BB Shell Cracked! Is this just what folders do, with a 210 lb rider?

[Jay]

"Donald Gillies" <[email protected]> wrote in message
news:[email protected]...
> [email protected] (Donald Gillies) writes:
>
>>Jay <[email protected]> writes:
>
>>>On the way to work this morning, I noticed my BB shell is cracked on
>>>my BF folder:
>
>>>http://orion.neiu.edu/~jbollyn/bike/bb_shell/
>
>>I wonder if anyone bothered to look at the pictures ??
>
> After looking a 2nd time, I do agree that the BB shell looks
> crazy-thin for a suspension bike carrying a 200+ lbs rider. The crack
> started near the welds, so over-heating is also a possibility. So, it
> might be that they selected a too-thin shell, got a bum shell, or made
> the shell brittle or too distorted during welding, or some combination
> of these four possibilities.
>
> I would send them an email and ask what they think would be the
> appropriate way to solve the problem, looking for "thicker shell" as
> the correct answer for 3 out of 4 of the possible causes (the 4th, q/a
> at the shell maker, wouldn't necessarily be solved by a thicker shell.)
>
> - Don Gillies
> San Diego, CA, USA
>
>
Thanks Don, your detailed expert comments have been very helpful!

That was what I was trying to get at, comparing my folder with my new
Electra. In terms of simply raw frame component strength (and design built
to last) there is absolutely no comparison. This is obvious to even my
clueless bike-design eyes. (LO can verify how clueless I am.)

I think 'crazy-thin' is the perfect description of my folder BB shell. This
was *supposed* to be, in BF's paraphrased words, 'customized for my height
and weight'. And the head tube of this 'custom frame', is now ovalized,
after 1 year (5,000 miles). My LBS (Performance Bike retail store) says BF
admited to them on the phone, BF made a mistake, and gave me a 1" head tube,
instead of a stronger 1 1/8" head tube. I don't even know if 1 1/8" is
strong enough, but that is for RBT bike design guys to determine.

I am looking forward to my BF gathering dust in the corner on my garage, as
my rarely-used spare bike.

This BF was not cheap to me. I bought LOTS of stuff to replace the OEM junk
that was unsatisfactory for Chicago year-round commuting (which BF well knew
up front). But I have learned a lot about bike design and maintenance from
the RBT experts. Hey, I already have a job! I don't want a 2nd career as a
bike mechanic trainee! My current job keeps me plenty busy!

OK...I am just tired of typing...

J.

 

[Michael Press]

In article <[email protected]>,
"Jay" <[email protected]> wrote:

> "John Thompson" <[email protected]> wrote in message
> news:[email protected]...
> > On 2008-03-11, Donald Gillies <[email protected]> wrote:
> >
> >> I wonder if anyone bothered to look at the pictures ??
> >>
> >> That looks like a crack that started in the bottom bracket shell,
> >> perhaps as a result of over-tighening the left-side cup.
> >
> > It looked to me like the crack started in the heat-affected zone where
> > the stay bracket was attached to the shell.
> >
> I tried to take the most helpful pics I could, but I confess, I have not yet
> bought studio lighting stuff for taking bike pics. For a couple hundred USD,
> I could set up a nice little bike photo studio. I have been too lazy and
> cheap to do this. For this, I apologize.
>
> Would additional pics be helpful? I could probably jerry-rig some amateur
> lighting.
>
> I don't want to come across as clueless, when I email BF. I wanted to get
> RBT expert opinions first, because we all know that I am
> bike-design-clueless.

Those pictures are excellent, and show great detail.
For instance, the crack has been there for some time;
weeks or months. Obviously, I do not know what more
light at a grazing angle will show of the fracture.

--
Michael Press

 

[Jay]

"Michael Press" <[email protected]> wrote in message
news:[email protected]...
>
> Those pictures are excellent, and show great detail.
> For instance, the crack has been there for some time;
> weeks or months. Obviously, I do not know what more
> light at a grazing angle will show of the fracture.
>
> --
> Michael Press
>
>
> I did feel a slight bounce in the frame while riding, but that was perhaps
> one week prior. Not months. I thought - am I just imagining it? You know
> how that goes. The rider really does not want to think his year-old bike
> frame is dissolving under his bum.

I am pretty ticked off about this, in case you can't tell.

J.

 

[A Muzi]

>> Donald Gillies <[email protected]> wrote:
>>> I wonder if anyone bothered to look at the pictures ??
>>> That looks like a crack that started in the bottom bracket shell,
>>> perhaps as a result of over-tighening the left-side cup.

> "John Thompson" <[email protected]> wrote
>> It looked to me like the crack started in the heat-affected zone where
>> the stay bracket was attached to the shell.
>> John ([email protected])

Jay wrote:
> I tried to take the most helpful pics I could, but I confess, I have not yet
> bought studio lighting stuff for taking bike pics. For a couple hundred USD,
> I could set up a nice little bike photo studio. I have been too lazy and
> cheap to do this. For this, I apologize.
> Would additional pics be helpful? I could probably jerry-rig some amateur
> lighting.
> I don't want to come across as clueless, when I email BF. I wanted to get
> RBT expert opinions first, because we all know that I am
> bike-design-clueless.

You're the original owner and it was a custom. It failed. Contact the
builder and go from there.

As I suggested earlier every single thing has some measurable failure
rate. Let Green Gear handle it. No amount of speculation on our part is
helpful until or unless they disallow the warranty. But I bet they will
take care of you.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[A Muzi]

>>> Jay <[email protected]> writes:
>>>> On the way to work this morning, I noticed my BB shell is cracked on
>>>> my BF folder:
>>>> http://orion.neiu.edu/~jbollyn/bike/bb_shell/

>> [email protected] (Donald Gillies) writes:
>>> I wonder if anyone bothered to look at the pictures ??

> "Donald Gillies" <[email protected]> wrote
>> After looking a 2nd time, I do agree that the BB shell looks
>> crazy-thin for a suspension bike carrying a 200+ lbs rider. The crack
>> started near the welds, so over-heating is also a possibility. So, it
>> might be that they selected a too-thin shell, got a bum shell, or made
>> the shell brittle or too distorted during welding, or some combination
>> of these four possibilities.
>> I would send them an email and ask what they think would be the
>> appropriate way to solve the problem, looking for "thicker shell" as
>> the correct answer for 3 out of 4 of the possible causes (the 4th, q/a
>> at the shell maker, wouldn't necessarily be solved by a thicker shell.)

Jay wrote:
> Thanks Don, your detailed expert comments have been very helpful!
> That was what I was trying to get at, comparing my folder with my new
> Electra. In terms of simply raw frame component strength (and design built
> to last) there is absolutely no comparison. This is obvious to even my
> clueless bike-design eyes. (LO can verify how clueless I am.)
> I think 'crazy-thin' is the perfect description of my folder BB shell. This
> was *supposed* to be, in BF's paraphrased words, 'customized for my height
> and weight'. And the head tube of this 'custom frame', is now ovalized,
> after 1 year (5,000 miles). My LBS (Performance Bike retail store) says BF
> admited to them on the phone, BF made a mistake, and gave me a 1" head tube,
> instead of a stronger 1 1/8" head tube. I don't even know if 1 1/8" is
> strong enough, but that is for RBT bike design guys to determine.
> I am looking forward to my BF gathering dust in the corner on my garage, as
> my rarely-used spare bike.
> This BF was not cheap to me. I bought LOTS of stuff to replace the OEM junk
> that was unsatisfactory for Chicago year-round commuting (which BF well knew
> up front). But I have learned a lot about bike design and maintenance from
> the RBT experts. Hey, I already have a job! I don't want a 2nd career as a
> bike mechanic trainee! My current job keeps me plenty busy!
> OK...I am just tired of typing...

The material isn't any thinner than the steel shells used in millions of
bikes which did not break. Just get Green Gear on this and don't worry.

Every single thing has a failure rate. Give them a chance to make it
right for you. If for some reason they don't, then we can all rehash
the situation and pursue the finer points.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[jim beam]

Jay wrote:
> On the way to work this morning, I noticed my BB shell is cracked on
> my BF folder:
>
> http://orion.neiu.edu/~jbollyn/bike/bb_shell/
>
> Regular RBTers know, I often carry 20-30 lbs cargo, 3 or 4 miles. This
> frame is one year old, ~ 5,000 miles, commuting on city streets. I do
> not jump off curbs, or anything like that. Is this the kind of damage
> which can be expected with a folding bike, under this load? Or is this
> frame defective (bad steel, something like that). Or is this
> particular folder frame design simply undersized for the load?

probably - you're at the upper end of the weight range and that's not an
insignificant cargo.

bottom line, that weld failed in the heat affected zone. i think
there's a good chance that another bb of the same design and
construction will also fail in the same conditions.

i suggest using a conventional bike.



>
> I wanted to get the RBT experts opinion before breaking the bad news
> to BikeFriday. They do warranty their frames for life, so I don't
> expect a problem with them. But I am beginning to wonder if they know
> how to build a custom folding frame, strong enough for the load. They
> knew my weight and cargo beforehand, from many emails.
>
> Thanks guys.
>
> J.

 

[John Thompson]

On 2008-03-12, Jay <[email protected]> wrote:

> I tried to take the most helpful pics I could, but I confess, I have not yet
> bought studio lighting stuff for taking bike pics. For a couple hundred USD,
> I could set up a nice little bike photo studio. I have been too lazy and
> cheap to do this. For this, I apologize.
>
> Would additional pics be helpful? I could probably jerry-rig some amateur
> lighting.

No. The only opinion that will really matter in the end is that of the
BF warranty inspector, and they're going to want to see it in person
before passing judgement (speaking here as a former Trek warranty
inspector). Have your LBS send it back to them and see what they say.

--

John ([email protected])

 

[Jay]

"A Muzi" <[email protected]> wrote in message
news:[email protected]...
>
> The material isn't any thinner than the steel shells used in millions of
> bikes which did not break. Just get Green Gear on this and don't worry.
>
> Every single thing has a failure rate. Give them a chance to make it right
> for you. If for some reason they don't, then we can all rehash the
> situation and pursue the finer points.
> --
> Andrew Muzi
> www.yellowjersey.org
> Open every day since 1 April, 1971
>
>
Of course, Andrew; I defer to you and the other RBT regulars, on all bike
things. But I just now, visually compared the BB shell of my new Electra,
with the failed shell on the folder. The Electra BB shell looks
significantly thicker. I don't have the proper tool to measure the thickness
of the metal. But my first impression of my Electra is, everything is
stronger, and will doubtless last much longer. Completely different intended
use, and target customer. Very different design philosophy.

My understanding is, the Electra frame is aluminum, and the folder shell is
steel. We all know the Electra is significantly heavier.

I do agree with your other point: I am confident BF will make it right. But
thanks to RBT, I clearly see the limitations of a folder, for year round
bike commuting in Chicago. I don't need a folder now, anyway. What I need is
reliability, and low maintenance cost and frequency. Fussing with an
external derailleur in Chicago's winter is death by a thousand cuts. Just
ask Tom.

The experience of riding the Electra is so different, cf. my folder. More in
a different thread later.

Former BF Customer J.

 

[Clive George]

"Jay" <[email protected]> wrote in message
news:[email protected]...

> Of course, Andrew; I defer to you and the other RBT regulars, on all bike
> things. But I just now, visually compared the BB shell of my new Electra,
> with the failed shell on the folder. The Electra BB shell looks
> significantly thicker. I don't have the proper tool to measure the
> thickness of the metal. But my first impression of my Electra is,
> everything is stronger, and will doubtless last much longer. Completely
> different intended use, and target customer. Very different design
> philosophy.
>
> My understanding is, the Electra frame is aluminum, and the folder shell
> is steel. We all know the Electra is significantly heavier.

Even on lightweight Al bikes the BB shell will be somewhat thicker than a
steel one, so your observations aren't at all surprising.

cheers,
clive

 

[Jay]

"John Thompson" <[email protected]> wrote in message
news:[email protected]...
> On 2008-03-12, Jay <[email protected]> wrote:
>
>> I tried to take the most helpful pics I could, but I confess, I have not
>> yet
>> bought studio lighting stuff for taking bike pics. For a couple hundred
>> USD,
>> I could set up a nice little bike photo studio. I have been too lazy and
>> cheap to do this. For this, I apologize.
>>
>> Would additional pics be helpful? I could probably jerry-rig some amateur
>> lighting.
>
> No. The only opinion that will really matter in the end is that of the
> BF warranty inspector, and they're going to want to see it in person
> before passing judgement (speaking here as a former Trek warranty
> inspector). Have your LBS send it back to them and see what they say.
>
> --
>
> John ([email protected])
>
>
I don't expect a problem with BF, making this right. And this BF folder
experience over the last two years has been a real learning experience.

My main reason for posting this thread, was to get RBT regulars opinions. So
I can deal with any potential questions which may arise. I hate appearing to
be clueless, but now and then, can't be avoided.

Photography is a hobby of mine, and I do fuss a bit over my digital pics.
Proper lighting is obviously crucial. When I don't have it, I get annoyed. I
always try to look at my posted pics from the *viewers* point of view.

J.

 

[Jay]

"jim beam" <[email protected]> wrote in message
news:[email protected]...
>
> probably - you're at the upper end of the weight range and that's not an
> insignificant cargo.
>
> bottom line, that weld failed in the heat affected zone. i think there's
> a good chance that another bb of the same design and construction will
> also fail in the same conditions.
>
> i suggest using a conventional bike.
>
>
That is exactly my fear. I do not want another frame exactly like this one.
I do not have the patience for frame repairs on a yearly basis.

That is why I bought the Electra.

J.

 

[Tom Sherman]

Andrew Muzi wrote:
>> "A Muzi" <[email protected]> wrote:
>>> The material isn't any thinner than the steel shells used in millions
>>> of bikes which did not break. Just get Green Gear on this and don't
>>> worry.
>>> Every single thing has a failure rate. Give them a chance to make it
>>> right for you. If for some reason they don't, then we can all rehash
>>> the situation and pursue the finer points.
>
> Jay wrote:
>> Of course, Andrew; I defer to you and the other RBT regulars, on all
>> bike things. But I just now, visually compared the BB shell of my new
>> Electra, with the failed shell on the folder. The Electra BB shell
>> looks significantly thicker. I don't have the proper tool to measure
>> the thickness of the metal. But my first impression of my Electra is,
>> everything is stronger, and will doubtless last much longer.
>> Completely different intended use, and target customer. Very different
>> design philosophy.
>> My understanding is, the Electra frame is aluminum, and the folder
>> shell is steel. We all know the Electra is significantly heavier.
>> I do agree with your other point: I am confident BF will make it
>> right. But thanks to RBT, I clearly see the limitations of a folder,
>> for year round bike commuting in Chicago. I don't need a folder now,
>> anyway. What I need is reliability, and low maintenance cost and
>> frequency. Fussing with an external derailleur in Chicago's winter is
>> death by a thousand cuts. Just ask Tom.
>> The experience of riding the Electra is so different, cf. my folder.
>> More in a different thread later.
>> Former BF Customer J.
>
> Yes, they are quite different.
> To get the same strength from an aluminum piece as from a steel piece,
> all else being equal, the aluminum one has to be 3x thicker.
>
To get the same STIFFNESS, the aluminium (alloy) section needs to be
approximately 3 times thicker than the steel section. The elastic
modulus of either material will hardly vary with alloying and heat
treatment.

However, strengths of both materials will vary greatly with alloy
content, heat treatment, work history and any other process that alters
the micro-structure.

For example, 6061-T6 aluminium alloy (Jay's Electra Amsterdam) has yield
and UTS of 276 and 310 MPa, respectively, while normalized 4130
chrome-moly steel (similar to welded parts on Jay's BF) has yield and
UTS of 435 and 670 MPa, respectively.

> A very different design (a torque on that suspension mount plate), =
> jointing technique, wheel size, etc make the two bikes hardly a case of
> 'all else being equal'.
>
> We can speculate all we want peripherally but Green Gear has used that
> design in that material successfully for some large number of iterations
> and for a long while. Maybe not how you or I would make it, but let's
> defer to them as far as a replacement or repair under warranty.

Agreed.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

 

[A Muzi]

> "A Muzi" <[email protected]> wrote:
>> The material isn't any thinner than the steel shells used in millions of
>> bikes which did not break. Just get Green Gear on this and don't worry.
>> Every single thing has a failure rate. Give them a chance to make it right
>> for you. If for some reason they don't, then we can all rehash the
>> situation and pursue the finer points.

Jay wrote:
> Of course, Andrew; I defer to you and the other RBT regulars, on all bike
> things. But I just now, visually compared the BB shell of my new Electra,
> with the failed shell on the folder. The Electra BB shell looks
> significantly thicker. I don't have the proper tool to measure the thickness
> of the metal. But my first impression of my Electra is, everything is
> stronger, and will doubtless last much longer. Completely different intended
> use, and target customer. Very different design philosophy.
> My understanding is, the Electra frame is aluminum, and the folder shell is
> steel. We all know the Electra is significantly heavier.
> I do agree with your other point: I am confident BF will make it right. But
> thanks to RBT, I clearly see the limitations of a folder, for year round
> bike commuting in Chicago. I don't need a folder now, anyway. What I need is
> reliability, and low maintenance cost and frequency. Fussing with an
> external derailleur in Chicago's winter is death by a thousand cuts. Just
> ask Tom.
> The experience of riding the Electra is so different, cf. my folder. More in
> a different thread later.
> Former BF Customer J.

Yes, they are quite different.
To get the same strength from an aluminum piece as from a steel piece,
all else being equal, the aluminum one has to be 3x thicker.

A very different design (a torque on that suspension mount plate),
jointing technique, wheel size, etc make the two bikes hardly a case of
'all else being equal'.

We can speculate all we want peripherally but Green Gear has used that
design in that material successfully for some large number of iterations
and for a long while. Maybe not how you or I would make it, but let's
defer to them as far as a replacement or repair under warranty.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

 

[Hank]

On Mar 12, 6:37 pm, A Muzi <[email protected]> wrote:

>
> Yes, they are quite different.
> To get the same strength from an aluminum piece as from a steel piece,
> all else being equal, the aluminum one has to be 3x thicker.
>


Example: bog-standard lightweight steel road frame - the top of the
seat tube is 28.6mm OD, 27.2mm ID = 0.7mm tube thickness.

Bog-standard aluminum road frame: 31.8mm OD, 27.2mm ID = 2.3mm tube
thickness.

Obviously, this will be skewed by the de facto butted reinforcement of
the seatpost, but there you go...just over 3x thicker.