, why you need a mnemonic at all, really...
    – Batman
    Commented Jan 30, 2014 at 9:42
  • It's kinda like "Fall forward, spring back."
    – Daniel R Hicks
    Commented Jan 30, 2014 at 12:51
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The problem with a lot of mnemonics is that it depends on which side of the bike you are looking at. Since Shimano pedals are attached using a hex wrench from the side opposite the pedal, the "righty-tighty" rule does not really work effectively. What I remember is the way the bolt has to turn is "ride on, back off". In other words, if you want to put the pedal on, you turn the bolt the direction you would ride (forward on top), where if you want to take it off, you turn it backward (back off -- top turning to rear of bike).

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I chose the internet to find the answer to the question which way does each pedal loosenand from what ive learned I would answer your question with ' put the wrench on the pedal at 12 o'clock like the arm on a clock and turn it towards the back of the bike for both sides to loosen, I may be wrong but I'm about to try and find out for myself.

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I take one old pedal off the bike, compare it to each pedal in the new pair, and use the one whose threads go the same way. Then I remove the other old pedal and replace it with the remaining new one.

I do Moz's thing if the bike has no old pedals, but it's easy enough to glance at them if I replace one at a time.

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I'm pretty sure that "righty tighty, lefty loosey" is the official answer, but I do like the "right is right, and left is wrong" one. Makes more sense to me. It's amazing how I can remember some pretty complicated sequences of stuff about all kinds of things, but this simple concept escapes me every time.

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stand behind your bike, the pedal always removes when it points towards the direction of your rear wheel. just like how it gets left behind as you move forward. lol just my way of remembering

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