Need to straighten alloy handbars

Discussion in 'The Garage' started by FredRydr, Jul 6, 2013.

  1. FredRydr

    FredRydr Danger: Keep Back 500 Ft.

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    Fellow inmates,

    I have two or three slightly bent OEM BMW handlebars from F800GSes. I took them to a local autobody shop to straighten, but they said they were unable to help me because the bar simply returned to its current shape. I suspect a motorcycle frame shop would be more experienced dealing with these alloys.

    Can anyone recommend a motorcycle frame shop, especially in Pennsylvania or Maryland?

    Fred
    #1
  2. mcma111

    mcma111 Long timer

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    No one in their right mind would attempt to straighten aluminum bars. Once their bent their trash.
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  3. Sevv

    Sevv Been here awhile

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    Aluminum cracks when bent then bent back. Last thing you want is to have them break right through mid turn.
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  4. FredRydr

    FredRydr Danger: Keep Back 500 Ft.

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    A sweeping opinion. If the comment about aluminum even applies, what is the basis of this belief?
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  5. Trialsguy

    Trialsguy Been here awhile

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    Another vote for tossing those to the curb and letting your local scrap metal scrounger take them away. Never, ever trust aluminum bars that have been bent once, let alone twice to get back to the original shape. Scary stuff. I've seen the results of a bar break, and the jagged edge rip open someone's forearm from wrist to elbow as they fell forward and went past the break.

    If the price of replacing them with OEM Beemer bars is a deciding factor (and I would guess that's fairly high), take them to a bike shop and find some aftermarket ones as close to the shape you like for far less.
    #5
  6. broncobowsher

    broncobowsher Long timer

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    Common knowledge in the motorcycle world.
    Plenty of us have unbent stuff as kids (hopefully so dad didn't find out) only to have things fail spectacularly later. It's amazing most of us are still alive. With age come wisdom.
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  7. Jayrod1318

    Jayrod1318 Poster

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    I've worked with alum for the last 13 years. All alloys common in fabrication industry. Just replace them.

    And from dirt bike experience I can tell you for certain you can bend them back, but strength will be compromised significantly. A typical dirt bike scenario plays out like this, bike gets wrecked hard and bars get bent. Trail or campsite fix straightens them out enough to work. Next wreck occurs and the bars bend very very easy. I've never broke any, but they do turn to jello after bending.

    By purchasing a set of bars it's also a good time to adjust your Ergos and get something that you might like better.
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  8. FredRydr

    FredRydr Danger: Keep Back 500 Ft.

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    Replace even if, say, they just need to be raised an inch on one side? There's no sharp bend.

    Thanks.

    Fred
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  9. Motomedic

    Motomedic Over-caffienated Raconteur

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    Quit being a cheapskate, save your own ass.

    Replace them.
    #9
  10. larryboy

    larryboy Chopper Rider

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    I've repaired the old style 7/8 aluminum bars, it took an overhead gantry crane, a huge vise and a big steel table bolted to the floor. The new tapered fat bars might be a challenge, they're pretty tough.

    It's safe and possible, but it's probably cheaper to just replace the bars.
    #10
  11. lnewqban

    lnewqban Ninjetter

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  12. FredRydr

    FredRydr Danger: Keep Back 500 Ft.

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    FYYFF

    Thanks all for your replies. The good news is it turns out this $290 bar is not bent! :clap I just finished removing all the shit attached to the bar, pulled it off and checked it every which way. The rubber bushings under the bar clamps did their job and were twisted until I loosened everything again. (I did that on the road, but apparently not enough).

    Fred
    #12
  13. 2 SPOT

    2 SPOT wannabe

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    not opinion and not belief. its just a fact of a anything thats heat treated,,, times 100 when its an alloy that has been work hardened during a mandrel bending a drawing process.

    the above links are good but heres my lamens easy to understand cliff notes version.

    the alloy is soft at the factory so it can be worked w/o cracking. during the process it gets work hardened and can become brittle if they dont keep things in order, after its all done it goes through a final heat treating process to get that perfect blend.

    when a bar gets bend it gets a localized heat treatment, just like working it at the factory, (brittle) then when you try to straighten it out it goes through the localized process again (more brittle) introducing micro fractures that you cant see but you can hear.

    now you could anneal it, bend it to what you want, then give it a proper heat treating and be golden, but the manufacturer has spent millions over the years on getting this process right.
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  14. Boatman

    Boatman Membership has it's privileges ;-)

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    Throw them away,,,, they are stress hardened and will only get worse with straightening.


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    #14