Knackered crank?

"NickD" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts....

-Probably
-No
-Probably just Crank, but a new BB wouldn't hurt.

And I dunno if it was over-tightening that caused it, but what usually kills
an arm is noticing the looseness and not getting off the bike immediately.
Often, even then it's too late.

Good luck!

NickD said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Is this an Octalink crank and BB, or the new kind with the BB axle as part
of the right crank, and the left crank held on with a pinch bolt?

Matt O.

Matt O'Toole said:

NickD said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the
non-drive crank to creak and flex on the BB; turning them round (so
that the right crank is at the back, left crank at the front) and
standing on the pedals causes the left crank to creak and flex back
the other way...

Is this an Octalink crank and BB, or the new kind with the BB axle as
part of the right crank, and the left crank held on with a pinch bolt?

Matt O.

The OP said, "LX Hollowtech (I)" which implies Octalink.
--
Phil, Squid-in-Training

NickD said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts....

Octalink BB, no? IMO, you probably didn't do any damage by tightening
the bolts periodically, but did you tighten them *enough*? That
interface design has issues. (Some would say it has entire bound
volumes going back to 1982.) Once the motion in the left crank gets
to the point of being noticeable, it's pretty much toast, though if
you have a good puller, you might be able to get a little more use
from it by applying red LocTite to the splines and reassembling. One
thing's for sure; you have little to lose by trying the LocTite, as
the left arm's pretty much scrap now.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Nick Drew said:

Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB.
Essentially, the crank loosens itself over the space of 3 (road)
miles, with creaking and 'slip' (I can feel the crank shifting
minutely before it starts to actually engage). I have a suspicion
(from reading around now) that I may have b*ggered it by tightening
up the crank bolt periodically. Essentially, standing on the pedals
causes the non-drive crank to creak and flex on the BB; turning them
round (so that the right crank is at the back, left crank at the
front) and standing on the pedals causes the left crank to creak and
flex back the other way...

Your description doesn't give a clear picture of what is happening.
How far does the left crank rotate with respect to a fixed position
for the right crank? To test this, stand on the pedals with the
cranks horizontal, the left crank to the rear and lunge on them to
take up any backlash. Then gently rotate the cranks (backward) until
the left crank is straight forward and, with the rear brake held
firmly, push down hard on left the crank. Do this in a big gear
(little rear sprocket).

This should give you a clear picture of how badly the crank attachment
is damaged without disassembling anything. However, you should pull
off both cranks and inspect the Octalink spline in the cranks that
will most likely have a clearly damages profile. The splines should
be smooth straight through slots without steps in their flanks.

Quoted message said:

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Most likely new cranks because this affects both ends. The spindle is
steel and doesn't suffer from this. The problem is that if you often
coast standing, with the right pedal forward, the retaining nut will
unscrew from backlash movement in the spline. Riders who always coast
standing with the left foot forward, don't have this problem because
this never causes reverse torque in the spindle.

Quoted message said:

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts...

Not at all. It is a Shimano design error and that is why their new
cranks have a different spindle attachment, the right being permanent
and the left using two pinch bolts for a no-backlash spline.

Jobst Brandt

Werehatrack said:

On 3 Apr 2006 06:27:55 -0700, "NickD" <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts....

Quoted message said:

Octalink BB, no? IMO, you probably didn't do any damage by tightening
the bolts periodically, but did you tighten them *enough*?

This is the problem. Octalink crank bolts have fine threads (lots of
friction), and often feel tight enough when they're not. So clean
everything thoroughly, especially the threads, lubricate with grease, and
reassemble *with a torque wrench.* Torque specs are available at the Park
Tool site.

If you still have problems after doing this, your crank is probably
a goner. But don't assume anything until you know it's been installed
properly.

I've had my cranks installed improperly three times by supposedly
professional mechanics. After re-doing them myself I've had no
problems.

You shouldn't need to re-torque these cranks. If you can do it at all,
you didn't have them tight enough to begin with. They can't lever
themselves up a taper like the square taper ones do, which are then
damaged by re-tightening.

Matt O.

NickD said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts....

Cheers
Nick

One or both crankarms are probably trashed. Splined cranks (like yours)
aren't prone to the kind of death-by-repeated-tightening you're
probably talking about. They more or less just bottom out firmly on the
spindle when they're installed, and torquing to proper tightness should
keep them there. If the crank bolt ever came loose after that and the
bike was ridden with the crank loose, that can (and does) kill cranks.
It's also possible to damage Octalink cranks by making a somewhat
common mistake during installation where the splines are jammed into
each other and feel engaged but aren't, and you can't see it happening
because the self extractor is in the way.

Take off the cranks (the loose one will probably just fall off -
hopefully the other one will require you to use it's self extractor or
a tool) and look at the splines on the cranks and the bottom bracket.
They should be pretty perfect looking.

Sometimes this happens and the bottom bracket spindle is still fine,
presumably because it's made out of hardened steel and the cranks are
aluminum, but it's often trashed as well. Probably in all cases it
won't *look* as trashed as the spline interface on the cranks, but
basically any damage to the splines at all calls for a replacement.

Quoted message said:

Nick Drew said:

Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB.
Essentially, the crank loosens itself over the space of 3 (road)
miles, with creaking and 'slip' (I can feel the crank shifting
minutely before it starts to actually engage). I have a suspicion
(from reading around now) that I may have b*ggered it by tightening
up the crank bolt periodically. Essentially, standing on the pedals
causes the non-drive crank to creak and flex on the BB; turning them
round (so that the right crank is at the back, left crank at the
front) and standing on the pedals causes the left crank to creak and
flex back the other way...

Your description doesn't give a clear picture of what is happening.
How far does the left crank rotate with respect to a fixed position
for the right crank? To test this, stand on the pedals with the
cranks horizontal, the left crank to the rear and lunge on them to
take up any backlash. Then gently rotate the cranks (backward) until
the left crank is straight forward and, with the rear brake held
firmly, push down hard on left the crank. Do this in a big gear
(little rear sprocket).

This should give you a clear picture of how badly the crank attachment
is damaged without disassembling anything. However, you should pull
off both cranks and inspect the Octalink spline in the cranks that
will most likely have a clearly damages profile. The splines should
be smooth straight through slots without steps in their flanks.

Quoted message said:

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Most likely new cranks because this affects both ends. The spindle is
steel and doesn't suffer from this. The problem is that if you often
coast standing, with the right pedal forward, the retaining nut will
unscrew from backlash movement in the spline. Riders who always coast
standing with the left foot forward, don't have this problem because
this never causes reverse torque in the spindle.

Could you elaborate on this? Are you saying that the crank bolt
gradually unscrews because there's some kind of tiny slop in the
splined interface? I don't get it.

Quoted message said:

Quoted message said:

Quoted message said:

Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB.
Essentially, the crank loosens itself over the space of 3 (road)
miles, with creaking and 'slip' (I can feel the crank shifting
minutely before it starts to actually engage). I have a suspicion
(from reading around now) that I may have b*ggered it by tightening
up the crank bolt periodically. Essentially, standing on the pedals
causes the non-drive crank to creak and flex on the BB; turning them
round (so that the right crank is at the back, left crank at the
front) and standing on the pedals causes the left crank to creak and
flex back the other way...

I think it may be one of two things:

1. If the crank is ruined, it may have happened because it was
installed a bit off from the proper seat on the spindle. If this
happens the crank teeth may get worn and stop holding the crank in
place. OR,

2. it could just be the bottom bracket. My Dura Ace cranks started
creeking and loosening on me, so I thought I might as well replace the
less expensive bottom bracket first. Sure enough, the bottom bracket
was worn and wobbling and was causing the crank bolt to loosen.

Another thing may be to just remove the crank and BB, re0install with
the full grease treatment. I now have a Dura Ace BB, and I have to do
that periodically to keep it quiet.

--keven.

Nate Knutson said:

Quoted message said:

Quoted message said:

Recently I've been having issues with the non-drive side crank on
my Kona hardtail. It's an LX Hollowtech (I) crank on LX BB.
Essentially, the crank loosens itself over the space of 3 (road)
miles, with creaking and 'slip' (I can feel the crank shifting
minutely before it starts to actually engage). I have a suspicion
(from reading around now) that I may have buggered it by
tightening up the crank bolt periodically. Essentially, standing
on the pedals causes the non-drive crank to creak and flex on the
BB; turning them round (so that the right crank is at the back,
left crank at the front) and standing on the pedals causes the
left crank to creak and flex back the other way...

Quoted message said:

Quoted message said:

Your description doesn't give a clear picture of what is happening.
How far does the left crank rotate with respect to a fixed position
for the right crank? To test this, stand on the pedals with the
cranks horizontal, the left crank to the rear and lunge on them to
take up any backlash. Then gently rotate the cranks (backward)
until the left crank is straight forward and, with the rear brake
held firmly, push down hard on left the crank. Do this in a big
gear (little rear sprocket).

Quoted message said:

Quoted message said:

This should give you a clear picture of how badly the crank
attachment is damaged without disassembling anything. However, you
should pull off both cranks and inspect the Octalink spline in the
cranks that will most likely have a clearly damages profile. The
splines should be smooth straight through slots without steps in
their flanks.

Quoted message said:

Quoted message said:

Quoted message said:

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Quoted message said:

Quoted message said:

Most likely new cranks because this affects both ends. The spindle
is steel and doesn't suffer from this. The problem is that if you
often coast standing, with the right pedal forward, the retaining
nut will unscrew from backlash movement in the spline. Riders who
always coast standing with the left foot forward, don't have this
problem because this never causes reverse torque in the spindle.

Quoted message said:

Could you elaborate on this? Are you saying that the crank bolt
gradually unscrews because there's some kind of tiny slop in the
splined interface? I don't get it.

http://www.sheldonbrown.com/brandt/loosening-cranks.html

Jobst Brandt

Matt O'Toole said:

Quoted message said:

Quoted message said:

Recently I've been having issues with the non-drive side crank on
my Kona hardtail. It's an LX Hollowtech (I) crank on LX
BB. Essentially, the crank loosens itself over the space of 3
(road) miles, with creaking and 'slip' (I can feel the crank
shifting minutely before it starts to actually engage). I have a
suspicion (from reading around now) that I may have buggered it by
tightening up the crank bolt periodically. Essentially, standing
on the pedals causes the non-drive crank to creak and flex on the
BB; turning them round (so that the right crank is at the back,
left crank at the front) and standing on the pedals causes the
left crank to creak and flex back the other way...

Quoted message said:

Quoted message said:

Quoted message said:

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Quoted message said:

Quoted message said:

Quoted message said:

Be gentle - I've only just discovered that I may well have done
the damage myself by tightening the bolts...

Quoted message said:

Quoted message said:

Octalink BB, no? IMO, you probably didn't do any damage by
tightening the bolts periodically, but did you tighten them
*enough*?

Quoted message said:

This is the problem. Octalink crank bolts have fine threads (lots
of friction), and often feel tight enough when they're not. So
clean everything thoroughly, especially the threads, lubricate with
grease, and reassemble *with a torque wrench.* Torque specs are
available at the Park Tool site.

Quoted message said:

If you still have problems after doing this, your crank is probably
a goner. But don't assume anything until you know it's been
installed properly.

Quoted message said:

I've had my cranks installed improperly three times by supposedly
professional mechanics. After re-doing them myself I've had no
problems.

Quoted message said:

You shouldn't need to re-torque these cranks. If you can do it at
all, you didn't have them tight enough to begin with. They can't
lever themselves up a taper like the square taper ones do, which are
then damaged by re-tightening.

Not if you are "goofy footed" (stand with the right foot forward).
The spline is not a press fit (on its flanks) and therefore has
clearance from required assembly tolerance that together with elastic
backlash, is enough to microscopically turn the retaining screw. That
screw will not tighten itself from this motion. It will unscrew and
the crank will follow, keepig it tight looking. Because the crank
has a solid cylindrical fit on the spindle, the rider notices nothing
until there is so little spline engagement that the aluminum shears.

Shimano was so unaware of this that they made a second version that
had deeper splines, believing that they had too little engagement.
That only occurred when the retaining screw backed out.

Shimano didn't scrap that idea for nothing. We have spent a few years
reading about failed Octalink here, and I have written about it
often.

Jobst Brandt

Quoted message said:

Nick Drew said:

Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB.
Essentially, the crank loosens itself over the space of 3 (road)
miles, with creaking and 'slip' (I can feel the crank shifting
minutely before it starts to actually engage). I have a suspicion
(from reading around now) that I may have b*ggered it by tightening
up the crank bolt periodically. Essentially, standing on the pedals
causes the non-drive crank to creak and flex on the BB; turning them
round (so that the right crank is at the back, left crank at the
front) and standing on the pedals causes the left crank to creak and
flex back the other way...

Your description doesn't give a clear picture of what is happening.
How far does the left crank rotate with respect to a fixed position
for the right crank? To test this, stand on the pedals with the
cranks horizontal, the left crank to the rear and lunge on them to
take up any backlash. Then gently rotate the cranks (backward) until
the left crank is straight forward and, with the rear brake held
firmly, push down hard on left the crank. Do this in a big gear
(little rear sprocket).

This should give you a clear picture of how badly the crank attachment
is damaged without disassembling anything. However, you should pull
off both cranks and inspect the Octalink spline in the cranks that
will most likely have a clearly damages profile. The splines should
be smooth straight through slots without steps in their flanks.

Quoted message said:

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Most likely new cranks because this affects both ends. The spindle is
steel and doesn't suffer from this. The problem is that if you often
coast standing, with the right pedal forward, the retaining nut will
unscrew from backlash movement in the spline. Riders who always coast
standing with the left foot forward, don't have this problem because
this never causes reverse torque in the spindle.

Quoted message said:

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts...

Not at all. It is a Shimano design error and that is why their new
cranks have a different spindle attachment, the right being permanent
and the left using two pinch bolts for a no-backlash spline.

Others will claim that the reason their new cranks have a different spindle
attachment is because the Bullseye crank patent ran out.
--
Phil, Squid-in-Training

Nate Knutson said:

Quoted message said:

Nick Drew said:

Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB.
Essentially, the crank loosens itself over the space of 3 (road)
miles, with creaking and 'slip' (I can feel the crank shifting
minutely before it starts to actually engage). I have a suspicion
(from reading around now) that I may have b*ggered it by tightening
up the crank bolt periodically. Essentially, standing on the pedals
causes the non-drive crank to creak and flex on the BB; turning them
round (so that the right crank is at the back, left crank at the
front) and standing on the pedals causes the left crank to creak and
flex back the other way...

Your description doesn't give a clear picture of what is happening.
How far does the left crank rotate with respect to a fixed position
for the right crank? To test this, stand on the pedals with the
cranks horizontal, the left crank to the rear and lunge on them to
take up any backlash. Then gently rotate the cranks (backward) until
the left crank is straight forward and, with the rear brake held
firmly, push down hard on left the crank. Do this in a big gear
(little rear sprocket).

This should give you a clear picture of how badly the crank attachment
is damaged without disassembling anything. However, you should pull
off both cranks and inspect the Octalink spline in the cranks that
will most likely have a clearly damages profile. The splines should
be smooth straight through slots without steps in their flanks.

Quoted message said:

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Most likely new cranks because this affects both ends. The spindle is
steel and doesn't suffer from this. The problem is that if you often
coast standing, with the right pedal forward, the retaining nut will
unscrew from backlash movement in the spline. Riders who always coast
standing with the left foot forward, don't have this problem because
this never causes reverse torque in the spindle.

Could you elaborate on this? Are you saying that the crank bolt
gradually unscrews because there's some kind of tiny slop in the
splined interface? I don't get it.

that's because jobst, as usual, hasn't thought this through or bothered
to examine the interface for /all/ relevant detail. the bottom of the
spline grooves are radiused. this has the effect of wedging the parts
tight and they're /not/ free to float in a jobstian way unless the bolt
is loose.

jobst's bleating about shimano "redesigning" to "fix" a problem is utter
hogwash. the hollowtech II interface has parallel splines so is just as
able to lash as any other parallel splined interface. and the real
reason the interface changed is that the crank is now so large and thin
walled, traditional bolting causes serious distortion problems.

Quoted message said:

Matt O'Toole said:

Quoted message said:

>Recently I've been having issues with the non-drive side crank on
>my Kona hardtail. It's an LX Hollowtech (I) crank on LX
>BB. Essentially, the crank loosens itself over the space of 3
>(road) miles, with creaking and 'slip' (I can feel the crank
>shifting minutely before it starts to actually engage). I have a
>suspicion (from reading around now) that I may have buggered it by
>tightening up the crank bolt periodically. Essentially, standing
>on the pedals causes the non-drive crank to creak and flex on the
>BB; turning them round (so that the right crank is at the back,
>left crank at the front) and standing on the pedals causes the
>left crank to creak and flex back the other way...

Quoted message said:

Quoted message said:

>Questions
>- Is it fubar'd?
>- Can it be fixed?
>- or does it need a new BB/ crank/ both?

Quoted message said:

Quoted message said:

>Be gentle - I've only just discovered that I may well have done
>the damage myself by tightening the bolts...

Quoted message said:

Quoted message said:

Octalink BB, no? IMO, you probably didn't do any damage by
tightening the bolts periodically, but did you tighten them
*enough*?

Quoted message said:

This is the problem. Octalink crank bolts have fine threads (lots
of friction), and often feel tight enough when they're not. So
clean everything thoroughly, especially the threads, lubricate with
grease, and reassemble *with a torque wrench.* Torque specs are
available at the Park Tool site.

Quoted message said:

If you still have problems after doing this, your crank is probably
a goner. But don't assume anything until you know it's been
installed properly.

Quoted message said:

I've had my cranks installed improperly three times by supposedly
professional mechanics. After re-doing them myself I've had no
problems.

Quoted message said:

You shouldn't need to re-torque these cranks. If you can do it at
all, you didn't have them tight enough to begin with. They can't
lever themselves up a taper like the square taper ones do, which are
then damaged by re-tightening.

Not if you are "goofy footed" (stand with the right foot forward).
The spline is not a press fit (on its flanks) and therefore has
clearance from required assembly tolerance that together with elastic
backlash, is enough to microscopically turn the retaining screw. That
screw will not tighten itself from this motion. It will unscrew and
the crank will follow, keepig it tight looking. Because the crank
has a solid cylindrical fit on the spindle, the rider notices nothing
until there is so little spline engagement that the aluminum shears.

Shimano was so unaware of this that they made a second version that
had deeper splines, believing that they had too little engagement.
That only occurred when the retaining screw backed out.

Shimano didn't scrap that idea for nothing. We have spent a few years
reading about failed Octalink here, and I have written about it
often.

Jobst Brandt

yeah, and you're just as accurate in that assessment as you are when you
repeatedly, over many years, including in print, write that you can
eliminate fatigue in a material that doesn't exhibit strain aging.

Werehatrack said:

NickD said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically.

If it's an octalink and you've had to tighten the bolt periodically it
was coming loose anyway, tightening it is probably all that kept it on
so long...

Quoted message said:

Quoted message said:

Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Questions
- Is it fubar'd?
- Can it be fixed?
- or does it need a new BB/ crank/ both?

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts....

Octalink BB, no? IMO, you probably didn't do any damage by tightening
the bolts periodically, but did you tighten them *enough*? That
interface design has issues. (Some would say it has entire bound
volumes going back to 1982.) Once the motion in the left crank gets
to the point of being noticeable, it's pretty much toast, though if
you have a good puller, you might be able to get a little more use
from it by applying red LocTite to the splines and reassembling. One
thing's for sure; you have little to lose by trying the LocTite, as
the left arm's pretty much scrap now.

I'd agree with all the above, having had the problem myself from new.
FWIW mine was (and is) cured with grease on the splines, red Loctite on
the threads and as much tightening torque as I could possibly put on
the bolt and Shimano recommendations be damned. However I didn't ride
on it while loose.

Red loctite all round would be a better bet if the crank is showing
signs of wear on the internal splines. Failing that, it probably is
toast, and rather than going with another octalink I'd either go
Hollowtech II or square taper.

NickD said:

Hi all,
Recently I've been having issues with the non-drive side crank on my
Kona hardtail. It's an LX Hollowtech (I) crank on LX BB. Essentially,
the crank loosens itself over the space of 3 (road) miles, with
creaking and 'slip' (I can feel the crank shifting minutely before it
starts to actually engage). I have a suspicion (from reading around
now) that I may have b*ggered it by tightening up the crank bolt
periodically. Essentially, standing on the pedals causes the non-drive
crank to creak and flex on the BB; turning them round (so that the
right crank is at the back, left crank at the front) and standing on
the pedals causes the left crank to creak and flex back the other
way...

Questions
- Is it fubar'd?->YES
- Can it be fixed?->NO
- or does it need a new BB/ crank/ both?_>Just a left arm, available from a bike shop that deals with Quality

Be gentle - I've only just discovered that I may well have done the
damage myself by tightening the bolts....Probably not. These do have a tendency to loosen if you jump with the left arm 'back'.That is, push the crank the opposite direction as pedaling. Samo for Octalink track cranks.

Cheers
Nick

Cheers for the replies fellas (and ladies?). Found a website that does
Shimano spares, so will try loctite for now. If that doesn't fix the
issue satisfactorily, I'll get a new non-drive crank. I'm in the
process of speccing a new hardtail frame anyway - I'll just make sure I
use a different BB and crankset in future...

Any recommendations? ISIS is made of playdoh, by all accounts. Back to
square taper?

Thanks
Nick

NickD said:

Any recommendations? ISIS is made of playdoh, by all accounts. Back to
square taper?

I went back to square on both my bikes, seems to be the best option
IMO. Honestly I don't notice any of that "flex" marketing people talk
about. Just simple and reliable.

-nate

NickD said:

Cheers for the replies fellas (and ladies?). Found a website that does
Shimano spares, so will try loctite for now. If that doesn't fix the
issue satisfactorily, I'll get a new non-drive crank. I'm in the
process of speccing a new hardtail frame anyway - I'll just make sure I
use a different BB and crankset in future...

Any recommendations? ISIS is made of playdoh, by all accounts. Back to
square taper?

Thanks
Nick

I'll warn you that to contradict what most of your replies said, I've
definitely seen splines on an ISIS BB spindle get messed up from being
ridden with the crank loose, even though the spindle is made of much
harder stuff than the crank. It wasn't dramatic in appearance but it
was certainly damage to a part that needs to be precise, and was enough
to make putting a new crank on that BB questionable at best. I don't
know if the same thing could happen with Octalink but I would assume so
unless I had reason to think otherwise.