Broken Handle bars
#1
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Broken Handle bars
So I was on my ride home looking to enjoy a nice Sumer like day in Denver.
Was going down a semi steep hill when all of the sudden, my Soma Sparrow handle bars broke.
needless to say after some road rash, a chewed up brooks Cambium as well as my Sidis, I still don't know what went wrong.
I do have a brake on my fixed gear bike. Stem was torqued to specs.
Any ideas on how to avoid this from happening again
Thanks.
Was going down a semi steep hill when all of the sudden, my Soma Sparrow handle bars broke.
needless to say after some road rash, a chewed up brooks Cambium as well as my Sidis, I still don't know what went wrong.
I do have a brake on my fixed gear bike. Stem was torqued to specs.
Any ideas on how to avoid this from happening again
Thanks.
#2
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Where did it break ? Anyway, townie bars are not designed to take a lot of force, so if you were somehow pushing hard on them that might have been a factor in the failure.
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The handle bars broke at the edge of the stem
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Questions: how many miles on them? Years? Crashes? Rough roads? Did you buy them new or used?
Those Sparrows are aluminum and are not heavy. All aluminum bars can be ridden to failure. The better ones just take a long time. The bars of older, lesser and heavier stock tend to break by bending at either the stem at the outboard edge of the sleeve. Newer, higher strength alloy bars tend to break as yours did.
My experience is that it is best to replace them while they are still in perfect working order.
Ben
Those Sparrows are aluminum and are not heavy. All aluminum bars can be ridden to failure. The better ones just take a long time. The bars of older, lesser and heavier stock tend to break by bending at either the stem at the outboard edge of the sleeve. Newer, higher strength alloy bars tend to break as yours did.
My experience is that it is best to replace them while they are still in perfect working order.
Ben
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That is the point of highest stress in the bar and the sharp edge of the stem may have caused a small crack to form, causing the failure. Anyway, I'd suggest not using a wide bar like that on a fixed gear, where you will be applying a lot of force at the grips. I only use townie bars on my singlespeeds, where I just lightly rest my hands on the grips.
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Just a thought...were the stem's handlebar clamp diameter and the bar [clamp area] diameter matched? If you clamped 26.0 handlebars into a 25.4 stem clamp, and torqued it down, you'd be cutting/etching into the handlebar. That could introduce a failure point...
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The bars are about 8 months old. no crashes. I bought the bars new.
In terms of miles I commute about 250 miles a week.
The stem and bars are 26.0 mm
I think I may go to a 31.8 bar and stem .
In terms of miles I commute about 250 miles a week.
The stem and bars are 26.0 mm
I think I may go to a 31.8 bar and stem .
#10
Your cog is slipping.
#12
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I take a small fine bastard file to the bar clamp area of my stems and round the inner edges. I don't mean sharp edges, I mean the edges. There is plenty of clamping area and I don't need any corner or edge digging into the bar.
Last edited by SquidPuppet; 03-18-15 at 12:41 PM.
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After a quick look
bars are 25.4 Thompson stem is 25.4
I contacted Soma and was asked to send pictures
Will do so tomorrow
Will let you all know the result
In the mean time I am riding some Nitto Rb018 bars
bars are 25.4 Thompson stem is 25.4
I contacted Soma and was asked to send pictures
Will do so tomorrow
Will let you all know the result
In the mean time I am riding some Nitto Rb018 bars
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Wait. Now you are using Nitto RB-018 bars with a 26.0mm clamping diameter with a Thomson 25.4mm stem ? If this is so, you are really flirting with disaster.
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I got a new Thompson stem that is 26.0mm to fit the Nitto bars.
I am still thinking to go with the 31.8 stem and bar combination to avoid the failure again.
I am still thinking to go with the 31.8 stem and bar combination to avoid the failure again.
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Second, people were riding and racing on 25.4mm and 26.0mm bars for decades w/o any problems before 31.8mm became popular. This is not the reason why you had the original failure.
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Last edited by TejanoTrackie; 03-19-15 at 07:50 PM.
#18
Your cog is slipping.
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#20
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That is my problem, I still don't know what I did wrong or if the bars were somehow defective.
Thanks for your help
Thanks for your help
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Are you able to post a picture of your stem and bars? I'd be curious to have a look at this failure. I'm currently running a set of Sparrows with a Cinelli Grammo and a set of shims on my fixed commuter.
#23
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New bars and only 8 months of use? No way this was a fatigue only failure, there must have been a defect with these bars. If you had to replace your bars basically twice a year, pretty sure business wouldn't be very good.
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#24
ABQ
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Pictures were sent to Soma.
No answer yet?
Will let you know what happens
No answer yet?
Will let you know what happens