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-   -   Broken steel road bike fork (http://www.cyclebanter.com/showthread.php?t=209709)

[email protected] September 29th 09 05:37 AM

Broken steel road bike fork
 
So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. I cleaned the wheels last night and rode
into work today. It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1000783.jpg
http://www.bitrealm.com/misc/fork/p1000784.jpg
http://www.bitrealm.com/misc/fork/p1000785.jpg

It was hanging by no more than 2mm of steeel. I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. I don't think it would have held together
and when you lose the front like this, it's going to be bad.

The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. There hasn't been any accident damage since
I put this fork on the bike. The crack was almost all the way
through, starting from the BACK of the fork leg.

Hank September 29th 09 08:23 AM

Broken steel road bike fork
 
On Sep 28, 9:37*pm, wrote:
So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. *The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. *I cleaned the wheels last night and rode
into work today. *It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. *I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. *Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1...k/p1000785.jpg

It was hanging by no more than 2mm of steeel. *I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. *I don't think it would have held together
and when you lose the front like this, it's going to be bad.

The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. *There hasn't been any accident damage since
I put this fork on the bike. *The crack was almost all the way
through, starting from the BACK of the fork leg.


Yikes. Congrats on catching that before disaster struck.

semi-ambivalent[_2_] September 29th 09 01:28 PM

Broken steel road bike fork
 
On Sep 28, 10:37*pm, wrote:
So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. *The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. *I cleaned the wheels last night and rode
into work today. *It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. *I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. *Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1...k/p1000785.jpg

It was hanging by no more than 2mm of steeel. *I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. *I don't think it would have held together
and when you lose the front like this, it's going to be bad.

The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. *There hasn't been any accident damage since
I put this fork on the bike. *The crack was almost all the way
through, starting from the BACK of the fork leg.



You might invest in at least one lottery ticket about now. You know,
before it all wears off.

jim beam[_5_] September 29th 09 01:42 PM

Broken steel road bike fork
 
On 09/28/2009 09:37 PM, wrote:
So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. I cleaned the wheels last night and rode
into work today. It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1000783.jpg
http://www.bitrealm.com/misc/fork/p1000784.jpg
http://www.bitrealm.com/misc/fork/p1000785.jpg

It was hanging by no more than 2mm of steeel. I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. I don't think it would have held together
and when you lose the front like this, it's going to be bad.

The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. There hasn't been any accident damage since
I put this fork on the bike. The crack was almost all the way
through, starting from the BACK of the fork leg.


chrome plate is bad for fatigue - it contains many fatigue initiators.

for the future, consider quality cfrp - unless abused, it's pretty much
"fatigue proof".

M-gineering September 29th 09 01:43 PM

Broken steel road bike fork
 
wrote: The crack was almost all the way
through, starting from the BACK of the fork leg.


No surprise here, if they break, that's where they go
--
/Marten

info(apestaartje)m-gineering(punt)nl

raamman September 29th 09 02:52 PM

Broken steel road bike fork
 
On Sep 29, 12:37*am, wrote:
So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. *The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. *I cleaned the wheels last night and rode
into work today. *It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. *I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. *Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1...k/p1000785.jpg

It was hanging by no more than 2mm of steeel. *I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. *I don't think it would have held together
and when you lose the front like this, it's going to be bad.

The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. *There hasn't been any accident damage since
I put this fork on the bike. *The crack was almost all the way
through, starting from the BACK of the fork leg.


well, there you go, "steel is real" has been the mantra- but the
phrase " suseptable to rust" could be added. The fork looks very
clean, so I wonder how it happened to escape your notice earlier. I am
glad you escaped any mishap.

Peter Cole[_2_] September 29th 09 03:04 PM

Broken steel road bike fork
 
wrote:
So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. I cleaned the wheels last night and rode
into work today. It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1000783.jpg
http://www.bitrealm.com/misc/fork/p1000784.jpg
http://www.bitrealm.com/misc/fork/p1000785.jpg

It was hanging by no more than 2mm of steeel. I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. I don't think it would have held together
and when you lose the front like this, it's going to be bad.

The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. There hasn't been any accident damage since
I put this fork on the bike. The crack was almost all the way
through, starting from the BACK of the fork leg.


If lugs aren't designed right they concentrate stress at the edges and
that's where they fatigue.

[email protected] September 29th 09 03:21 PM

Broken steel road bike fork
 
On Sep 29, 5:42*am, jim beam wrote:
On 09/28/2009 09:37 PM, wrote:



So, I've been noticing that the front brakes of my road bike
were acting "grabby" in that the front would shimmy pretty
badly just as I'm coming to a stop. *The rims felt a little
sticky, maybe some Gatorade got on them and it hasn't really
rained in a while. *I cleaned the wheels last night and rode
into work today. *It was still bad, but didn't seem as bad.
This has been going on for a week, I didn't think anything of
it. *I decided to not ride after work and just come home, coming
down the driveway, the grabby-ness was really pronounced, so
I figure that the brake pads must be contaminated with something.
When I took the wheel off, my heart skipped a beat. *Without much
effort, this is the result:


http://www.bitrealm.com/misc/fork/p1000783.jpg
http://www.bitrealm.com/misc/fork/p1000784.jpg
http://www.bitrealm.com/misc/fork/p1000785.jpg


It was hanging by no more than 2mm of steeel. *I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. *I don't think it would have held together
and when you lose the front like this, it's going to be bad.


The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. *There hasn't been any accident damage since
I put this fork on the bike. *The crack was almost all the way
through, starting from the BACK of the fork leg.


chrome plate is bad for fatigue - it contains many fatigue initiators.

for the future, consider quality cfrp - unless abused, it's pretty much
"fatigue proof".


This fork was on the bike for about 8 years and had probably around
12K miles on it in that time.

I would like to find a 1" threaded replacement that has eyelets for
fenders,
but they seem pretty thin on the ground. I can find the exact same
fork
shown here (in black) that I could still buy. It was a 200 mm steerer
tube with 35mm of threading. Cut, it is 190mm with 25mm of threading.
The one shown here was made for 27" wheels and I just run long reach
calipers. I had to have the crown race cut from 27 to 26.4mm.

If not, any 1" threadless forks with eyelets and room for fenders?

Anyone, Bueller?

Tim McNamara September 29th 09 04:29 PM

Broken steel road bike fork
 
In article
,
wrote:

On Sep 29, 5:42*am, jim beam wrote:
On 09/28/2009 09:37 PM, wrote:

So, I've been noticing that the front brakes of my road bike were
acting "grabby" in that the front would shimmy pretty badly just
as I'm coming to a stop. *The rims felt a little sticky, maybe
some Gatorade got on them and it hasn't really rained in a while.
*I cleaned the wheels last night and rode into work today. *It
was still bad, but didn't seem as bad. This has been going on for
a week, I didn't think anything of it. *I decided to not ride
after work and just come home, coming down the driveway, the
grabby-ness was really pronounced, so I figure that the brake
pads must be contaminated with something. When I took the wheel
off, my heart skipped a beat. *Without much effort, this is the
result:


http://www.bitrealm.com/misc/fork/p1000783.jpg
http://www.bitrealm.com/misc/fork/p1000784.jpg
http://www.bitrealm.com/misc/fork/p1000785.jpg


It was hanging by no more than 2mm of steeel. *I shudder when I
think of the roads I was about to go on, including one really bad
bump at the bottom. *I don't think it would have held together
and when you lose the front like this, it's going to be bad.


The shimmy was the wheel moving back and forth due to the fork
leg being fatigued. *There hasn't been any accident damage since
I put this fork on the bike. *The crack was almost all the way
through, starting from the BACK of the fork leg.


The crack initiating in the back of the leg is not unusual.

chrome plate is bad for fatigue - it contains many fatigue
initiators.


Chrome plating *can* result in embrittlement but does not necessarily do
so. Millions of bikes and other load bearing appplications are chromed
without such failures happening.

The reason for the failure seem pretty self-evident in the photo. Note
how the crack followed the shore line of the socket so perfectly, and
note the relative thicknesses of the metal. Note also the lack on a
reinforcement tang on the inside of the fork leg.

for the future, consider quality cfrp - unless abused, it's pretty
much "fatigue proof".


More clueless advice from "jim beam."

This fork was on the bike for about 8 years and had probably around
12K miles on it in that time.

I would like to find a 1" threaded replacement that has eyelets for
fenders, but they seem pretty thin on the ground. I can find the
exact same fork shown here (in black) that I could still buy. It was
a 200 mm steerer tube with 35mm of threading. Cut, it is 190mm with
25mm of threading. The one shown here was made for 27" wheels and I
just run long reach calipers. I had to have the crown race cut from
27 to 26.4mm.

If not, any 1" threadless forks with eyelets and room for fenders?


Harder to find these days since most aftermarket forks are aluminum or
CF, lack eyelets and are for 700C wheels (if the bike was made for 27"
wheels, going to a 700C fork will affect the geometry). But I would
think that any bike shop with a QBP account could order you a fork to
fit. Or you could have one made, but that would be expensive.

Frank Krygowski[_2_] September 29th 09 08:50 PM

Broken steel road bike fork
 
On Sep 29, 12:37*am, wrote:
...
When I took the wheel off, my heart skipped a beat. *Without much
effort, this is the result:

http://www.bitrealm.com/misc/fork/p1...k/p1000785.jpg

It was hanging by no more than 2mm of steeel. *I shudder when I
think of the roads I was about to go on, including one really
bad bump at the bottom. *I don't think it would have held together
and when you lose the front like this, it's going to be bad.


Lucky you caught it when you did. Last year, our old custom tandem
let go of both blades simultaneously. The warnings I got were nowhere
near as explicit as yours. Fortunately, we were moving only about 10
mph at the time.

In my case, the bike was built by Jim Bradford, formerly of the
Atlanta, Georgia area. It was the last bike he built before getting
married and leaving on a honeymoon. I suspect he slapped in whatever
fork blades he had lying around in order to get the job done, because
the wall thickness was roughly one-third of the proper gage for
Reynolds 531 tandem forks.

I wish I could offer advice on how to choose a competent and ethical
frame builder, but I can't.

BTW, I think you shouldn't have too much trouble finding a
replacement. I was able to buy a replacement tandem fork from Tandems
Ltd in Alabama. For a single bike I intend to build, just last year I
was able to buy a chromed Japanese fork from Citybikes in Portland,
Oregon. http://www.citybikes.coop/

- Frank Krygowski


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