Fixing pedal-crank to spindle ( but removeably)

N Cook said:

One crank worked loose this week , but how to refit without causing the same
to happen again?

Copper grease.

--
Membrane

N Cook said:

Been going around for months now with both retaining bolts removed, in the
hope that use would do what butane blow-lamp would not do.
Break the aluminium/steel bond at the square section junction of crank and
bottom bracket spindle.
One crank worked loose this week , but how to refit without causing the same
to happen again?

Thoroughly clean both the BB spindle and the crank arm. Apply a light
coating of grease to the spindle before re-fitting. Allegedly, bi-metal
bonding is avoided by using copper grease, but I just use ordinary cycle
grease. Service bike regularly, including removing and re-attaching
crank arms at least twice a year (admittedly this is easier when you're
retired ;-) )

--
Brian G
www.wetwo.co.uk

N Cook said:

Been going around for months now with both retaining bolts removed,
in the hope that use would do what butane blow-lamp would not do.
Break the aluminium/steel bond at the square section junction of
crank and bottom bracket spindle.
One crank worked loose this week , but how to refit without causing
the same to happen again?

Are you sure there really was a bond, or were the cranks just on bloody
tight?

There are microscopic movements in normal use that should prevent bonding.
I've never had cranks get stuck, even when they were fitted dry and not
removed for many years.

Anyway, grease on the spindle doesn't do any harm (as long as the cranks are
tightened correctly). See
www.sheldonbrown.com/brandt/installing-cranks.html

~PB

Pete Biggs <[email hidden]> wrote in
message news:[email hidden]...

Quoted message said:

N Cook said:

Been going around for months now with both retaining bolts removed,
in the hope that use would do what butane blow-lamp would not do.
Break the aluminium/steel bond at the square section junction of
crank and bottom bracket spindle.
One crank worked loose this week , but how to refit without causing
the same to happen again?

Are you sure there really was a bond, or were the cranks just on bloody
tight?

There are microscopic movements in normal use that should prevent bonding.
I've never had cranks get stuck, even when they were fitted dry and not
removed for many years.

Anyway, grease on the spindle doesn't do any harm (as long as the cranks

are

Quoted message said:

tightened correctly). See
www.sheldonbrown.com/brandt/installing-cranks.html

~PB

I've greased up (non-copper) and banged on with no more than a shoe and
tightened up the bolt with the minimum setting of 30n-m on a torque wrench.

Anyone ever tried , for removal, heating directed at the ali crank and then
freezer spray at either end of the steel followed by "hub puller" or
whatever favoured/available implement of extraction.

I'd liked to have seen some reference to n-m or ft-lbs on that URL, it is
quite fine pitch thread.

N Cook said:

I've greased up (non-copper) and banged on with no more than a shoe
and tightened up the bolt with the minimum setting of 30n-m on a
torque wrench.

That's not too tight, so you might be right about the bonding (and Jobst
Brandt might be wrong!).

Quoted message said:

Anyone ever tried , for removal, heating directed at the ali crank
and then freezer spray at either end of the steel followed by "hub
puller" or whatever favoured/available implement of extraction.

Did you try bashing the end of a spanner with a club hammer?

Quoted message said:

I'd liked to have seen some reference to n-m or ft-lbs on that URL,
it is quite fine pitch thread.

Park Tools and some manufacturers list recommended torque values on their
websites.

~PB

--
--
Pete Biggs <[email hidden]> wrote in
message news:[email hidden]...

Quoted message said:

N Cook wrote:

Did you try bashing the end of a spanner with a club hammer?

No, I usually tend to use a 6 foot scaffold pole on the socket wrench and
jump on it.

Membrane said:

N Cook said:

One crank worked loose this week , but how to refit without causing the same
to happen again?

Copper grease.

--
Membrane

Im still not convinced by greasing cranks.I've read the posts for and
against but I've yet to have a set of sq tpr cranks (torqued to
manufacturers spec) remain on solidly when greased. When torqued to
spec and without grease (stripped clean with spirits) they never move
on me. Technically the same bolt-torque with a greased taper should
allow tighter/more bedded fit, however this doesnt seem to bear out in
my experience. When assembled dry, from the arguments of jobst and
sheldon IIRC, your arms bed in and shift, requiring re-torquing. This
just has never happened to me, and I've had some 10 sets of square
taper cranks so far. I never have problems removing non-greased cranks
with a proper extractor tool, but then I remove them about every 6
months for cleaning etc.

CoyoteBoy said:

Im still not convinced by greasing cranks.

In rec.bicycles.tech the topic of to grease or not to grease is as
controversial as the "Shimano or Campag, which is best" and "Do wheels
hang from or stand on their spokes?" debates. On which basis you might
as well make your own decision and live with half the people telling you
you got it wrong.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

N Cook said:

--
--
Pete Biggs <[email hidden]> wrote in
message news:[email hidden]...

Quoted message said:

N Cook wrote:

Did you try bashing the end of a spanner with a club hammer?

No, I usually tend to use a 6 foot scaffold pole on the socket wrench and
jump on it.

My shed's too small for that, so it has to be the hammer ;-)

--
Brian G
www.wetwo.co.uk

Quoted message said:

"Do wheels hang from or stand on their spokes?" debates

Is the issue more complicated than just sitting on a bike and twanging the
spokes to see if they're under tension? (or have I missed a joke?)

--
Mark T

Mark T said:

Quoted message said:

"Do wheels hang from or stand on their spokes?" debates

Is the issue more complicated than just sitting on a bike and twanging
the spokes to see if they're under tension? (or have I missed a joke?)

Joke? JOKE? People have died from the apoplexy bought on by that debate!

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

Tony Raven said:

Mark T said:

Quoted message said:

"Do wheels hang from or stand on their spokes?" debates

Quoted message said:

Is the issue more complicated than just sitting on a bike and twanging
the spokes to see if they're under tension? (or have I missed a joke?)

Joke? JOKE? People have died from the apoplexy bought on by that debate!

LOL so true. The answer is a). For sure.If the lower spokes are still
under tension then their force must be pulling the bike down,
therefore the top spokes are what resist that. however lower spoke
tension provides massive stabilising effect that prevents the wheel
distorting and collapsing. Anyone who tells me the wheel stands on its
lower spokes needs their head examining 😄

As for the cranks, yes there is literally a 50:50 split in the people
I've talked to about it, each equally convinced.

CoyoteBoy said:

Im still not convinced by greasing cranks.I've read the posts for and
against but I've yet to have a set of sq tpr cranks (torqued to
manufacturers spec) remain on solidly when greased. When torqued to
spec and without grease (stripped clean with spirits) they never move
on me. Technically the same bolt-torque with a greased taper should
allow tighter/more bedded fit, however this doesnt seem to bear out in
my experience. When assembled dry, from the arguments of jobst and
sheldon IIRC, your arms bed in and shift, requiring re-torquing.

Jobst says cranks bed in whether grease was used or not, and that
re-torquing should NOT be done.

Quoted message said:

This
just has never happened to me, and I've had some 10 sets of square
taper cranks so far. I never have problems removing non-greased cranks
with a proper extractor tool, but then I remove them about every 6
months for cleaning etc.

I don't really know if greasing is better than fitting cranks dry, but I am
convinced that greasing doesn't cause any problems at all if the cranks are
fitted tightly. I have no problems with mine.

~PB

Pete Biggs said:

I don't really know if greasing is better than fitting cranks dry, but I
am convinced that greasing doesn't cause any problems at all if the
cranks are fitted tightly. I have no problems with mine.

I'm not coming down on one side of the other of the fence here but the
argument used against greasing is they allow the crank to slide on more
freely so you can more easily reach the point where you risk deforming
the crank by pushing it too far up the taper (which is also aq claimed
risk of retorquing).

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

In article <[email hidden]>, Pete Biggs
[email hidden] says...

Quoted message said:

I don't really know if greasing is better than fitting cranks dry, but I am
convinced that greasing doesn't cause any problems at all if the cranks are
fitted tightly. I have no problems with mine.

I've seen greased cranks work loose, when degreased they stayed put -
that's enough to convince me. It's possibly different with the various
non-square tapers used these days.

Pete Biggs said:

I don't really know if greasing is better than fitting cranks dry, but I am
convinced that greasing doesn't cause any problems at all if the cranks are
fitted tightly. I have no problems with mine.

The only reason I grease the cranks is that I have had creaking cranks
in the past but when I've applied a little grease the creaks and squeaks
have disappeared. Now I routinely apply grease and so far <touching
nearest bit of wood> I've had no more creaking cranks.

--
Brian G
www.wetwo.co.uk

Pete Biggs said:

Jobst says cranks bed in whether grease was used or not, and that
re-torquing should NOT be done.

Ok, fair enough, does he suggest that a bedding crank wont move, or
does he suggest something to take up the slack (lack of bolt tension)
left by bedding?

CoyoteBoy said:

Pete Biggs said:

Jobst says cranks bed in whether grease was used or not, and that
re-torquing should NOT be done.

Ok, fair enough, does he suggest that a bedding crank wont move, or
does he suggest something to take up the slack (lack of bolt tension)
left by bedding?

He suggests there are microscopic movements, and that you should not and
don't need to do anything about it.

~PB

CoyoteBoy said:

Ok, fair enough, does he suggest that a bedding crank wont move, or
does he suggest something to take up the slack (lack of bolt tension)
left by bedding?

IME, when the crank is fitted extremely tightly* to begin with, there's only
a small amount of bedding in after use, and the bolt doesn't come undone --
even when using grease and no threadlock on the threads. I could re-tighten
the bolt a bit, but I don't.

I've been doing this for a number of years on several bikes -- and get no
problems at all -- whereas I did get the occasional problem when I used less
torque and no grease. (The grease might just be coincidence).

* I fit to or near the manufacturer's recommended upper (dry) torque limit,
but with grease. So I'm exceeding the limit. This seems to help rather
than hinder. My theory is that manufacturers are conservative.

~PB