# Why a washer on the pedals?



## Finch Platte (Nov 14, 2003)

I was having issues with the Shimano XT pedals on the bike I recently got. The right pedal had some weird front-to-back slop I didn't like, so I got new pedals. When I took the old ones off, they each had a washer between the crank & the pedal. Why?

Only thing I can think of is maybe it would make them easier to take off? Btw, they weren't, they were on wayyyy too tight, and I might have had issues if I needed to take them off with the tools I carry in my pack. Note to mechanics: they don't need to be that tight!

Any ideas on the washers?


----------



## DIRTJUNKIE (Oct 18, 2000)

Are they front load washers? If so, no wonder your bike is so heavy.


----------



## knutso (Oct 8, 2008)

On some crank arms the washers are necessary. The force that gets the pedals on so tight, comes from you pedaling. On some crank arms that force needs to be dissipated over a washer or else stress risers will cause the arm to break at the eyelet.


----------



## Finch Platte (Nov 14, 2003)

knutso said:


> On some crank arms the washers are necessary. The force that gets the pedals on so tight, comes from you pedaling. On some crank arms that force needs to be dissipated over a washer or else stress risers will cause the arm to break at the eyelet.


I don't agree with the pedals being tight because of my pedaling. On bikes I've had in the past, I know not to crank then down because they don't NEED to be cranked down, and they are not hideously tight when I take them off.

As far as the force needing to be dissipated, I've never heard of that. These are brand new Race Face cranks, shouldn't they have figured out the forces by now so a washer isn't needed?


----------



## mack_turtle (Jan 6, 2009)

I like using a pedal washer because it's easier to achieve and maintain torque with one, and for pedals that have standard 15mm wrench flats, the flat parts don't gouge the side of the pedal. this is vital on cräbon cranks.


----------



## knutso (Oct 8, 2008)

Finch Platte said:


> I don't agree with the pedals being tight because of my pedaling. On bikes I've had in the past, I know not to crank then down because they don't NEED to be cranked down, and they are not hideously tight when I take them off.
> 
> As far as the force needing to be dissipated, I've never heard of that. These are brand new Race Face cranks, shouldn't they have figured out the forces by now so a washer isn't needed?


If pedaling doesn't affect torque, why would reverse threading the non-drive side be necessary??

Race Face alloy arms definitely need the washer.


----------



## knutso (Oct 8, 2008)

Found the pic I was looking for ...


----------



## aerius (Nov 20, 2010)

Finch Platte said:


> I don't agree with the pedals being tight because of my pedaling. On bikes I've had in the past, I know not to crank then down because they don't NEED to be cranked down, and they are not hideously tight when I take them off.


Actually you do need to crank them down pretty firmly, Shimano for instance specs it at 35-55 Nm for torque which is almost 40 foot-pounds. Take a 12" wrench and crank on the end of it with about 35lbs or so, that's pretty tight. There's a reason for that, if the pedal isn't tightened down enough you get fretting at the interface which wears the threads and can start cracks in the end of the crank arm. The other thing that happens is the pedal spindle slowly wears itself into the crank arm, the fretting wears away the surface of the crank arm, then the pedal self tightens itself down a bit but not enough to stop the fretting, then cycle repeats and the pedal slowly eats into the softer aluminum of the crank.


----------



## Strafer (Jun 7, 2004)

some cranks came with washers, like SLX with bash guard required steel washer.


----------



## CrozCountry (Mar 18, 2011)

In some pedals the inner bearing leans on the washer on the crank side of the axle, and the axle itself on the other side.


----------



## Lone Rager (Dec 13, 2013)

In some crank arms, often carbon, the face of the threaded part is recessed below the surface of the crank. If the flange of the pedal spindle is larger than this, it won't seat cleanly in the recess. Pedals washers are needed in this case.


----------



## J.B. Weld (Aug 13, 2012)

Washers distribute load evenly and prevent damage to soft crankarms.



aerius said:


> Actually you do need to crank them down pretty firmly, Shimano for instance specs it at 35-55 Nm for torque which is almost 40 foot-pounds.


Agree^ under tightening can be risky.


----------



## Finch Platte (Nov 14, 2003)

Wow, some good info here. Thanks, guys.


----------



## *OneSpeed* (Oct 18, 2013)

agreed, get them good and tight. I wrecked a set of cranks when i didn't get one pedal tight enough. 

just hit the threads with some grease when installing, and use the washer.


----------



## Nat (Dec 30, 2003)

I never use the washers. They can be like giant spinning knives that might sever my foot off if I crash.


----------



## GreatLakesWaterman (Oct 29, 2013)

Nat said:


> I never use the washers. They can be like giant spinning knives that might sever my foot off if I crash.


Huh? That makes zero sense. The washer sits flat against the crank. Care to share a pic of your foot touching the washer? Thanks in advance.

Sent from my Nexus 6 using Tapatalk


----------



## Nat (Dec 30, 2003)

GreatLakesWaterman said:


> Huh? That makes zero sense. The washer sits flat against the crank. Care to share a pic of your foot touching the washer? Thanks in advance.
> 
> Sent from my Nexus 6 using Tapatalk


----------



## mack_turtle (Jan 6, 2009)

please explain how this washer:










did that to your leg. I am intrigued!

on the other hand, I am also intrigued at the photo I found of someone using Vaseline on pedal threads. for the record, I approve of pedal washers, but not Vaseline as a thread grease.


----------



## s0ul_chicken (Aug 1, 2013)

mack_turtle said:


> on the other hand, I am also intrigued at the photo I found of someone using Vaseline on pedal threads. for the record, I approve of pedal washers, but not Vaseline as a thread grease.


I have always used anti-seize instead of grease - you won't need as much torque to get them installed, or removed.


----------



## Nat (Dec 30, 2003)

mack_turtle said:


> please explain how this washer:
> 
> did that to your leg. I am intrigued!


Round spinning discs can become giant knives. Very dangerous. Should ban their use.


----------



## GreatLakesWaterman (Oct 29, 2013)

Sent from my Nexus 6 using Tapatalk


----------



## CommuterBoy (Oct 4, 2007)

^^ Is that washer not fitting in the recessed area of the crank? I have had them sit funny when I'm not careful on installation... those washers barely fit in there sometimes. It's usually obvious enough that I'd never not notice, but you do have to hold it in the right position when you thread the pedal down sometimes.



Nat said:


> I never use the washers. They can be like giant spinning knives that might sever my foot off if I crash.


:lol:

I'm pretty sure washers are banned in pro XC events.

I was really good about using the washers, but then I had this set of pedals that I moved back and forth between bikes, and at some point one fell off in transition, then I wanted them to match so I took the other one off, and now I've been washerless on at least one or two sets of pedals for quite a while with no issues. I use them when they're there though. When they're not there, I do check to see how the pedal is going to sit against the crank... I've never had a pair of cranks where the contact situation was affected by not having a washer, but I could see the potential issue with the rare, odd crank/pedal combo. Probably this is only going to be an issue with parts that I can't afford, so I'm not too worried about it :lol:


----------



## mack_turtle (Jan 6, 2009)

Nat said:


> Round spinning discs can become giant knives. Very dangerous. Should ban their use.


not sure if serious. are we on the same page at all? look up some photos of pedal washers. I think you are thinking of something completely different, or you're trying to make a joke that's not funny because it makes no sense.


----------



## Nat (Dec 30, 2003)

CommuterBoy said:


> :lol:
> 
> I'm pretty sure washers are banned in pro XC events.


As well they should be. The pro peleton has done without them for decades so why are they needed now?

From the Association of Professional Cyclists (CPA):
"We have been talking about the risks of the use of the crank washers since months and we have sent letters in the past to the UCI and the organizers to avoid such risks. Now they are going to finally listen to our voice. We don't want to stop the progress but we want to find common solutions for the introduction of new technologies without risks for the riders and definitely with their involvment."


----------



## mack_turtle (Jan 6, 2009)

WTF are you talking about? how is putting a tiny washer between your pedal and your crank arm a "new technology" and how could it cut your leg?


----------



## CommuterBoy (Oct 4, 2007)

mack_turtle said:


> WTF are you talking about?


Nothin' just bike stuff.


----------



## mack_turtle (Jan 6, 2009)

you guys have a weird sense of humor. I'm out.


----------



## smilinsteve (Jul 21, 2009)

mack_turtle said:


> please explain how this washer:
> 
> 
> 
> ...


I am intrigued as well. 


> on the other hand, I am also intrigued at the photo I found of someone using Vaseline on pedal threads. for the record, I approve of pedal washers, but not Vaseline as a thread grease.


I've used vaseline, and I've even used chap stick or Carmex. Anything is better than installing them dry. It's usually short term for me, as I swap pedals fairly frequently.


----------



## CommuterBoy (Oct 4, 2007)

Don't be mad it's just that it's the first time I've known about something that someone else didn't already know about :lol:

UCI suspends road disc brakes in races after Ventoso injury | Cyclingnews.com


----------



## smilinsteve (Jul 21, 2009)

aerius said:


> Actually you do need to crank them down pretty firmly, Shimano for instance specs it at 35-55 Nm for torque which is almost 40 foot-pounds. Take a 12" wrench and crank on the end of it with about 35lbs or so, that's pretty tight. There's a reason for that, if the pedal isn't tightened down enough you get fretting at the interface which wears the threads and can start cracks in the end of the crank arm. The other thing that happens is the pedal spindle slowly wears itself into the crank arm, the fretting wears away the surface of the crank arm, then the pedal self tightens itself down a bit but not enough to stop the fretting, then cycle repeats and the pedal slowly eats into the softer aluminum of the crank.


Interesting. I learned something. 
I've always tightened pedals barely over hand tight, to be able to remove them with an allen wrench and not need a long pedal wrench. I've never had a problem. When I remove pedals they are always tighter than when they were installed, so I just figured that pedaling takes care of all the tightening I need. 
Even though I now see the technical reason for a potential problem, since its never been an issue for me, I probably won't change what I do. Tight pedals are a pain!


----------



## mack_turtle (Jan 6, 2009)

disc brake rotors and pedal washers are not the same thing.

and disc brakes on road bikes do not affect people who are not racing and not riding among a "peleton."


----------



## smilinsteve (Jul 21, 2009)

They better remove the chainrings as well, just to be safe.


----------



## CommuterBoy (Oct 4, 2007)

I'm no physicist, but it makes a little sense to me that if they're significantly tighter when you remove them than when you put them on, you maybe didn't tighten them down enough and they tightened themselves due to that whole fretting thing... if you tighten them properly, they're about the same tightness when you remove them, because they had a good solid relationship going with the threads... just the basic spinning of the pedal should never be enough to actually tighten the crank/pedal threads, unless the bearings are jacked. If they're tightening themselves, you have movement where you shouldn't have it.


----------



## CommuterBoy (Oct 4, 2007)

mack_turtle said:


> disc brake rotors and pedal washers are not the same thing.


Maybe that's why my brakes suck. Hang on I gotta check something...


----------



## Harold (Dec 23, 2003)

mack_turtle said:


> disc brake rotors and pedal washers are not the same thing.
> 
> and disc brakes on road bikes do not affect people who are not racing and not riding among a "peleton."


Come on - I thought the joke was funny. You're just sore 'cause you got trolled.


----------



## mack_turtle (Jan 6, 2009)

no, I am genuinely curious about what he was referring to as "spinning knives." I assume he was pretending to be confused about something else, but because that other thing is not readily apparent, it's not funny yet. what's the "joke?"


----------



## Derek200 (Jun 16, 2015)

He made a joke referencing the very recent band of disc brakes. Some pro racers made comments that they were dangerous. It's ludicrous to think about and so I thought it was funny hat he applied this recent news event to the pedal washers. 


Sent from my iPhone using Tapatalk


----------



## CommuterBoy (Oct 4, 2007)

The original statement from Ventoso talked about how crazy the UCI was to allow these "spinning knives" in the pro peloton (referring to disc brake rotors). I saw "spinning knives" in that comment on here and instantly knew dude was joking about the recent disc brake scandal. That was it. That was the whole joke. Dang it's not that funny now. You sort of killed it? haha. Had to be there? It was funny to me?


----------



## mack_turtle (Jan 6, 2009)

good work- proud of myself for ruining someone else's joke.

*pats self on back*

(sorry, I skipped that disc brake on road racers thread)


----------



## Nat (Dec 30, 2003)

Harold said:


> Come on - I thought the joke was funny. You're just sore 'cause you got trolled.


It started out simply as a commentary on current events but when they didn't get it things just got out of control. I was on the verge of banning myself.


----------



## borabora (Feb 16, 2011)

How to make a thread on washers interesting:

Just add spinning knives and Vaseline!


----------



## Nat (Dec 30, 2003)

mack_turtle said:


> good work- proud of myself for ruining someone else's joke.
> 
> *pats self on back*


I bet you're fun to hang out with.


----------



## net wurker (Sep 13, 2007)

I believe that the reason the washers are there is that it's a big conspiracy by the washer industry.


----------



## Harold (Dec 23, 2003)

CommuterBoy said:


> The original statement from Ventoso talked about how crazy the UCI was to allow these "spinning knives" in the pro peloton (referring to disc brake rotors). I saw "spinning knives" in that comment on here and instantly knew dude was joking about the recent disc brake scandal. That was it. That was the whole joke. Dang it's not that funny now. You sort of killed it? haha. Had to be there? It was funny to me?


I'll laugh at any joke at Ventoso's expense at this point. He came off as being quite a crybaby with his spinning knives comment. 'cause, you know, roadies never got injured in pileups until disc brakes.


----------



## CommuterBoy (Oct 4, 2007)

I can't believe we've actually allowed pro races to happen with everyone in the field carrying around something actually called a "skewer" for so long :lol:


----------



## GreatLakesWaterman (Oct 29, 2013)

Unfollowing...

Sent from my Nexus 6 using Tapatalk


----------



## Harold (Dec 23, 2003)

GreatLakesWaterman said:


> Unfollowing...
> 
> Sent from my Nexus 6 using Tapatalk


that cuts.....

like giant, spinning knives


----------



## DIRTJUNKIE (Oct 18, 2000)

Derek200 said:


> He made a joke referencing the very recent band of disc brakes. Some pro racers made comments that they were dangerous. It's ludicrous to think about and so I thought it was funny hat he applied this recent news event to the pedal washers.
> 
> Sent from my iPhone using Tapatalk





CommuterBoy said:


> The original statement from Ventoso talked about how crazy the UCI was to allow these "spinning knives" in the pro peloton (referring to disc brake rotors). I saw "spinning knives" in that comment on here and instantly knew dude was joking about the recent disc brake scandal. That was it. That was the whole joke. Dang it's not that funny now. You sort of killed it? haha. Had to be there? It was funny to me?





Nat said:


> It started out simply as a commentary on current events but when they didn't get it things just got out of control. I was on the verge of banning myself.


I got the joke right off the bat. That's not saying much though I'm a bit off center anyway. I even tried to rep Nat but was denied. That was before this whole conversation fell off a cliff.

Back to washer talk I'm on the edge of my seat here.


----------



## OLx6 (Feb 5, 2011)

Maybe the industry can develop a composite washer which would be lighter of course but not as sharp as a standard steel washer. I am thinking a washer made from graphene mixed with latex. Who would ban these?


----------



## Finch Platte (Nov 14, 2003)

smilinsteve said:


> I am intrigued as well.
> 
> I've used vaseline, and I've even used chap stick or Carmex. Anything is better than installing them dry. It's usually short term for me, as I swap pedals fairly frequently.


Are you sure you're talking about swapping pedals?


----------



## tednugent (Apr 16, 2009)

Pedal washers can be used to slightly adjust your fit.


Sent from my iPhone. There may be horrible grammar and misspelling involved


----------



## jbdnavy2 (Apr 19, 2016)

they are there to protect the crankset. some pedal will dig in causing score marks. for carbon they are mostly needed. since most cranks are softer than the steel spindles the washer protects and evens the load


----------



## Curveball (Aug 10, 2015)

mack_turtle said:


> not sure if serious. are we on the same page at all? look up some photos of pedal washers. I think you are thinking of something completely different, or you're trying to make a joke that's not funny because it makes no sense.


I got a good laugh.

I also saw it as a funny joke from the start. I guess you have to read the road disc brakes thread to really get it.


----------



## bamwa (Mar 15, 2010)

Mack turtle and great lakes waterman deserve bonehead of the month awards. Man.

p.s. Thanks Nat for keeping it real. although I don't see how you cut your leg like that with your keyboard and mouse. Must be a mouse bite.


----------



## Chicane32 (Jul 12, 2015)

I use 2 washers on each peddle to keep my pedal extended out past my crank boot. My pedal won't spin freely with 1 washer installed.


----------



## Harryman (Jun 14, 2011)

I've built up and ridden bikes with AL crank arms for over 25 years without an issue before I even saw a pedal washer. The first time I got that little ziplock bag, I was like "Wtf?"

It's just a way for the man to seduce us with pedals that have the smallest pedal/crank interface possible to keep the weight down and plastic crank arms with the smallest aluminum insert possible to keep the weight down. Once we're glowing with self satisfaction at our combined weight savings, they force us to add a hefty steel washer into our elegant system to keep from destroying our entire drivetrain.

Now I'm full of anxiety, run 'em commando like I always have? Drill out the washers to minimize the damage, or man up and accept the 4 extra grams?

BTW, I'll never look at skewers the same way again...... :thumbsup:


----------



## Gritter (Dec 21, 2010)

knutso said:


> If pedaling doesn't affect torque, why would reverse threading the non-drive side be necessary??
> 
> Race Face alloy arms definitely need the washer.


Nothing to do with the washers, but I just thought Sheldon Brown's take on it was interesting:

_"The left pedal has a left (reverse) thread. The reason for this is not obvious: The force from bearing friction would, in fact, tend to unscrew pedals threaded in this manner. It is not the bearing friction that makes pedals unscrew themselves, but a phenomenon called "precession".

You can demonstrate this to yourself by performing a simple experiment. Hold a pencil loosely in one fist, and move the end of it in a circle. You will see that the pencil, as it contacts the inside of your fist, rotates in the opposite direction. This occurs because the pencil's diameter is smaller than that of the opening in your fist. The external threads of the pedal axle are slightly smaller, also, than the internal threads of the crank -- or they wouldn't fit!

Ignorant people outside the bicycle industry sometimes make the astonishing discovery that the way it has been done for 100 years is "wrong." "Look at these fools, they go to the trouble of using a left thread on one pedal, then the bozos go and put the left thread on the wrong side! Shows that bicycle designers have no idea what they are doing..."

Another popular theory of armchair engineers is that the threads are done this way so that, if the pedal bearing locks up, the pedal will unscrew itself instead of breaking the rider's ankle.

The left-threaded left pedal was not the result of armchair theorizing, it was a solution to a real problem: people's left pedals kept unscrewing! We have read that this was invented by the Wright brothers, but we are not sure of this."_


----------

