BB or crank?

bomba said:

How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll probably
replace both, but was just wondering if there was scientific method for working out which is the
culprit.

Not to be snide, but the simplest solution is to replace one or the other with a known operable
piece and see if the problem persisits. Either way, you've found your culprit.

Tom

In article <[email hidden]>, myarse247 @hotmail.com says...

Quoted message said:

How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll probably
replace both, but was just wondering if there was scientific method for working out which is the
culprit.

Scientifically speaking, it's pretty much impossible to bend a BB spindle without bending the
crank arm.
--
_________________________
Chris Phillipo - Cape Breton, Nova Scotia ramsays-online.comramsays-online.comOpen ↗

bomba said:

How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll probably
replace both, but was just wondering if there was scientific method for working out which is the
culprit.

I would take the cranks off and turn the spindle looking for wiggle on both sides. When you don't
see any, you'll know you bent your crank 🙂

Shawn

In "]news:[email hidden],
bomba <[email hidden]> typed:

Quoted message said:

How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll probably
replace both, but was just wondering if there was scientific method for working out which is the
culprit.

Remove the crank and hold a fixed point (pencil or scribe) to the BB axle and turn the axle looking
for wobble. (Kinda like a truing stand) If it's not the spindle it's the cranks.

Mike

Chris Phillipo said:

In article <[email hidden]>, myarse247 @hotmail.com says...

Quoted message said:

How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll probably
replace both, but was just wondering if there was scientific method for working out which is the
culprit.

Scientifically speaking, it's pretty much impossible to bend a BB spindle without bending the
crank arm.

I thought so too but when I replaced the crank arms the wobble was still there. It became obvious
too when I looked at the BB more closely.

If the front gears sway from side to side when turning then it is the BB (or the gears, OR both). If
the pedal is not level for the entire revolution then it is the crank arm.

--
Regards, CK (remove clothes to reply)

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

Quoted message said:

Chris Phillipo said:

In article <[email hidden]>, myarse247 @hotmail.com says...

Quoted message said:

How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll probably
replace both, but was just wondering if there was scientific method for working out which is
the culprit.

Scientifically speaking, it's pretty much impossible to bend a BB spindle without bending the
crank arm.

I thought so too but when I replaced the crank arms the wobble was still there. It became obvious
too when I looked at the BB more closely.

If the front gears sway from side to side when turning then it is the BB (or the gears, OR both).
If the pedal is not level for the entire revolution then it is the crank arm.

Let me rephrase that, it's pretty much impossible to bend a BB spindle without bending the crank
arm. Hmm, maybe I can't rephrase that.
--
_________________________
Chris Phillipo - Cape Breton, Nova Scotia ramsays-online.comramsays-online.comOpen ↗

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

Quoted message said:

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

Quoted message said:

Chris Phillipo said:

In article <[email hidden]>, myarse247 @hotmail.com says...
> How can you tell if it's the BB you've bent or the cranks? Kind of irrelevant as I'll
> probably replace both, but was just wondering if there was scientific method for working out
> which is the culprit.
>
>

Scientifically speaking, it's pretty much impossible to bend a BB spindle without bending the
crank arm.

I thought so too but when I replaced the crank arms the wobble was still there. It became
obvious too when I looked at the BB more closely.

If the front gears sway from side to side when turning then it is the BB (or the gears, OR
both). If the pedal is not level for the entire revolution then it is the crank arm.

Let me rephrase that, it's pretty much impossible to bend a BB spindle without bending the crank
arm. Hmm, maybe I can't rephrase that.
--

However you phrase it, in the real world its possible - I snapped an XT square taper bb off on the
drive side, the mid 90's? XTR cranks are still going strong.

Steve.

spademan o---) * said:

Quoted message said:

Let me rephrase that, it's pretty much impossible to bend a BB spindle without bending the crank
arm. Hmm, maybe I can't rephrase that.

However you phrase it, in the real world its possible - I snapped an XT square taper bb off on the
drive side, the mid 90's? XTR cranks are still going strong.

Hmm, I was beginning to doubt my memory. I bent a couple of UN-72s in the mid-90's (when I was going
through my jumping phase), but the XT cranks seemed to be ok.

--
a.m-b FAQ: j-harris.netambfaq.htmOpen ↗

b.bmx FAQ: t-online.debmx faq.htmOpen ↗

Quoted message said:

Quoted message said:

Quoted message said:

revolution then it is the crank arm.

Let me rephrase that, it's pretty much impossible to bend a BB spindle without bending the crank
arm. Hmm, maybe I can't rephrase that.
--

However you phrase it, in the real world its possible - I snapped an XT square taper bb off on the
drive side, the mid 90's? XTR cranks are still going strong.

Steve.

What I'm saying is, if you have a bent B spindle you have a bent crank arm also. So it's not a
question of replacing either or. It's both.
--
_________________________
Chris Phillipo - Cape Breton, Nova Scotia ramsays-online.comramsays-online.comOpen ↗

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

Quoted message said:

Quoted message said:

Quoted message said:

> revolution then it is the crank arm.
>
>

Let me rephrase that, it's pretty much impossible to bend a BB spindle without bending the
crank arm. Hmm, maybe I can't rephrase that.
--

However you phrase it, in the real world its possible - I snapped an XT square taper bb off on
the drive side, the mid 90's? XTR cranks are

still

Quoted message said:

Quoted message said:

going strong.

Steve.

What I'm saying is, if you have a bent B spindle you have a bent crank arm also. So it's not a
question of replacing either or. It's both.

explain that one more time? I replaced my BB and re-fitted the same cranks...voila.

Steve.

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

Quoted message said:

spademan o---) * said:

Quoted message said:

Let me rephrase that, it's pretty much impossible to bend a BB spindle without bending the
crank arm. Hmm, maybe I can't rephrase that.

However you phrase it, in the real world its possible - I snapped an XT square taper bb off on
the drive side, the mid 90's? XTR cranks are

still

Quoted message said:

Quoted message said:

going strong.

Hmm, I was beginning to doubt my memory. I bent a couple of UN-72s in the mid-90's (when I was
going through my jumping phase), but the XT cranks seemed to be ok.

It didn't seem to appreciate hanging up on a rock hard BMX track double... as we had driven some way
to get there much fun was spent the rest of the day one-footing it round a BMX track. You can
surprisingly still bunny-hop and although it was slightly downhill carrying momentum was a problem.

Steve.

Quoted message said:

Quoted message said:

Quoted message said:

> --

However you phrase it, in the real world its possible - I snapped an XT square taper bb off on
the drive side, the mid 90's? XTR cranks are

still

Quoted message said:

Quoted message said:

going strong.

Steve.

What I'm saying is, if you have a bent B spindle you have a bent crank arm also. So it's not a
question of replacing either or. It's both.

explain that one more time? I replaced my BB and re-fitted the same cranks...voila.

Steve.

You said you broke yours, not bent it. Defective spindles snap off with less force than is required
to bend a good one.
--
_________________________
Chris Phillipo - Cape Breton, Nova Scotia ramsays-online.comramsays-online.comOpen ↗

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

Quoted message said:

Quoted message said:

Quoted message said:

> > --
>
> However you phrase it, in the real world its possible - I snapped an

XT

Quoted message said:

Quoted message said:

Quoted message said:

> square taper bb off on the drive side, the mid 90's? XTR cranks are

still

Quoted message said:

> going strong.
>
> Steve.
>

What I'm saying is, if you have a bent B spindle you have a bent crank arm also. So it's not a
question of replacing either or. It's both.

explain that one more time? I replaced my BB and re-fitted the same cranks...voila.

Steve.

You said you broke yours, not bent it. Defective spindles snap off with less force than is
required to bend a good one.

Are you a lawyer? actually s'fair point just a little bit nit-picky...

Steve.

In article <[email hidden]>, "spademan o---[\) *"
<[email hidden]> says...

Quoted message said:

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

Quoted message said:

Quoted message said:

> > > --
> >
> > However you phrase it, in the real world its possible - I snapped an

XT

Quoted message said:

Quoted message said:

> > square taper bb off on the drive side, the mid 90's? XTR cranks are
still
> > going strong.
> >
> > Steve.
> >
>
> What I'm saying is, if you have a bent B spindle you have a bent crank arm also. So it's not
> a question of replacing either or. It's both.

explain that one more time? I replaced my BB and re-fitted the same cranks...voila.

Steve.

You said you broke yours, not bent it. Defective spindles snap off with less force than is
required to bend a good one.

Are you a lawyer? actually s'fair point just a little bit nit-picky...

Steve.

The guy said he thinks he bent either his spindle or his crank, I simply informed him that it's only
a question of wether the spindle is bent because the crank arm almost certainly is. You anecdote
about snapping a spindle really does not apply.
--
_________________________
Chris Phillipo - Cape Breton, Nova Scotia ramsays-online.comramsays-online.comOpen ↗

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

Quoted message said:

In article <[email hidden]>, "spademan o---[\) *"
<[email hidden]> says...

Quoted message said:

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

Quoted message said:

> > > > --
> > >
> > > However you phrase it, in the real world its possible - I

snapped an

Quoted message said:

Quoted message said:

XT

Quoted message said:

> > > square taper bb off on the drive side, the mid 90's? XTR cranks

are

Quoted message said:

Quoted message said:

Quoted message said:

> still
> > > going strong.
> > >
> > > Steve.
> > >
> >
> > What I'm saying is, if you have a bent B spindle you have a bent

crank

Quoted message said:

Quoted message said:

Quoted message said:

> > arm also. So it's not a question of replacing either or. It's

both.

Quoted message said:

Quoted message said:

Quoted message said:

>
> explain that one more time? I replaced my BB and re-fitted the same cranks...voila.
>
> Steve.
>
>
>

You said you broke yours, not bent it. Defective spindles snap off

with

Quoted message said:

Quoted message said:

Quoted message said:

less force than is required to bend a good one.

Are you a lawyer? actually s'fair point just a little bit nit-picky...

Steve.

The guy said he thinks he bent either his spindle or his crank, I simply informed him that it's
only a question of wether the spindle is bent because the crank arm almost certainly is. You
anecdote about snapping a spindle really does not apply.
--

I am sorry. I will keep my anacdotes to myself in future <hangs head in shame