Pedal Torque Spec.



P

Paul Kopit

Guest
Why do pedals have to be so tight in crankarms?

I finally got my first torque wrench, $9.99 at Harbor Freight, and I
am playing with the new toy. The specification for a pedal into a
crankarm is ~25 ft lbs. That seems high to me. I've been using a 5"
hex key and getting the pedal in just beyond hand tight. I can remove
the pedal with the same key and holding the arm with my hand and
working the wrench with my fingers.
 
In article <[email protected]>,
Paul Kopit <[email protected]> wrote:

> Why do pedals have to be so tight in crankarms?
>
> I finally got my first torque wrench, $9.99 at Harbor Freight, and I
> am playing with the new toy. The specification for a pedal into a
> crankarm is ~25 ft lbs. That seems high to me. I've been using a 5"
> hex key and getting the pedal in just beyond hand tight. I can remove
> the pedal with the same key and holding the arm with my hand and
> working the wrench with my fingers.


25 ft-lb isn't really that high, and sounds about right to me, for that
application. Those hex key fittings make it pretty hard to obtain
enough torque for a pedal.

My suspicion is that the hex fitting is intended to speed installation,
but you still need to use the flats to get the joint tight enough.

--
Ted Bennett
Portland, OR
 
On Wed, 02 Mar 2005 17:24:48 GMT, Paul Kopit
<[email protected]> may have said:

>Why do pedals have to be so tight in crankarms?


Because they come loose, wallowing out the hole in the crank, if they
aren't. This type of behavior is viewed with disfavor by most.

>I finally got my first torque wrench, $9.99 at Harbor Freight, and I
>am playing with the new toy. The specification for a pedal into a
>crankarm is ~25 ft lbs. That seems high to me.


Huh? That seems low. I'd expect a higher figure. Are you sure you
weren't looking at the figure for the crank retaining bolts?

> I've been using a 5"
>hex key and getting the pedal in just beyond hand tight. I can remove
>the pedal with the same key and holding the arm with my hand and
>working the wrench with my fingers.


Oh. Clipless. Be advised that it's much more common for pedals to
come loose when tightened via that hex recess than via the flats...but
of course, many clipless pedals have no flats, and the ability of the
hex recess to withstand torque is not as high as the flats.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
 
On Wed, 02 Mar 2005 12:48:19 -0600, Werehatrack
<[email protected]> wrote:

>On Wed, 02 Mar 2005 17:24:48 GMT, Paul Kopit
><[email protected]> may have said:
>
>>Why do pedals have to be so tight in crankarms?

>
>Because they come loose, wallowing out the hole in the crank, if they
>aren't. This type of behavior is viewed with disfavor by most.
>
>>I finally got my first torque wrench, $9.99 at Harbor Freight, and I
>>am playing with the new toy. The specification for a pedal into a
>>crankarm is ~25 ft lbs. That seems high to me.

>
>Huh? That seems low. I'd expect a higher figure. Are you sure you
>weren't looking at the figure for the crank retaining bolts?


[snip]

Dear Werehatrack,

Park Tool recommends about 25 foot-pounds for Shimano pedal
into crank:

http://www.parktool.com/repair_help/torque.shtml

The range for various brands is shown as 276 to 354 inch
pounds, or about 23 to 30 foot pounds.

The exchange above may be an example of how people tend to
over (or under) tighten fasteners according to private
notions.

Carl Fogel
 
Paul Kopit writes:

> Why do pedals have to be so tight in cranks?


> I finally got my first torque wrench, $9.99 at Harbor Freight, and I
> am playing with the new toy. The specification for a pedal into a
> crank is ~25 ft lbs. That seems high to me. I've been using a 5"
> hex key and getting the pedal in just beyond hand tight. I can
> remove the pedal with the same key and holding the arm with my hand
> and working the wrench with my fingers.


You probably can't get pedals up to 25ft lbs with a hex key, that
feature bing for quick assembly while the wrench flats for final
tightening. Just the same, all that tightness will not prevent your
pedals from working in the threads, the being no contact in that
interface to take up the load in compression.

The face of the pedal spindle is small, flat and at right angles to
pedaling forces while the threads are at 60 degrees, ideal of small
angular displacements of the spindle. beyond that, a left hand thread
is required to keep left pedals from falling out, regardless of how
tight you make them. Inspecting the contact face of a pedal crank
after significant use will reveal an eroded wear pattern, where the
spindle face bore, from which cracks radiate that can ultimately cause
the pedal eye to break out.

I have modified the contact shoulder on the pedal spindle to a 90
degree cone and have ended my stream of crank failures at that
interface. This solution was adopted by the auto industry for wheel
lug nuts nearly 100 years ago to keep left side wheels from unscrewing
and separating from cars. As with cars it would make left hand thread
unnecessary and put an end to crank failures at that junction.
Unfortunately bicycles, that have been around longer than cars, were
orphaned by engineering for their more powerful derivatives.

Jobst Brandt
[email protected]
 
Just the same, all that tightness will not prevent your
pedals from working in the threads, there being no contact in that
interface to take up the load in compression
 
Paul Kopit wrote:
> Why do pedals have to be so tight in crankarms?
>
> I finally got my first torque wrench, $9.99 at Harbor Freight, and I
> am playing with the new toy. The specification for a pedal into a
> crankarm is ~25 ft lbs. That seems high to me. I've been using a 5"
> hex key and getting the pedal in just beyond hand tight. I can remove
> the pedal with the same key and holding the arm with my hand and
> working the wrench with my fingers.


And for you that seems to be tight enough. So be it. No
reason for you to change.

With a wider range of materials , quality and rider habits,
we find that's not enough torque. Yes, pedals should
tighten in use. But you have to get past the first curb
jump outside our door to display the effect.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
the factory, inexpensive or mid range asian 10 speeds, i've taken apart
had the pedal/cranks glued in solid preventing liability for torn
scrotum
search to "diy pedal removal"
red loctite spread ona clean wire brushed surface prevents tioghtening
and loodesening
 
Paul Kopit <[email protected]> wrote:

>I finally got my first torque wrench, $9.99 at Harbor Freight, and I
>am playing with the new toy. The specification for a pedal into a
>crankarm is ~25 ft lbs. That seems high to me. I've been using a 5"
>hex key and getting the pedal in just beyond hand tight. I can remove
>the pedal with the same key and holding the arm with my hand and
>working the wrench with my fingers.


Lots of people are shocked at how tight stuff is SUPPOSED to be when
they finally get a torque wrench (realizing they've been
under-tightening most things for years).

OTOH, sometimes they are shocked at how LITTLE torque is recommended
on some fasteners (like those on an aluminum stem faceplate).

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame
 
> I have modified the contact shoulder on the pedal spindle to a 90
> degree cone and have ended my stream of crank failures at that
> interface. This solution was adopted by the auto industry for wheel
> lug nuts nearly 100 years ago to keep left side wheels from unscrewing
> and separating from cars. As with cars it would make left hand thread
> unnecessary and put an end to crank failures at that junction.
> Unfortunately bicycles, that have been around longer than cars, were
> orphaned by engineering for their more powerful derivatives.
>
> Jobst Brandt


Jobst: If such a system (cone-shaped contact area between pedal & crank) is
both superior *and* necessary (the latter part being significant, as "good
enough" has, in fact, gotten us pretty far), it's surprising that Shimano
hasn't come up with a new system since, after all, it would bind purchases
ever more tightly to them.

They couldn't simply offer it up without some tangible benefit (besides the
fact that you and a small number of others have broken cranks). If it's
truly a superior system, I would think it would allow a redesign of the
interface such that a lighter-weight crank/pedal combination might result.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com
 
On Thu, 03 Mar 2005 06:08:26 GMT,
[email protected] wrote:

[snip]

>The reason Shimano hasn't done anything along these lines is that they
>don't know about it. They have no way of knowing that the pedal
>attachment is flawed since they do not discuss any technical matters
>with anyone who doesn't have a patent disclosure and they do not read
>these newsgroups. I got a basically rude letter from Shimano making
>this clear. The end of the letter underscored that by saying that
>Shimano has never used an outside idea in anything they have brought
>to market. In other words, don't bother us further. Although I don't
>believe that claim, the sentiment expressed made clear how self
>impressed the company is.
>
>Jobst Brandt
>[email protected]


Dear Jobst,

Let me get this straight . . .

You're saying that you--Jobst Brandt, of all people!--got a
rude, self-impressed reply that rejected your idea?

Carl Fogel
 
In article <[email protected]>,
[email protected] says...
> > The reason Shimano hasn't done anything along these lines is that they
> > don't know about it. They have no way of knowing that the pedal
> > attachment is flawed since they do not discuss any technical matters
> > with anyone who doesn't have a patent disclosure and they do not read
> > these newsgroups. I got a basically rude letter from Shimano making
> > this clear. The end of the letter underscored that by saying that
> > Shimano has never used an outside idea in anything they have brought
> > to market. In other words, don't bother us further. Although I don't
> > believe that claim, the sentiment expressed made clear how self
> > impressed the company is.

>
> My take on their sentiment is different than yours. While it may appear
> arrogant, it's more likely a legal stance to protect patents and products.
> They're a changed company since essentially losing the spd system to the
> public domain. They don't want to pay royalties (wonder why there's no
> threadless Shimano headset?) nor do they wish to give anything away.
>

Hey Jobst, HP was like that (I worked there a long time ago) and that
attitude was legally driven too. Coming from HP Labs I thought that
process would have driven you nuts on a daily basis and would have been
almost inescapable - but maybe being a labs insider you had your ways. (I
realise you can't easily comment :)

Besides, if Shimano was actually doing something about that aspect of
pedal design, the shut-out response you got would be especially necessary
from their perspective.
 
On Thu, 03 Mar 2005 01:09:25 -0700, [email protected] wrote:

>On Thu, 03 Mar 2005 06:08:26 GMT,
>[email protected] wrote:
>
>[snip]
>
>>The reason Shimano hasn't done anything along these lines is that they
>>don't know about it. They have no way of knowing that the pedal
>>attachment is flawed since they do not discuss any technical matters
>>with anyone who doesn't have a patent disclosure and they do not read
>>these newsgroups. I got a basically rude letter from Shimano making
>>this clear. The end of the letter underscored that by saying that
>>Shimano has never used an outside idea in anything they have brought
>>to market. In other words, don't bother us further. Although I don't
>>believe that claim, the sentiment expressed made clear how self
>>impressed the company is.
>>
>>Jobst Brandt
>>[email protected]

>
>Dear Jobst,
>
>Let me get this straight . . .
>
>You're saying that you--Jobst Brandt, of all people!--got a
>rude, self-impressed reply that rejected your idea?


The grand circle of life is complete.

Ron
 
right! one excercise to get your hands and brain up to speed with amuzi
and sheldon brown:
drill holes ij a board or used bed frame angle iron or...steel is best
and set machine bolts in then prctice screwing various sizes down with
or without grease and loctite
then do it by hand and test to see what torque level the bolt's at
and torque to hand.
also find that one reading-hands or hand and t-wrench-upright and the
bench is different than laying on your back under the trans or at the
BB kneeling on the groung or bent over or-
the t-wrench takes most of the variability outof the muscular-newrvous
system's positionings
 
Bruce Graham writes:

>>> The reason Shimano hasn't done anything along these lines is that
>>> they don't know about it. They have no way of knowing that the
>>> pedal attachment is flawed since they do not discuss any technical
>>> matters with anyone who doesn't have a patent disclosure and they
>>> do not read these newsgroups. I got a basically rude letter from
>>> Shimano making this clear. The end of the letter underscored that
>>> by saying that Shimano has never used an outside idea in anything
>>> they have brought to market. In other words, don't bother us
>>> further. Although I don't believe that claim, the sentiment
>>> expressed made clear how self impressed the company is.


>> My take on their sentiment is different than yours. While it may
>> appear arrogant, it's more likely a legal stance to protect patents
>> and products. They're a changed company since essentially losing
>> the SPD system to the public domain. They don't want to pay
>> royalties (wonder why there's no threadless Shimano headset?) nor
>> do they wish to give anything away.


> Hey Jobst, HP was like that (I worked there a long time ago) and
> that attitude was legally driven too. Coming from HP Labs I thought
> that process would have driven you nuts on a daily basis and would
> have been almost inescapable - but maybe being a labs insider you
> had your ways. (I realise you can't easily comment :)


That's not been my experience. I have seen plenty of outside ideas
presented and license agreements made for products. Unfortunately
Carly sold off a bunch of these things and got rid of Agilent, the
basic strength of HP. This trend started earlier with emphasis on
consumer computing products instead of high tech instruments.

> Besides, if Shimano was actually doing something about that aspect
> of pedal design, the shut-out response you got would be especially
> necessary from their perspective.


Not at all. This concept is fully in the public domain and they could
prove that easily... if they were aware of it. I have talked to
Shimano employees who told me at the end of our conversation that they
were unable to do anything. Even mentioning the idea could get them
fired so everything we talked about and the hardware they saw was
essentially bulk erased.

Jobst Brandt
[email protected]
 
[email protected] wrote:


>
> Not at all. This concept is fully in the public domain and they could
> prove that easily... if they were aware of it. I have talked to
> Shimano employees who told me at the end of our conversation that they
> were unable to do anything. Even mentioning the idea could get them
> fired so everything we talked about and the hardware they saw was
> essentially bulk erased.
>
> Jobst Brandt
> [email protected]


I do think Shimano would like to have some proprietary crank/pedal
interface that would "bind purchases to them", but the motivation would
have to be other than fixing something that they won't confess is
flawed. We'll see.

In the meantime, smaller manufacturers of cranks and pedals would seem
to be a more receptive sector to present the "lug nut" design. Ritchey
might be a good choice, or maybe a collaboration with Crank Brothers and
FSA. I've broken three cranks across the pedal eye - I'll put my name
on the pre-order list.
 
Diablo Scott wrote:

> [email protected] wrote:


>> Not at all. This concept is fully in the public domain and they
>> could prove that easily... if they were aware of it. I have talked
>> to Shimano employees who told me at the end of our conversation that
>> they were unable to do anything. Even mentioning the idea could get
>> them fired so everything we talked about and the hardware they saw
>> was essentially bulk erased.


> I do think Shimano would like to have some proprietary crank/pedal
> interface that would "bind purchases to them", but the motivation
> would have to be other than fixing something that they won't confess
> is flawed. We'll see.


For that it would have to be proprietary, and Jobst's design is already in the
public domain.

> In the meantime, smaller manufacturers of cranks and pedals would seem
> to be a more receptive sector to present the "lug nut" design.
> Ritchey might be a good choice, or maybe a collaboration with Crank
> Brothers and FSA. I've broken three cranks across the pedal eye -
> I'll put my name on the pre-order list.


Two here. However, most people replace cranks or bikes long before that
happens. Even with me that's the case, and I'm not exactly a regular
bike-shopper.

Unfortunately this won't be fixed until someone winds up under a bus, and gets
Jobst as an expert witness in the resulting lawsuit.

Matt O.
 
In article <[email protected]>,
[email protected] says...
> Bruce Graham writes:
>
> >>> The reason Shimano hasn't done anything along these lines is that
> >>> they don't know about it. They have no way of knowing that the
> >>> pedal attachment is flawed since they do not discuss any technical
> >>> matters with anyone who doesn't have a patent disclosure and they
> >>> do not read these newsgroups. I got a basically rude letter from
> >>> Shimano making this clear. The end of the letter underscored that
> >>> by saying that Shimano has never used an outside idea in anything
> >>> they have brought to market. In other words, don't bother us
> >>> further. Although I don't believe that claim, the sentiment
> >>> expressed made clear how self impressed the company is.

>
> >> My take on their sentiment is different than yours. While it may
> >> appear arrogant, it's more likely a legal stance to protect patents
> >> and products. They're a changed company since essentially losing
> >> the SPD system to the public domain. They don't want to pay
> >> royalties (wonder why there's no threadless Shimano headset?) nor
> >> do they wish to give anything away.

>
> > Hey Jobst, HP was like that (I worked there a long time ago) and
> > that attitude was legally driven too. Coming from HP Labs I thought
> > that process would have driven you nuts on a daily basis and would
> > have been almost inescapable - but maybe being a labs insider you
> > had your ways. (I realise you can't easily comment :)

>
> That's not been my experience. I have seen plenty of outside ideas
> presented and license agreements made for products. Unfortunately
> Carly sold off a bunch of these things and got rid of Agilent, the
> basic strength of HP. This trend started earlier with emphasis on
> consumer computing products instead of high tech instruments.
>

As I recall, the field organisations where I worked were quite sensibly
more locked down than the Labs process you describe.

I agree with your thoughts on Carly.
I assume you have seen http://www.everythingispossible.com

> > Besides, if Shimano was actually doing something about that aspect
> > of pedal design, the shut-out response you got would be especially
> > necessary from their perspective.

>
> Not at all. This concept is fully in the public domain and they could
> prove that easily... if they were aware of it. I have talked to
> Shimano employees who told me at the end of our conversation that they
> were unable to do anything. Even mentioning the idea could get them
> fired so everything we talked about and the hardware they saw was
> essentially bulk erased.
>

mind boggling stuff.
 
On Thu, 03 Mar 2005 18:23:49 GMT, [email protected] may
have said:

>[snip] I have talked to
>Shimano employees who told me at the end of our conversation that they
>were unable to do anything. Even mentioning the idea could get them
>fired so everything we talked about and the hardware they saw was
>essentially bulk erased.


It would be a rather intense form of karmic justice if they, in their
enforced ignorance, proceeded to come up with precisely the same
solution that you've devised, filed for a patent and had it
issued...and then saw that patent destroyed by disclosure of the
public domain release you've already given for the idea.

Sadly, I doubt that this will come to pass, but if it does, I will
relish the moment.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.