Re: The probability of frame cracking?

jtaylor said:

The Trek 470 is an aluminium-framed bicycle (if my reading is correct).

No, the 1996 model was steel (and steel will crack too - my Dad crashed
in the Isle of Man TT when the forks of his sidecar outfit broke due to
a cracked weld - although an F2 racing sidecar goes through A LOT more
punishment than a bicycle - his steel sidecar frames have to have cracks
repaired pretty frequently).

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

jtaylor said:

Dylan Smith said:

Ten years ago, I bought a new road bike. Since then, I've moved from
Houston where I bought it to the Isle of Man. The route I like doing
goes from my house, up about 1000' of hill, and eventually back down the
other side.

It's normal tarmac road, but surfaced in that rather coarse road
surface. The road itself ..erm.. 'undulates'. On the downhill sections I
start going very fast. The typical quality of the road surface is such
that I always marvel at how smooth the roads are in England whenever I
take the car across. Already, I've removed the aerobars because they
kept rattling loose (and I really don't use them any more - on the Texas
Gulf coast it's as flat as a billiard table so I used them lots, but
going up and down hills I've found little call for them). My tyres are
inflated to 120psi. Although the road surface does cause vibration it's
not horrible - I've not yet had a puncture in 4 years of riding here (I
used to get punctures all the time in Houston) and since removing the
aerobars, the bike itself doesn't rattle anywhere (well apart from a
slight noise from the chain area when I'm not pedaling, I assume when
not under tension from applying power it can vibrate a bit).

However, I have nightmares about frame cracks from the roughness. The
bike is a Trek 470 (about $600 worth when new in 1996). In particular, I
have nightmares about the front forks letting go when coming down the
hill. Am I just being paranoid? Any places that bike frames tend to
crack most often?

The Trek 470 is an aluminium-framed bicycle (if my reading is correct).
When it fails (not if) the failure is likely to be sudden.

Where and how do you internet bicyclists come up with this stuff?

Checking

Quoted message said:

regularly for cracks may allow you to forestall this, but you could still
miss the one that matters.

A steel frame may suit your psyche and rough roads better.

in message <[email hidden]!nnrp1.uunet.ca>, jtaylor

(') said:

Quoted message said:

However, I have nightmares about frame cracks from the roughness. The
bike is a Trek 470 (about $600 worth when new in 1996). In particular,
I have nightmares about the front forks letting go when coming down
the hill. Am I just being paranoid? Any places that bike frames tend
to crack most often?

The Trek 470 is an aluminium-framed bicycle (if my reading is correct).
When it fails (not if) the failure is likely to be sudden. Checking
regularly for cracks may allow you to forestall this, but you could
still miss the one that matters.

Have you, honestly, ever seen a cracked aluminium frame? I have, actually
- one. As against at least a dozen cracked steel ones. The cracked
aluminium frame successfully completed a cross country mountain bike
race, despite the non-drive-side chain-stay being cracked through just
behind the suspension pivot.

Quoted message said:

A steel frame may suit your psyche and rough roads better.

But is at least as likely to crack.

Just a reminder: in the only actual published comparative test (that I'm
aware of) that's been done on this, the steel frames cracked and failed,
the aluminium ones didn't. Now, I recognise there's been a fair bit of
criticism of the test regime in that test, but no-one has come up with a
better test regime and then carried out their own test. So the current
score is Aluminium 1, Steel nil.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; If Python is executable pseudocode,
;; then Perl is executable line noise
-- seen on Slashdot.

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

Quoted message said:

in message <[email hidden]!nnrp1.uunet.ca>, jtaylor

(') said:

Quoted message said:

However, I have nightmares about frame cracks from the roughness. The
bike is a Trek 470 (about $600 worth when new in 1996). In particular,
I have nightmares about the front forks letting go when coming down
the hill. Am I just being paranoid? Any places that bike frames tend
to crack most often?

The Trek 470 is an aluminium-framed bicycle (if my reading is correct).
When it fails (not if) the failure is likely to be sudden. Checking
regularly for cracks may allow you to forestall this, but you could
still miss the one that matters.

Have you, honestly, ever seen a cracked aluminium frame? I have, actually
- one. As against at least a dozen cracked steel ones. The cracked
aluminium frame successfully completed a cross country mountain bike
race, despite the non-drive-side chain-stay being cracked through just
behind the suspension pivot.

Quoted message said:

A steel frame may suit your psyche and rough roads better.

But is at least as likely to crack.

That's not the issue.

The issue is the nature of failure.

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

Simon Brooke said:

in message <[email hidden]!nnrp1.uunet.ca>, jtaylor

(') said:

Quoted message said:

However, I have nightmares about frame cracks from the roughness. The
bike is a Trek 470 (about $600 worth when new in 1996). In particular,
I have nightmares about the front forks letting go when coming down
the hill. Am I just being paranoid? Any places that bike frames tend
to crack most often?

The Trek 470 is an aluminium-framed bicycle (if my reading is correct).
When it fails (not if) the failure is likely to be sudden. Checking
regularly for cracks may allow you to forestall this, but you could
still miss the one that matters.

Have you, honestly, ever seen a cracked aluminium frame? I have, actually
- one. As against at least a dozen cracked steel ones. The cracked
aluminium frame successfully completed a cross country mountain bike
race, despite the non-drive-side chain-stay being cracked through just
behind the suspension pivot.

Add mine to the count. My aluminum Trek Fuel-80 developed a crack in the
top tube right in front of the seatpost last summer. Fortunately it was
covered and after nine long weeks Trek sent a carbon-fiber frame to
replace it. Of course I still had to pay for dis-assembly and
re-assembly, something they don't tell you when they're advertising the
lifetime warranty. Don't ask, don't tell, I guess. Still, I have a
carbon-fiber frame now, and it creaks no worse than the aluminum one did.

jtaylor said:

"Simon Brooke" <[email hidden]> wrote in message

Quoted message said:

Quoted message said:

Have you, honestly, ever seen a cracked aluminium frame? I have, actually
- one. As against at least a dozen cracked steel ones. The cracked
aluminium frame successfully completed a cross country mountain bike
race, despite the non-drive-side chain-stay being cracked through just
behind the suspension pivot.

Quoted message said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

That hasn't been my experience. I've had two cracks in steel bicycles
and neither one gave significant warning. One was pretty harmless
since it was in a rear stay and the only result was that the tire
pulled over and rubbed against the frame. However, the other one was a
crack and complete separation of the steerer tube resulting in loss of
the front wheel & fork while I was riding. It caused an immediate
crash and considerable injury.

Both bikes were repaired and are still in use, but my main bike now is
an aluminum-framed one that is approaching the 100k mile mark with no
problems to date.

in message <[email hidden]!nnrp1.uunet.ca>, jtaylor

(') said:

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

Quoted message said:

in message <[email hidden]!nnrp1.uunet.ca>,

jtaylor (') said:

> However, I have nightmares about frame cracks from the roughness.
> The bike is a Trek 470 (about $600 worth when new in 1996). In
> particular, I have nightmares about the front forks letting go when
> coming down the hill. Am I just being paranoid? Any places that
> bike frames tend to crack most often?

The Trek 470 is an aluminium-framed bicycle (if my reading is
correct).
When it fails (not if) the failure is likely to be sudden. Checking
regularly for cracks may allow you to forestall this, but you could
still miss the one that matters.

Have you, honestly, ever seen a cracked aluminium frame? I have,
actually - one. As against at least a dozen cracked steel ones. The
cracked aluminium frame successfully completed a cross country
mountain bike race, despite the non-drive-side chain-stay being
cracked through just behind the suspension pivot.

Quoted message said:

A steel frame may suit your psyche and rough roads better.

But is at least as likely to crack.

That's not the issue.

The issue is the nature of failure.

Steel frames give warning - the cracks usually grow slowly enough that
the
rider gets off and looks to see why his bike feels rubbery. The rider
of an aluminium-framed bicycle that cracks can find himself getting off
for quite another reason.

I say again: have you, personally, any direct experience of this? As I
have said, the /only/ aluminium bike I have known to have cracked
remained not merely rideable but raceable after the crack. Can you
actually point to any documented incident - anywhere, ever - of an
aluminium frame just letting go suddenly, or are you merely recycling
disinformation and old wives' tales?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I can't work yanks out......
;; Why do they frown upon sex yet relish violence?
;; Deep Fried Lettuce

jtaylor said:

"Simon Brooke" <[email hidden]> wrote in message

<snip>

Quoted message said:

Quoted message said:

Quoted message said:

A steel frame may suit your psyche and rough roads better.

But is at least as likely to crack.

That's not the issue.

The issue is the nature of failure.

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

I broke a couple of Al frames, and neither failed catestrophically.
One did not fail at all, since I found the crack while doing my
semi-annual clean-a-thon. The other bike/frame started squirming in a
climb, and I stopped to find that the down tube was cracked through
about half of its circumference. These were relatively old school
Cannondale frames, but probably pretty characteristic of today's low
and mid-priced aluminum frames. I know nothing about the failure mode
of the uber-lite Al frames -- or the uber-lite steel frames for that
matter. I would like to know whether the modern light weight steel
tubes retain all those characteristics which we so fondly attribute to
531, SL, SP, etc. like slow crack propagation and fixability. -- Jay
Beattie.

Simon Brooke said:

So the current score is Aluminium 1, Steel nil.

Only frame I've had that cracked was aluminium. The chainstay went at the
bridge. It took about a week from noticing a strange clicking sound when sat
in the saddle, to finding the tube had sheared right through on its Sunday
clean up.

But this is all just anecdote.

Quoted message said:

Quoted message said:

So the current score is Aluminium 1, Steel nil.

Ti 1. The drive side chainstay on my Lemond cracked all
the way through at the BB shell last weekend. It was
still ridable if you were very, very careful.

Most frame failures aren't catastrophic in a way that dumps
you onto the pavement. So far I've had (in steel) a BB shell
crack, two head tube/lugs crack, and a downtube crack
at the water bottle boss. In Ti the chainstay has cracked.
All were still sort of rideable, though the handling could be
snakey. The classic frame layout has quite a bit of redundancy
for tube failure.

The big danger is a fork or handlebar/stem failure. I had
an Al fork steerer tube snap. Luckily that was at low
speed and I managed to get it stopped without a
crash. It was a walk and a taxi ride home, though.

Quoted message said:

Ti 1. The drive side chainstay on my Lemond cracked all
the way through at the BB shell last weekend.

BTW, does anyone know when the new Lemond carbon fiber
bikes will actually hit the stores? If, as expected, I get a warranty
credit on this I might just buy a new carbon fiber bike, seeing
as how they don't make the Ti frame any more.

jtaylor said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

A friend of mine had a steel MTB frame fail suddenly with a sheared top
and down tube while dropping off a ledge at Moab at speed. You can
imagine the result. The frame was from a builder well known for pushing
the limits of steel.

Here's another example of a steel frame failing with no warning:
http://www.fischer-wade.net/steelisreal.htm

My personal experience is three broken steel frames and no broken
aluminum frames even though I've been racing road, cross and MTB on
Easton aluminum for the last six years.

Bret

In article
<[email hidden]>,

Quoted message said:

jtaylor said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

A friend of mine had a steel MTB frame fail suddenly with a sheared top
and down tube while dropping off a ledge at Moab at speed. You can
imagine the result. The frame was from a builder well known for pushing
the limits of steel.

Here's another example of a steel frame failing with no warning:
http://www.fischer-wade.net/steelisreal.htm

I vigorously contest the assertion that it failed without
warning.

The widespread corrosion is a dire warning.

There are cracks/tears on the down tube-head tube lug that
are dire warnings. These cracks and tears show corrosion
that would have been easily visible before the failure.

The amount of corrosion and cracks would have made the
handling of the bicycle very loose. This is a dire
warning.

I have seldom seen a JRA account so utterly without merit.
Case dismissed. Plaintiff to pay costs.

Quoted message said:

My personal experience is three broken steel frames and no broken
aluminum frames even though I've been racing road, cross and MTB on
Easton aluminum for the last six years.

Bret

--
Michael Press

Quoted message said:

jtaylor said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

A friend of mine had a steel MTB frame fail suddenly with a sheared top
and down tube while dropping off a ledge at Moab at speed. You can
imagine the result. The frame was from a builder well known for pushing
the limits of steel.

Here's another example of a steel frame failing with no warning:
http://www.fischer-wade.net/steelisreal.htm

My personal experience is three broken steel frames and no broken
aluminum frames even though I've been racing road, cross and MTB on
Easton aluminum for the last six years.

The way the lugs are peeled away from the tube, and
top tube miter is visible - that is the top tube doesn't
look broken, but separated from the head tube - suggest
bad joints to me.

I don't have much experience with frame failures (cross
fingers) but it seems likely to me that most frame failures
start with a crack somewhere, and unless they get suddenly
worse due to an impact, the frame failure is generally not
catastrophic. This can happen with both steel and
aluminum (I think jtaylor is wrong there).
Breaking a chainstay or cracking the downtube doesn't
have to mean faceplant, unless you are dropping
off a ledge.

However, _fork_ failures do generally mean the rider gets
off the hard way. This is why, I think, forks usually have a
bigger safety margin than frames.

jtaylor said:

The Trek 470 is an aluminium-framed bicycle (if my reading is correct).
When it fails (not if) the failure is likely to be sudden.

No, it won't. Cracks will be obvious -- by the noise if nothing else --
well before it completely comes from together. I found the crack in my
aluminum frame by trying to chase down an annoying sound.

You (OP) seem to be getting your $600 worth from this bike. Ride it, and
enjoy it, unless and until it dies, then get another bike. Maybe not
aluminum, but that is up to you.

--

David L. Johnson

__o | It is a scientifically proven fact that a mid life crisis can
_`\(,_ | only be cured by something racy and Italian. Bianchis and
(_)/ (_) | Colnagos are a lot cheaper than Maserattis and Ferraris. --
Glenn Davies

Ernst Blofeld said:

I had
an Al fork steerer tube snap. Luckily that was at low
speed and I managed to get it stopped without a
crash. It was a walk and a taxi ride home, though.

Where did the tube break? Top or bottom, or somewhere else? Thanks!

Michael Press said:

In article
<[email hidden]>,

Quoted message said:

jtaylor said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

A friend of mine had a steel MTB frame fail suddenly with a sheared top
and down tube while dropping off a ledge at Moab at speed. You can
imagine the result. The frame was from a builder well known for pushing
the limits of steel.

Here's another example of a steel frame failing with no warning:
http://www.fischer-wade.net/steelisreal.htm

I vigorously contest the assertion that it failed without
warning.

The widespread corrosion is a dire warning.

There are cracks/tears on the down tube-head tube lug that
are dire warnings. These cracks and tears show corrosion
that would have been easily visible before the failure.

The amount of corrosion and cracks would have made the
handling of the bicycle very loose. This is a dire
warning.

I have seldom seen a JRA account so utterly without merit.
Case dismissed. Plaintiff to pay costs.

The frame failed over ten years ago. The corrosion came later. The
picture is recent. Since both the top and down tubes seperated from the
lugs, I've alway assumed that it failed because of very poor braising.
This is not typical of steel frames, but it's possible as this frame
shows.

Bret

Quoted message said:

Quoted message said:

jtaylor said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

A friend of mine had a steel MTB frame fail suddenly with a sheared top
and down tube while dropping off a ledge at Moab at speed. You can
imagine the result. The frame was from a builder well known for pushing
the limits of steel.

Here's another example of a steel frame failing with no warning:
http://www.fischer-wade.net/steelisreal.htm

My personal experience is three broken steel frames and no broken
aluminum frames even though I've been racing road, cross and MTB on
Easton aluminum for the last six years.

The way the lugs are peeled away from the tube, and
top tube miter is visible - that is the top tube doesn't
look broken, but separated from the head tube - suggest
bad joints to me.

Me, too. Both joints look really dry -- although the lower lug looks
ripped up, like the bike had a big wall impact. There is a lot of
corrosion, too, which may or may not have been apparent before the
crash. In any event, all that corrosion adds fuel to the arguments
made by the non-ferrous folks.

Quoted message said:

However, _fork_ failures do generally mean the rider gets
off the hard way. This is why, I think, forks usually have a
bigger safety margin than frames.

IME, most JRA fork failires result from improper joinery. CF that is
not glued propery, poor brazing/wedling on steel or aluminum. I had a
friend who bought a one-off tandem made by a very well known builder,
and the fork blades were tacked in but never finished-off. They fell
apart on a big downhill in the Bay Area. Major carnage for my friend
and his girlfriend. -- Jay Beattie..

Quoted message said:

jtaylor said:

Steel frames give warning - the cracks usually grow slowly enough that the
rider gets off and looks to see why his bike feels rubbery. The rider of an
aluminium-framed bicycle that cracks can find himself getting off for quite
another reason.

A friend of mine had a steel MTB frame fail suddenly with a sheared top
and down tube while dropping off a ledge at Moab at speed. You can
imagine the result. The frame was from a builder well known for pushing
the limits of steel.

Here's another example of a steel frame failing with no warning:
http://www.fischer-wade.net/steelisreal.htm

My personal experience is three broken steel frames and no broken
aluminum frames even though I've been racing road, cross and MTB on
Easton aluminum for the last six years.

The only steel frame I've broken was a 1986 Bridgestone MB-1. It was a
common failure with the downtube breaking close to the headtube lug.
The break was sudden and without warning, and thankfully riding gingerly
the top tube held up on the 7.5 mile ride back to the truck. It had
failed on a 15 mile winter out-and-back night ride right at the
turnaround point.

Other than that I've owned 6 steel mtn bike frames, one of which I still
have (a 13 year old Bontrager), broken all 3 aluminum hardtails and the
one carbon fiber hardtail I've owned. I don't keep my aluminum full
suspension bikes long enough to see when they're going to break.

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons