Indented bar at clamp - safe to ride?
10-19-06, 12:37 PM
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Indented bar at clamp - safe to ride?
All -
I have a pair of Deda Pista 31.8mm bars (6061 aluminum) that have been indented on the rear of the clamp area by the stem. Where the edges of the stem contacted the bars, there is now a fairly significant depression. While I don't believe I over-torqued the faceplate during installation and subsequent re-installations, I guess it was enough to deform the aluminum of the handlebars.
Does anybody have bars that have indented in a similar manner, and if so do you still ride them? I understand that cracks, scratches and gouges become stress risers and that a bar can fail at those points, but the indentations shown below are very smooth, free of sharp edges or burrs. Does this type of deformation also represent a stress riser? Is the larger 31.8mm diameter clamp area less likely to fail because it is stiffer than a 26.0mm diameter clamp area? It is also my understanding that 6000 series aluminum is less brittle than 7000 series aluminum. Does this mean it can more readily accept this type of deformation?
Thanks in advance.
I have a pair of Deda Pista 31.8mm bars (6061 aluminum) that have been indented on the rear of the clamp area by the stem. Where the edges of the stem contacted the bars, there is now a fairly significant depression. While I don't believe I over-torqued the faceplate during installation and subsequent re-installations, I guess it was enough to deform the aluminum of the handlebars.
Does anybody have bars that have indented in a similar manner, and if so do you still ride them? I understand that cracks, scratches and gouges become stress risers and that a bar can fail at those points, but the indentations shown below are very smooth, free of sharp edges or burrs. Does this type of deformation also represent a stress riser? Is the larger 31.8mm diameter clamp area less likely to fail because it is stiffer than a 26.0mm diameter clamp area? It is also my understanding that 6000 series aluminum is less brittle than 7000 series aluminum. Does this mean it can more readily accept this type of deformation?
Thanks in advance.
10-19-06, 12:57 PM
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That honestly doesn't look that bad, but the consequences of a failure are high even though the risk may be low.
If it were my bar, I'd replace it and figure out why it happened so it wouldn't happen again.
If it were my bar, I'd replace it and figure out why it happened so it wouldn't happen again.
10-19-06, 06:10 PM
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If it was a carbon fiber bar you'd already be dead. Examine it for tiny cracks and try to give it a bend. If it feels good to go then it probably is. The good thing about aluminum is that you should get a bit of warning before it fails, which should leave you with one side to steer with as you slow to a stop. Of course if your daily commute features any curb hopping or 45 mph descents...
DanO
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10-19-06, 07:09 PM
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Replace it. As said above the consequences of failure are high. Aluminum typically fails with little or no warning (contrary to said above). Your dental bills will cost alot more than a new bar. Buy a torque wrench or have it installed by a pro. If you can find one.
10-19-06, 07:12 PM
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Originally Posted by ISeeDeadHuffies
Replace it. As said above the consequences of failure are high. Aluminum typically fails with little or no warning (contrary to said above). Your dental bills will cost alot more than a new bar. Buy a torque wrench or have it installed by a pro. If you can find one.
10-19-06, 07:31 PM
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Ditto the above posts. Lose the bar.
