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Old 11-19-11, 02:35 PM   #1
clawhammer72
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How bad is this crack?

I've had this bike for about 15 years. The crack has been there for a long time, but I just started commuting regularly, and now after 3 months and 400 miles, the crack seems to be getting bigger.

It's an aluminum frame. I know I will have to get a new bike/frame at some point, but I am wondering how soon that has to be.

Is it likely or unlikely for this type of crack to fail catastrophically or will it just get slowly worse and worse? I know that know one can guarantee an answer one way or the other, and I know it's ultimately my risk, but I am interested in some experienced opinions taken just as that -- opinions.

Thanks in advance!


Last edited by clawhammer72; 11-19-11 at 02:47 PM. Reason: Add photo
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Old 11-19-11, 02:39 PM   #2
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can't see you picture, but if the crack is increasing in size, would consider the frame in need of immediate scrapping, and replacement. For failure, Aluminum does like to fail with no warning.
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Old 11-19-11, 02:41 PM   #3
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Sorry. I'm working on the picture.
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Old 11-19-11, 02:50 PM   #4
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Imminent fail! One good drop of a curb, into a pothole and you are likely to have an infinitely extended wheelbase.
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Old 11-19-11, 02:59 PM   #5
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If the crack is showing signs of propagation, stop riding it immediately. It can and one day will spread all the way though the headtube and when that happens you'd better have a good dental plan. Once the structural integrity of aluminum is compromised, it can fail rapidly.
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Old 11-19-11, 03:00 PM   #6
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Yep, it's FUBAR
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Old 11-19-11, 03:01 PM   #7
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Searching through the threads, I found this from Sheldon Brown. (Sorry, I couldn't figure out how to link to the thread as a quote.)

Begin Quote**********
"If you're going to keep riding it, it would be a good idea to drill a small (3/16"?) hole just where the crack ends. This will stop the sharp end of the crack from acting as a stress riser. If you don't do that, the crack is liable to grow.

The poster who wrote "This crack could result in a sudden failure." is a well-meaning alarmist. The location of the crack means that it is mainly stressed in static weight bearing. It carries no share of braking load.

If the problem does get worse (the crack grows) it will give you plenty of warning. It will feel as if the headset is misadjusted (too loose) LOOOOOOONG before there's any chance of "sudden failure."

Sheldon "Seen This Before" Brown"
End Quote*********

Given that I've been riding this bike for years with the crack, I'm just not ready to throw in the towel unless I can get a little more evidence about why this crack is a big problem. I appreciate opinions, but I would like to know the reasons behind the opinion, at least so that I can make an informed decision.

Of course, I'm not interested in risking life and limb just to save a few hundred bucks.

Last edited by clawhammer72; 11-19-11 at 03:03 PM. Reason: clarify quotation
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Old 11-19-11, 03:13 PM   #8
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Originally Posted by clawhammer72 View Post
Searching through the threads, I found this from Sheldon Brown. (Sorry, I couldn't figure out how to link to the thread as a quote.)

Begin Quote**********
"If you're going to keep riding it, it would be a good idea to drill a small (3/16"?) hole just where the crack ends. This will stop the sharp end of the crack from acting as a stress riser. If you don't do that, the crack is liable to grow.

The poster who wrote "This crack could result in a sudden failure." is a well-meaning alarmist. The location of the crack means that it is mainly stressed in static weight bearing. It carries no share of braking load.

If the problem does get worse (the crack grows) it will give you plenty of warning. It will feel as if the headset is misadjusted (too loose) LOOOOOOONG before there's any chance of "sudden failure."

Sheldon "Seen This Before" Brown"
End Quote*********

Given that I've been riding this bike for years with the crack, I'm just not ready to throw in the towel unless I can get a little more evidence about why this crack is a big problem. I appreciate opinions, but I would like to know the reasons behind the opinion, at least so that I can make an informed decision.

Of course, I'm not interested in risking life and limb just to save a few hundred bucks.
That crack is big enough that I would look at replacing it, even though I don't think "sudden failure" is a high probability.
The drill a hole at the edge of a crack to stop propagation is a common practice to stop cracks from spreading,
but I wouldn't do it here, it would just be a stop gap measure, until you replace the frame.
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Old 11-19-11, 03:17 PM   #9
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From the location of the crack, it was probably caused by a bad install of the lower headset cup, as others, would consider that crack is propagating; i.e. it's getting bigger, and it will fail.

Your choice to continue to ride, but most other people would consider their health & safety as a high priority, and the risk of that reducing the quality of their health is greater than the cost saving of not fixing it.
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Old 11-19-11, 03:23 PM   #10
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two words: hose clamp
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Old 11-19-11, 03:31 PM   #11
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Worst case scenario; An "over the bars" accident. Yup, I'd dump it. bk
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Old 11-19-11, 03:39 PM   #12
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two words: hose clamp
the best it would do is stop the steerer from punching through entirely.


from the looks of it, the crack is over 1" long and branching, so drilling stop holes wouldn't really help much, because it's already above the bottom of the weld on the opposite side.
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Old 11-19-11, 03:41 PM   #13
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Originally Posted by bhchdh View Post
two words: hose clamp
+1

If there's room below the downtube weld, a hose clamp will short it up very nicely. Otherwise, it there's some extension of the tube below the weld, but not enough for a hose clamp, you can save it with thin stainless steel wire as follows.

1-Remove the lower cup, and wind multiple turns of wire around the lower section tightly pulling the crack closed. use as many turns as will fit nicely, but don't go more than two layers deep because it'll come off the end.

2-Tie off by trapping the end under the last turn and pulling tight.

3-coat the job with JB Weld, Plastic Aluminum, or epoxy to protect the wire and keep everything in place. What you use here isn't critical since the strength comes from the wire, just cover it all nicely, without going over the lower lip of the tube. Also coat the crack above the wire to close it up.

4-wait 48 hours for the resin to cure then press in the lower cup, install the fork, adjust everything and you're good to go.

5- if you want to be a bit fancier, you can add a small patch of Stainless screen mesh over the exposed crack, and hold that in place with the same epoxy.

Odds are this repair, if done carefully, will outlast the rest of the bike.

You should attend to this ASAP before the crack extends to the point that a repair will be more difficult if not impossible "a stitch in time....."

If you do nothing, the crack isn't likely to lead to a sudden catastrophic failure without plenty of warning is the form of a loose noisy headset. Keep an eye on it especially for the start of a second crack or branch which might cause a chunk of tube to come off at the bottom. The worst likely consequences of riding it as is are crack propagation to the point of unrepairability, permanent loose headset reducing control, especially during braking, or an on road failure causing a long walk home.



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Last edited by FBinNY; 11-19-11 at 04:45 PM.
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Old 11-19-11, 03:41 PM   #14
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Quote:
Originally Posted by clawhammer72 View Post
Searching through the threads, I found this from Sheldon Brown. (Sorry, I couldn't figure out how to link to the thread as a quote.)

Begin Quote**********
"If you're going to keep riding it, it would be a good idea to drill a small (3/16"?) hole just where the crack ends. This will stop the sharp end of the crack from acting as a stress riser. If you don't do that, the crack is liable to grow.

The poster who wrote "This crack could result in a sudden failure." is a well-meaning alarmist. The location of the crack means that it is mainly stressed in static weight bearing. It carries no share of braking load.

If the problem does get worse (the crack grows) it will give you plenty of warning. It will feel as if the headset is misadjusted (too loose) LOOOOOOONG before there's any chance of "sudden failure."

Sheldon "Seen This Before" Brown"
End Quote*********

Given that I've been riding this bike for years with the crack, I'm just not ready to throw in the towel unless I can get a little more evidence about why this crack is a big problem. I appreciate opinions, but I would like to know the reasons behind the opinion, at least so that I can make an informed decision.

Of course, I'm not interested in risking life and limb just to save a few hundred bucks.
Sounds like you've made up your mind. Let us know the details when it finally goes, would you please?
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Old 11-19-11, 03:54 PM   #15
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Thats growing into a significant crack...looks to be 1/4 or a 1/3 of the length of the headtube. I've seen plenty of much smaller cracks warrantied...Speaking of, did you think about trying to get it warrantied?

My opinion is that its time to move onto a new frame. The reason is that headtubes are not designed to properly support a rider's weight with a crack through the middle of it. I can't say I've ever seen first hand a cracked headtube fail catastrophically. But a cracked headtube is certainly more likely to fail than a non-cracked headtube. Not sure about you commute, but if it encounters potholes, cars, descents, etc. you're increasing the chance of failure and potentially significant consequences. Its really just a personal risk analysis.

Nashbar is selling frames at like $60 all the time.
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Old 11-19-11, 04:01 PM   #16
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Imminent fail! One good drop of a curb, into a pothole and you are likely to have an infinitely extended wheelbase.
Not to mention an involuntary 'facelift'
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Old 11-19-11, 04:04 PM   #17
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There are three possibly ways this can unfold:

1. You choose to not ride the bike again. A shiny new (or used) bike will catch your eye the moment you step in the door. You will try to stay detached but the bike will be calling your name in a song of quick glints reflecting from the overhead lights and the flirtatious way the price tag is waving in the breeze from the room ventilation system. You will buy the bike. Some day in the future you will tell your grandchildren about the day you bought the new bike, and what a great bike it's been, and about all the great adventures you have had with the bike.

2. You continue to ride the bike. You will notice a gradual increase in headset play over the next few five or 50 miles, and one day you will realize it is getting a pretty loose and increasingly difficult to ride. You will be ridding uncomfortably past a bike store and decide, 'hey, what the hell - I'll take a breather and have a look inside. A shiny new (or used) bike will catch your eye the moment you step in the door. You will try to stay detached but the bike will be calling your name in a song of quick glints reflecting from the overhead lights and the flirtatious way the price tag is waving in the breeze from the room ventilation system. You will buy the bike and when you ask the staff of the store how you can get rid of your old bike, and show it to them, you will get stares of incredulity as if they are talking to a dead body, or perhaps someone who was almost just now nearly been killed. Some day in the future you will tell your grandchildren about the day you bought the new bike, and what a great bike it's been, and about all the great adventures you have had with the bike.

3. You continue to ride the bike. You start out for work one day and when you turn out of your driveway the front half of your bike breaks off. You fall to the ground too suddenly to react and you land face-first on the curb. You are now brain damaged, or a paraplegic, or dead.

Until you stop riding the bike, at any time with no warning whatsoever, #2 can become #3.

Last edited by LarDasse74; 11-19-11 at 04:08 PM.
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Old 11-19-11, 05:42 PM   #18
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Thanks for the input. It's a bummer to say goodbye to this bike, but it will be fun looking for a replacement. Looks like a steel frame is coming my way. : )
In the meantime, I'll just stick to my recumbent.
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Old 11-19-11, 06:03 PM   #19
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Faceplant that just hasn't happened yet.

I'd chuck it but cut it up first so someone else doesn't try to use it and kill themselves.
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Old 11-19-11, 07:26 PM   #20
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I'm convinced. And better yet, my wife is in full agreement. New bike here we come. Thanks again.
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Old 11-19-11, 07:59 PM   #21
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Yeah, although it looks like there's still plenty of metal holding your fork in, aluminium can let go in a big hurry sometimes, and if a decent chunk were to break off, there's a chance it could be quite nasty.

You could almost certainly get away with FB's approach, which some people would find very satisfying. But as much as I like rescuing stuff other folks call trashed, I'd junk it.
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Old 11-19-11, 09:27 PM   #22
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1st time i see a crack that big.
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Old 11-19-11, 11:04 PM   #23
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I've had this bike for about 15 years. The crack has been there for a long time, but I just started commuting regularly, and now after 3 months and 400 miles, the crack seems to be getting bigger.

It's an aluminum frame. I know I will have to get a new bike/frame at some point, but I am wondering how soon that has to be.

Is it likely or unlikely for this type of crack to fail catastrophically or will it just get slowly worse and worse? I know that know one can guarantee an answer one way or the other, and I know it's ultimately my risk, but I am interested in some experienced opinions taken just as that -- opinions.
Does the steering feel loose? You Socal guys have such smooth roads. That wouldn't last but a few more days here.
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Old 11-19-11, 11:33 PM   #24
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Thanks for the input. It's a bummer to say goodbye to this bike, but it will be fun looking for a replacement. Looks like a steel frame is coming my way. : )
In the meantime, I'll just stick to my recumbent.
Just don't toss the frame and fork in the dumpster; first remove the components, you may want these some day; then take it to a aluminum recycler and get a couple of bucks for it.

I had a aluminum bike that cracked just like yours did. I never hit anything so the crack appearing was a complete mystery. But that's why I will never ever buy another AL bike...a bit extreme you scream? Maybe, but it's my money, and I don't feel like wasting it on what I consider to be inferior technology for the purpose in which I was using it for.

By the way, I have friend who can repair aluminum, he told me to junk it, all the various method of fixing it wouldn't be worth the expense and still not guarantee it would last and it would look like crap. I decided to scrap it.

Last edited by rekmeyata; 11-20-11 at 12:27 AM.
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Old 11-19-11, 11:55 PM   #25
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Not knowing your abilities or access to tools/equipment, the best choice
is to replace the frame.
It could be repaired by grit blasting the entire head tube, inspect crack(s), grind out the crack, tig weld the head tube and ream bearing fits to the correct size after welding. The paint would be gone, and a very nice weld would adorn your headtube instead of the rei sticker.
The cost of that repair, depending on you locale, could be less or more than a new frame.
For a temporary "fix" if you must continue to ride it, a clamp, should keep the lower part of the head tube from opening up catastrophically, probably won't stop the crack from propigating, and is just delaying the inevitable.
But, if you must use a clamp, use a heavy duty clamp like this,or heavier, not a worm screw clamp.
If you had a friend or neighbor that is a machinist, a shrink on band would even be better than a clamp, but still delaying the inevitable.
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