Carbon component design news

Am 10.03.2021 um 03:57 schrieb Frank Krygowski:
On 3/9/2021 6:25 PM, AMuzi wrote:

No idea.Â* We started to remove the old tape and found it, with the two
Ergo cables, made a sorta splint holding the shattered bar in place.

I'm curious about how common handlebar breakage is. I know one guy who
broke one maybe 30 years ago. He was a masher riding a time trial bike
with brake cables inside the bar, for aerodynamics. The handlebar
snapped at the cable's exit hole in the bar when he sprinted away from a
standing stop. (Lesson: Don't drill holes in handlebars.)

I have one bar that bent a bit in a crash, and another that I retired
just based on its old age. But I can't think of anyone else I know who
actually broke one.

Anybody here besides Joerg actually break one?

I broke one when I was 5 or 6 years old, on a cheap 1970's folding bike.
The only details I remember is where the accident happened and that I
was riding on cobbles.

Rolf Mantel wrote:
Am 10.03.2021 um 03:57 schrieb Frank Krygowski:
On 3/9/2021 6:25 PM, AMuzi wrote:

No idea.* We started to remove the old tape and found it, with the two
Ergo cables, made a sorta splint holding the shattered bar in place.

I'm curious about how common handlebar breakage is. I know one guy who
broke one maybe 30 years ago. He was a masher riding a time trial bike
with brake cables inside the bar, for aerodynamics. The handlebar
snapped at the cable's exit hole in the bar when he sprinted away from a
standing stop. (Lesson: Don't drill holes in handlebars.)

I have one bar that bent a bit in a crash, and another that I retired
just based on its old age. But I can't think of anyone else I know who
actually broke one.

There must be plenty, just look at the cemeteries!

Anybody here besides Joerg actually break one?

I broke one when I was 5 or 6 years old, on a cheap 1970's folding bike.
The only details I remember is where the accident happened and that I
was riding on cobbles.

I broke one of the 1960's predecessors when pulling it while accelerating
across a road. Tought me a lesson about three decades of corrosion inside a
shiny chrome tube. Still own the heavy Japanese CroMo MTB bar I bought next.

On Tuesday, March 9, 2021 at 9:57:06 PM UTC-5, Frank Krygowski wrote:
On 3/9/2021 6:25 PM, AMuzi wrote:
On 3/9/2021 4:49 PM, jbeattie wrote:
On Tuesday, March 9, 2021 at 2:28:14 PM UTC-8, AMuzi wrote:
On 3/9/2021 3:58 PM, Tom Kunich wrote:
On Tuesday, March 9, 2021 at 1:25:04 PM UTC-8, Joerg wrote:
On 3/9/21 12:47 PM, Joerg wrote:
On 3/8/21 8:43 AM, Tom Kunich wrote:
On Monday, March 8, 2021 at 5:48:04 AM UTC-8, AMuzi wrote:
https://www.bicycleretailer.com/indu...r#.YEYq8BKNWOI


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
Canyon KNEW this was a weak spot and specifically designed a hinged
three piece lever/bar clamp. Evidently even this was not enough to
prevent this failure.


Higher end manufacturers seem to screw up at times. This was my
aluminum
handlebar break which resulted in a nasty crash and bad injuries:

http://www.analogconsultants.com/ng/bike/Handlebar1.jpg

And the design mistake became blatantly obvious:

http://www.analogconsultants.com/ng/bike/Handlebar1.jpg

Should have been that link:

http://www.analogconsultants.com/ng/bike/Handlebar2.jpg
This was from ITM Mondial, not a cheap bar. I replaced it with a
sturdy
MTB steel bar.

That was a pretty odd break. It appears to be made out of the wrong
aluminum alloy.

Liner wasn't in the right place.
Well known defect, see also:
http://www.yellowjersey.org/photosfromthepast/pivo1.jpg
http://www.yellowjersey.org/photosfromthepast/pivo2.jpg

Then again handlebars, just like everything else, can fail
in various ways:
http://www.yellowjersey.org/photosfr...st/failbar.jpg

http://www.yellowjersey.org/photosfr...t/failbar2.jpg

What was the failure mode on that last one? Tangling with a sasquatch?

-- Jay Beattie.


No idea. We started to remove the old tape and found it, with the two
Ergo cables, made a sorta splint holding the shattered bar in place.
I'm curious about how common handlebar breakage is. I know one guy who
broke one maybe 30 years ago. He was a masher riding a time trial bike
with brake cables inside the bar, for aerodynamics. The handlebar
snapped at the cable's exit hole in the bar when he sprinted away from a
standing stop. (Lesson: Don't drill holes in handlebars.)

I have one bar that bent a bit in a crash, and another that I retired
just based on its old age. But I can't think of anyone else I know who
actually broke one.

Anybody here besides Joerg actually break one?

--
- Frank Krygowski

I broke an Easton EC-90 about ten years ago. It started cracked right at the stem clamp. What was frustrating is that I was also using an Em-90 magnesium stem - allegedly recommended bar/stem combination, and yes, I used a torque wrench. I was fortunate that it gave me warning before actually snapping off. I heard a few splintering sounds at one point then noticed the right side seemed 'bent'. Lucky me. I rode directly home with just my left hand..

On 3/9/21 2:28 PM, AMuzi wrote:
On 3/9/2021 3:58 PM, Tom Kunich wrote:
On Tuesday, March 9, 2021 at 1:25:04 PM UTC-8, Joerg wrote:
On 3/9/21 12:47 PM, Joerg wrote:
On 3/8/21 8:43 AM, Tom Kunich wrote:
On Monday, March 8, 2021 at 5:48:04 AM UTC-8, AMuzi wrote:
https://www.bicycleretailer.com/indu...r#.YEYq8BKNWOI


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
Canyon KNEW this was a weak spot and specifically designed a hinged
three piece lever/bar clamp. Evidently even this was not enough to
prevent this failure.


Higher end manufacturers seem to screw up at times. This was my
aluminum
handlebar break which resulted in a nasty crash and bad injuries:

http://www.analogconsultants.com/ng/bike/Handlebar1.jpg

And the design mistake became blatantly obvious:

http://www.analogconsultants.com/ng/bike/Handlebar1.jpg

Should have been that link:

http://www.analogconsultants.com/ng/bike/Handlebar2.jpg
This was from ITM Mondial, not a cheap bar. I replaced it with a sturdy
MTB steel bar.

That was a pretty odd break. It appears to be made out of the wrong
aluminum alloy.


Liner wasn't in the right place.
Well known defect, see also:
http://www.yellowjersey.org/photosfromthepast/pivo1.jpg
http://www.yellowjersey.org/photosfromthepast/pivo2.jpg

Then again handlebars, just like everything else, can fail in various ways:
http://www.yellowjersey.org/photosfr...st/failbar.jpg

http://www.yellowjersey.org/photosfr...t/failbar2.jpg


In my case it was clearly corrosion. They used a cheap non-coated steel
stiffener insert and it started to corrode the aluminum from inside. So
that wasn't visible during inspections when replacing the handlebar
tape. An endoscope would have shown it, if you could get it up there.

--
Regards, Joerg

http://www.analogconsultants.com/

I've never broken a bar, but then I've never fitted a carbon bar or bought one on a bike. Nor an aluminium bar.

Why go looking for trouble to save a few grammes? Be smarter to diet for a day or two.

My bars are made for German and Swiss suppliers in Germany; bars from Kalloy (Uno) in Taiwan have also proven sturdy. Besides them, I trust only the Japanese.

Andre Jute
Common sense alas is not as common as one could wish.

On Wednesday, March 10, 2021 at 10:52:04 AM UTC-8, Andre Jute wrote:
I've never broken a bar, but then I've never fitted a carbon bar or bought one on a bike. Nor an aluminium bar.

Why go looking for trouble to save a few grammes? Be smarter to diet for a day or two.

My bars are made for German and Swiss suppliers in Germany; bars from Kalloy (Uno) in Taiwan have also proven sturdy. Besides them, I trust only the Japanese.

Andre Jute
Common sense alas is not as common as one could wish.
I've never broken a bar but it would be extremely unusual for me to pull on the bar. This is reserved for extremely steep climbs such as the top 100 feet of Mt. Diablo and some F-ing cliff face that my cop friend led me into one time in Novato. There was a flat route and I never suspected that thing was there. It had to be more than 24%. With road bike gearing you sure have a terrible time making up that.

On 3/9/2021 10:41 PM, jbeattie wrote:

Andrew has more data points than me by far, but just listening to my cohorts, bar failures are rare. I did one broken bar case at work, but I represented an innocent bystander who manufactured the bar ends (ControlTech). The uber-light MTB bars that broke were manufactured by a Chinese knock-off company. My expert in that case was the head of products at Easton, and I got a great education in handlebar design -- most of which I've forgotten. The bottom line was that you could make good light bars or just light bars. The Chinese company cut a lot of corners to get the weight down but did little engineering.

Way back when carbon fiber was super-exotic, the first CF bike component
I heard of was being developed by a Materials Engineering student in our
school, a very strong bike racer. That was a straight bar for mountain
biking. I remember how amazed I was at the light weight when he handed
it to me.

Supposedly he was using university fatigue testing equipment to verify
its safety, which would make lots of sense. But I don't know what loads,
etc. he was applying. I wonder if there are industry test standards?

His bar never went into production. I don't know if he couldn't interest
a manufacturer or if he just lost interest after he graduated and got a
real job.


--
- Frank Krygowski

Frank Krygowski writes:

Supposedly he was using university fatigue testing equipment to verify
its safety, which would make lots of sense. But I don't know what
loads, etc. he was applying. I wonder if there are industry test
standards?

There a

https://efbe.de/

They do much tougher test than German norms are requiring. Back in the
alu-oversized days, I bought the cheapest frame listed on their website
that was surviving the torture of 100000 times 1200 N load into the
bottom bracket (simulating a heavy guy pedalling out of the saddle and
pulling like crazy on a the handlebar as for a steep climb).

100000 cycles sound like a lot, but even if you assume a slow cadence of
50/min (probably realistic for this kind of load), you have 3000 cycles
per hour, which amounts to a meagre 33 hours of pedalling out of the
saddle (of course 1200 N is almost ridiculously high).

Back then they had much more information about the test results and test
procedures (most of which is now gone), but the site is still worth some
browsing. I remember a long article about Principia frames: They sent in
half a dozen of prototype frames for testing, all with the same tube
set, but different welding and braze-on details. 5 failed after at most
30000 cycles or so, 1 survived 100000. This was the one then went into
production. There were others, from "famous" but obviously (by request
of the manufacturer) unnamed brands, that failed miserably while
heavier.

Principia, Storck, and Cannondale were the usual suspects on
the lists, each generation of Cannondale's CAAD a 100 g lighter but
still completing the test successfully.

Applied lightweight-engineering. (-:

Axel

On 3/10/2021 1:57 PM, Frank Krygowski wrote:
On 3/9/2021 10:41 PM, jbeattie wrote:

Andrew has more data points than me by far, but just
listening to my cohorts, bar failures are rare. I did one
broken bar case at work, but I represented an innocent
bystander who manufactured the bar ends (ControlTech).
The uber-light MTB bars that broke were manufactured by a
Chinese knock-off company. My expert in that case was the
head of products at Easton, and I got a great education in
handlebar design -- most of which I've forgotten. The
bottom line was that you could make good light bars or
just light bars. The Chinese company cut a lot of corners
to get the weight down but did little engineering.

Way back when carbon fiber was super-exotic, the first CF
bike component I heard of was being developed by a Materials
Engineering student in our school, a very strong bike racer.
That was a straight bar for mountain biking. I remember how
amazed I was at the light weight when he handed it to me.

Supposedly he was using university fatigue testing equipment
to verify its safety, which would make lots of sense. But I
don't know what loads, etc. he was applying. I wonder if
there are industry test standards?

His bar never went into production. I don't know if he
couldn't interest a manufacturer or if he just lost interest
after he graduated and got a real job.



At SR-Sakae, a test handlebar was mounted in a stem on a
bicycle and rolled on a lumpy drum with weights hanging off
the ends. I don't know any numbers but I dis see the setup.

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

On Wednesday, March 10, 2021 at 12:52:17 PM UTC-8, AMuzi wrote:
On 3/10/2021 1:57 PM, Frank Krygowski wrote:
On 3/9/2021 10:41 PM, jbeattie wrote:

Andrew has more data points than me by far, but just
listening to my cohorts, bar failures are rare. I did one
broken bar case at work, but I represented an innocent
bystander who manufactured the bar ends (ControlTech).
The uber-light MTB bars that broke were manufactured by a
Chinese knock-off company. My expert in that case was the
head of products at Easton, and I got a great education in
handlebar design -- most of which I've forgotten. The
bottom line was that you could make good light bars or
just light bars. The Chinese company cut a lot of corners
to get the weight down but did little engineering.

Way back when carbon fiber was super-exotic, the first CF
bike component I heard of was being developed by a Materials
Engineering student in our school, a very strong bike racer.
That was a straight bar for mountain biking. I remember how
amazed I was at the light weight when he handed it to me.

Supposedly he was using university fatigue testing equipment
to verify its safety, which would make lots of sense. But I
don't know what loads, etc. he was applying. I wonder if
there are industry test standards?

His bar never went into production. I don't know if he
couldn't interest a manufacturer or if he just lost interest
after he graduated and got a real job.


At SR-Sakae, a test handlebar was mounted in a stem on a
bicycle and rolled on a lumpy drum with weights hanging off
the ends. I don't know any numbers but I dis see the setup.

The tests I've seen were with hydraulic loading so that they could apply 10 times the loading at 10 times the expected frequency to reach the expected lifespan of the bike in a reasonable period. I can't remember if they only ran it when people were at work or whether it was 24 hours a day with instrumentation to tell them when something broke. This was absolutely far beyond any real life situation and hence it was so well tested that they didn't get any failures except from ad quality control. To tell you how bad counterfeiting is getting the Chinese are making bearings with the Japanese names and packaging on them that only the Japanese can tell from the real thing.. But with 25% of the life.