Square-taper cranks won't come off. Tricks?

On Tuesday, May 23, 2017 at 12:23:51 AM UTC-7, John B. wrote:
On Mon, 22 May 2017 13:43:19 -0700, Joerg
wrote:

The BB on my steel-frame bike is knackered and I can't get the cranks
off the square tapers anymore. Afraid I'll strip out the thread of the
puller tool. Various penetrating sprays didn't help.

From the last time the BB was replaced the bike experienced a transport
across the Atlantic on a ship which probably hasn't helped matters.

Any tricks of the trade?

(1) screw the crank puller into the crank all the way, tighten
everything and give the puller a sharp rap with a hammer. I don't mean
a two handed welt intended to drive it through the bottom bracket and
out the other side, just a sharp rap.

Some times a bit of a shock is all it takes.

(2) get everything set and then heat the crank with a hair drier. If
you can get the aluminum crank hot enough so that you can't hold your
finger on it that would be about right. Then a sharp rap and see.

(3) Take the bike to your local bike shop, describe your attempts at
removing the cranks and then say, "Can I pick it up in a week, from
next Monday?".

That's the normal way John, but I assume that Jeorg already has tried that. Lightly heating usually works through simple expansion.

On 2017-05-22 13:43, Joerg wrote:
The BB on my steel-frame bike is knackered and I can't get the cranks
off the square tapers anymore. Afraid I'll strip out the thread of the
puller tool. Various penetrating sprays didn't help.

From the last time the BB was replaced the bike experienced a transport
across the Atlantic on a ship which probably hasn't helped matters.

Any tricks of the trade?


Folks, thanks for all your input. I finally got it off after taking a
wooden mallet to the wrench that was turning the puller yesterday night.
I figured if I strip the puller I'd just grind everything off and go to
Octalink or whatever. AFAIK Octalink won't need a puller.

BTW, that puller where the thread got stripped was not a Harborfreight
deal but an expensive commercial grade version from a professional mechanic.

And yes, I plan to re-use the cranks if possible. I tightened up the old
Shimano 600 BB. The large chain ring had almost 1/10" play and now none.
Let's see if it has some life in it. If not it'll get replaced. Shimano
offers one kind (UN26 or so) with one nut being plastic and another with
steel but more than 2x the price. Does anyone know whether the plastic
ones hold up for people who mash up hills with some load on the bike? I
mean 8-10k miles, since I don't expect much more out of a BB anyhow.

--
Regards, Joerg

http://www.analogconsultants.com/

On Tuesday, May 23, 2017 at 7:18:56 AM UTC-7, Joerg wrote:
On 2017-05-22 13:43, Joerg wrote:
The BB on my steel-frame bike is knackered and I can't get the cranks
off the square tapers anymore. Afraid I'll strip out the thread of the
puller tool. Various penetrating sprays didn't help.

From the last time the BB was replaced the bike experienced a transport
across the Atlantic on a ship which probably hasn't helped matters.

Any tricks of the trade?


Folks, thanks for all your input. I finally got it off after taking a
wooden mallet to the wrench that was turning the puller yesterday night.
I figured if I strip the puller I'd just grind everything off and go to
Octalink or whatever. AFAIK Octalink won't need a puller.

BTW, that puller where the thread got stripped was not a Harborfreight
deal but an expensive commercial grade version from a professional mechanic.

And yes, I plan to re-use the cranks if possible. I tightened up the old
Shimano 600 BB. The large chain ring had almost 1/10" play and now none.
Let's see if it has some life in it. If not it'll get replaced. Shimano
offers one kind (UN26 or so) with one nut being plastic and another with
steel but more than 2x the price. Does anyone know whether the plastic
ones hold up for people who mash up hills with some load on the bike? I
mean 8-10k miles, since I don't expect much more out of a BB anyhow.

Octalink does not work with square taper. The plastic retaining ring will hold up fine on a UN-whatever, although the original Shimano 600 used an asymmetrical BB, IIRC.

-- Jay Beattie.

"Joerg" wrote in message
...
The BB on my steel-frame bike is knackered and I can't get the cranks off
the square tapers anymore. Afraid I'll strip out the thread of the puller
tool. Various penetrating sprays didn't help.

The first puller tool I bought was NFG - it was pretty rare that it didn't
strip the thread. The one I bought from Halfords has worked OK on even the
difficult cranks.

Most of the alternatives involve varying degrees of damage.

Hammering it is likely to destroy the BB ball bearings and cups. Heat can
work, but the cranks are usually coated and will be ruined.

If it requires extreme violence - you could damage the frame. I'd hacksaw
the ends off the spindle so I can dismantle the BB bearing and start over
with new parts.

Some copper no-seize grease on square taper reassembly might make things
easier next time.

On Tuesday, May 23, 2017 at 10:58:39 AM UTC-7, Ian Field wrote:
"Joerg" wrote in message
...
The BB on my steel-frame bike is knackered and I can't get the cranks off
the square tapers anymore. Afraid I'll strip out the thread of the puller
tool. Various penetrating sprays didn't help.

The first puller tool I bought was NFG - it was pretty rare that it didn't
strip the thread. The one I bought from Halfords has worked OK on even the
difficult cranks.

Most of the alternatives involve varying degrees of damage.

Hammering it is likely to destroy the BB ball bearings and cups. Heat can
work, but the cranks are usually coated and will be ruined.

If it requires extreme violence - you could damage the frame. I'd hacksaw
the ends off the spindle so I can dismantle the BB bearing and start over
with new parts.

Some copper no-seize grease on square taper reassembly might make things
easier next time.

My Park crank tool has always worked IF and only if you screw it in all the way. And tighten it against the stops.

On Tuesday, May 23, 2017 at 10:58:39 AM UTC-7, Ian Field wrote:
"Joerg" wrote in message
...
The BB on my steel-frame bike is knackered and I can't get the cranks off
the square tapers anymore. Afraid I'll strip out the thread of the puller
tool. Various penetrating sprays didn't help.

The first puller tool I bought was NFG - it was pretty rare that it didn't
strip the thread. The one I bought from Halfords has worked OK on even the
difficult cranks.

Most of the alternatives involve varying degrees of damage.

Hammering it is likely to destroy the BB ball bearings and cups. Heat can
work, but the cranks are usually coated and will be ruined.

If it requires extreme violence - you could damage the frame. I'd hacksaw
the ends off the spindle so I can dismantle the BB bearing and start over
with new parts.

Some copper no-seize grease on square taper reassembly might make things
easier next time.

Why Copper

On 2017-05-23 08:29, jbeattie wrote:
On Tuesday, May 23, 2017 at 7:18:56 AM UTC-7, Joerg wrote:
On 2017-05-22 13:43, Joerg wrote:
The BB on my steel-frame bike is knackered and I can't get the
cranks off the square tapers anymore. Afraid I'll strip out the
thread of the puller tool. Various penetrating sprays didn't
help.

From the last time the BB was replaced the bike experienced a
transport across the Atlantic on a ship which probably hasn't
helped matters.

Any tricks of the trade?


Folks, thanks for all your input. I finally got it off after taking
a wooden mallet to the wrench that was turning the puller yesterday
night. I figured if I strip the puller I'd just grind everything
off and go to Octalink or whatever. AFAIK Octalink won't need a
puller.

BTW, that puller where the thread got stripped was not a
Harborfreight deal but an expensive commercial grade version from a
professional mechanic.

And yes, I plan to re-use the cranks if possible. I tightened up
the old Shimano 600 BB. The large chain ring had almost 1/10" play
and now none. Let's see if it has some life in it. If not it'll get
replaced. Shimano offers one kind (UN26 or so) with one nut being
plastic and another with steel but more than 2x the price. Does
anyone know whether the plastic ones hold up for people who mash up
hills with some load on the bike? I mean 8-10k miles, since I don't
expect much more out of a BB anyhow.

Octalink does not work with square taper.


I know. I would have then replaced the whole works, BB assembly plus cranks.


... The plastic retaining ring
will hold up fine on a UN-whatever, although the original Shimano 600
used an asymmetrical BB, IIRC.


Yup, might be an issue. It looks symmetrical but I'll have to measure.

--
Regards, Joerg

http://www.analogconsultants.com/

"Doug Landau" wrote in message
...
On Tuesday, May 23, 2017 at 10:58:39 AM UTC-7, Ian Field wrote:
"Joerg" wrote in message
...
The BB on my steel-frame bike is knackered and I can't get the cranks
off
the square tapers anymore. Afraid I'll strip out the thread of the
puller
tool. Various penetrating sprays didn't help.

The first puller tool I bought was NFG - it was pretty rare that it
didn't
strip the thread. The one I bought from Halfords has worked OK on even
the
difficult cranks.

Most of the alternatives involve varying degrees of damage.

Hammering it is likely to destroy the BB ball bearings and cups. Heat can
work, but the cranks are usually coated and will be ruined.

If it requires extreme violence - you could damage the frame. I'd hacksaw
the ends off the spindle so I can dismantle the BB bearing and start over
with new parts.

Some copper no-seize grease on square taper reassembly might make things
easier next time.

Why Copper

Coppaslip is probably one of the best known anti-seize compounds, I have a
tub of silver coloured grease that might be zinc, lead and various other
ingredients.

On 5/23/2017 2:27 PM, Ian Field wrote:


"Doug Landau" wrote in message
...
On Tuesday, May 23, 2017 at 10:58:39 AM UTC-7, Ian Field
wrote:
"Joerg" wrote in message
...
The BB on my steel-frame bike is knackered and I can't
get the cranks off
the square tapers anymore. Afraid I'll strip out the
thread of the puller
tool. Various penetrating sprays didn't help.

The first puller tool I bought was NFG - it was pretty
rare that it didn't
strip the thread. The one I bought from Halfords has
worked OK on even the
difficult cranks.

Most of the alternatives involve varying degrees of damage.

Hammering it is likely to destroy the BB ball bearings
and cups. Heat can
work, but the cranks are usually coated and will be ruined.

If it requires extreme violence - you could damage the
frame. I'd hacksaw
the ends off the spindle so I can dismantle the BB
bearing and start over
with new parts.

Some copper no-seize grease on square taper reassembly
might make things
easier next time.

Why Copper

Coppaslip is probably one of the best known anti-seize
compounds, I have a tub of silver coloured grease that might
be zinc, lead and various other ingredients.

Usually molybdenum when it isn't copper based. Either is
good for anticorrosive protection.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Tuesday, May 23, 2017 at 12:27:33 PM UTC-7, Ian Field wrote:
"Doug Landau" wrote in message
...
On Tuesday, May 23, 2017 at 10:58:39 AM UTC-7, Ian Field wrote:
"Joerg" wrote in message
...
The BB on my steel-frame bike is knackered and I can't get the cranks
off
the square tapers anymore. Afraid I'll strip out the thread of the
puller
tool. Various penetrating sprays didn't help.

The first puller tool I bought was NFG - it was pretty rare that it
didn't
strip the thread. The one I bought from Halfords has worked OK on even
the
difficult cranks.

Most of the alternatives involve varying degrees of damage.

Hammering it is likely to destroy the BB ball bearings and cups. Heat can
work, but the cranks are usually coated and will be ruined.

If it requires extreme violence - you could damage the frame. I'd hacksaw
the ends off the spindle so I can dismantle the BB bearing and start over
with new parts.

Some copper no-seize grease on square taper reassembly might make things
easier next time.

Why Copper

Coppaslip is probably one of the best known anti-seize compounds, I have a
tub of silver coloured grease that might be zinc, lead and various other
ingredients.

But it has no aluminum to give up to the reaction so the crank doesn't have to.