Snapped bars

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PH
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Snapped bars

Postby PH » 12 Mar 2017, 12:00pm

Had my ride on Friday cut short when my bars snapped off on one side of the stem, no warning and a painful meeting of the tarmac. Typically at the furthest point from home on a 200km DIY Audax :( Thanks to the kindness of strangers, a young couple stopped and couldn't have been more helpful and a passing van driver took me and bike a few miles to the nearest train station. Got proper tangled up with the bike on the way down, no major injuries but feel I've been given a proper going over.
I've never had a bar break, it's not something I'd given much thought to, these were pretty standard straight bars, Kalloy I think, I'm no lightweight, I like long bar ends and often carry a bar bag. I'm considering how much of this contributed to the failure. Google shows up plenty of examples, nearly all failing in the same place. Looking at mine, it certainly didn't happen all at once, part of the crack looks pretty old and would have been just in the stem so not visible even if I'd ever looked.
I'm pondering a few questions really - These bars were about 9 years old, 60,000 miles. I don't think they were over tightened and no previous crash damage,is this likely to have just been fatigue? Do people regularly check for such things? Is it unreasonable to expect such a component to last a lifetime and if so how often do you you change yours? Any thoughts on replacements? There's a lot of choice, standard and oversize bars, 2 and 4 bolt stems... are there better choices? .......I like the look of the Ritchey Classic oversize bar and 4 bolt stem, any thoughts?

reohn2
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Re: Snapped bars

Postby reohn2 » 12 Mar 2017, 12:14pm

Sorry to read of your incident and hope you heal up quickly.
At 60k I think you've had your monies worth but I'd bet there are a LOT more h/bars out there with far more use and abuse than that.
I'd check if there's a sharpish edge on the stem clamp and if so 'soften' it with emery paper so when tightened up it doesn't cause a stress raiser on the h/bars when pushed/pulled on.
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PH
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Re: Snapped bars

Postby PH » 12 Mar 2017, 12:20pm

reohn2 wrote:At 60k I think you've had your monies worth but I'd bet there are a LOT more h/bars out there with far more use and abuse than that.
I'd check if there's a sharpish edge on the stem clamp and if so 'soften' it with emery paper so when tightened up it doesn't cause a stress raiser on the h/bars when pushed/pulled on.

Yes when I get round to it, I'll have a proper look for clues.
Googling bar breakages resulted in finding nearly as many stem failures, so whether necessary or not, I'm intending to change that as well,

Brucey
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Re: Snapped bars

Postby Brucey » 12 Mar 2017, 3:43pm

rotten luck that.

But..... if they are the kind of bars that I am thinking of, where the centre ( typically 1" dia) part is formed by upsetting a 7/8" dia tube, I'm not all that surprised that they broke.

In an LBS near me (that sells a lot of midrange Giant hybrids etc) they have seen several such breakages a year for the last few years. Now Giant appear to be fitting different (incredibly heavy) handlebars to some of their bikes, perhaps because of these breakages.

I took a look at some of these broken bars and on the unbroken side there were cracks, inside the handlebar. IIRC these cracks had evidently been there from the start, because the inside of the cracks appeared to have been anodised along with the rest of the handlebar. I'd suggest that an examination of your failed bars might be similarly interesting/alarming.

BTW I have often thought that if there were a tether (could be made of parachute cord for example) up the middle of a handlebar, a breakage might be less devastating/injurious.

NB some manufacturers (eg Brompton) suggest that you change handlebars (and a load of other light alloy parts too) once every 5000 miles.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

drossall
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Re: Snapped bars

Postby drossall » 12 Mar 2017, 4:30pm

There's been a lot of discussion of this over the years, and a lot of reports. Some would argue for replacing alloy parts after a certain life (maybe 10 years, or so many miles). If I recall correctly (I'm no metallurgist), both usage and time have an effect; in other words, older, little-used parts are not necessarily immune. I've mainly broken cranks of various makes.

The most spectacular, but possibly apocryphal, story I recall is of someone breaking his stem and the top of an Alpine pass. He was unhurt, but couldn't stay up there all night, so square-lashed his bars back on and descended safely :shock:

In reality, I do have bars that have been around for quite a while. Makes you think.

thirdcrank
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Re: Snapped bars

Postby thirdcrank » 12 Mar 2017, 5:03pm

Bearing in mind Brucey's post about internal cracks, I wonder if it's feasible to do some sort of inspection. I have a gadget I bought as an impulse-buy from Lidl a couple of years ago. (TBH, that's how they make their money from me: stocking stuff that looks good but for which I have no real need.) Anyway, this is a tiny inspection camera, mounted on the end of a flexible arm with its own built-in lighting. I'm not sure if the flexibility would be sufficient to get it round the inside of a pair of drops.

drossall
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Re: Snapped bars

Postby drossall » 12 Mar 2017, 6:32pm

I've told this story before, but it makes me cautious about inspections.

As a student, decades ago, I broke a crank in a 3-up. I was probably bearing the scars when I turned up in the physics lab, because my final-year supervisor, who had a passing interest in bikes, sent me off to his colleague in mechanical engineering. Both were fascinated by the idea that a human could have the strength to break a crank, whereas I, of course, knew that it was not uncommon.

The mechanical engineer used a dye test to prove that the remaining crank was completely sound.

It broke within a year.

thirdcrank
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Re: Snapped bars

Postby thirdcrank » 12 Mar 2017, 6:46pm

Isn't the point that an inspection may reveal faults but doesn't prove that there are none or that none may develop subsequently?

drossall
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Re: Snapped bars

Postby drossall » 12 Mar 2017, 7:01pm

Of course. Doesn't really mean that you shouldn't inspect things; it's just that you can still get caught out.

PH
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Re: Snapped bars

Postby PH » 12 Mar 2017, 7:01pm

Brucey wrote:But..... if they are the kind of bars that I am thinking of, where the centre ( typically 1" dia) part is formed by upsetting a 7/8" dia tube, I'm not all that surprised that they broke.


Thanks for the comments, I'm not entirely sure what the above means. Is there something in particular I should be looking for in the replacement?
I think I'm mostly going to put this this failure down to bad luck, even so, if there's something or some way to decrease the odds of a repeat, I'd like to know.

cycle tramp
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Re: Snapped bars

Postby cycle tramp » 12 Mar 2017, 7:02pm

There's a company called Humbert which produce reasonably inexpensive steel handle bars in most styles, and another by the name of nitro who produce some damned expensive items...
..have to admit that I will only use steel 'bars...although I'm not sure how effective my caution is, as I still have alloy cranks and stems...

RJS
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Re: Snapped bars

Postby RJS » 12 Mar 2017, 7:13pm

Cycle tramp, as I expect you know steel bars aren't unsnapable, I had a friend who's (straight steel bars) broke braking down hill, admittedly they were probably quite old, had a broken collar bone as well :(
Cheers, Rob.

irc
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Re: Snapped bars

Postby irc » 12 Mar 2017, 9:45pm

I'm about to replace shifters, cables, and bar tape on my 9 year old Long Haul Trucker. I may just do the bars while I'm at it.

geocycle
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Re: Snapped bars

Postby geocycle » 13 Mar 2017, 8:30am

Sorry to hear of your off. That's one of the failures we all dread as they are so difficult to detect or prevent. I might have to replace mine just in case!

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Mick F
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Re: Snapped bars

Postby Mick F » 13 Mar 2017, 8:46am

Yes, an awful thing to happen. :shock:

The 'bars on the Mercian are original from 1986 but I have no intention of changing them.
Cinelli 64.

I often pull hard and twist them at the same time as testing the brakes and headset. I give them a good hard workout quite regularly and other than flexing and twisting, they remain resilient and strong as does the Cinelli 1R stem.

We had a chap on here some years ago, who professed to change his handlebars every year or so. I asked him what he did with all the discarded ones, because if I did that, I'd have a shedful by now.

He never answered. :wink:
Mick F. Cornwall