Effective way to make a handlebar slightly thinner?

Discussion in 'Airheads' started by mrfortynine, Dec 3, 2012.

  1. mrfortynine

    mrfortynine Adventurer

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    Hello,

    I'm trying to make a chrome handlebar slightly thinner, so that I can fit it to a 92 BMW airhead, which originally comes with 22mm handle bar. The one I'm trying to modify seems only a tiny bit larger on diameter. Does anyone have any suggestion regarding the most efficient method to do this?

    Thanks a lot.

    jia
    #1
  2. griffo1962

    griffo1962 Long timer

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    Unless it's a "Fatbar" then it is 22mm (or the imperial equivalent 7/8") there should be no need to make it smaller......... :wink:
    #2
  3. mrfortynine

    mrfortynine Adventurer

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    7/8" is actually 22.225mm. I tried for about 15 minutes before I gave up. It seems other bmw handle bar parts really don't tolerate that much difference.
    #3
  4. Benesesso

    Benesesso Long timer

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    1" wide belt sander. Use where belt isn't backed up by a platen.

    [​IMG]
    #4
  5. PeterW

    PeterW Long timer

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    I'd be tempted to use one of the fabric backed sanding strips used on power sanders and work it down by hand. Tape off the areas each side.

    Belt sander will do it no doubt, but it's also more likely to overdo it as well.

    Whatever, you will ruin the chrome ?

    Pete
    #5
  6. Daryl_Stamp

    Daryl_Stamp Been here awhile

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    .225 is about .008", taking that much off w/ abrasive is no doubt do-able but doing so uniformly by hand over the width of the 2 clamps seems like a really tall order. Possible to remove the clamping halves & have some one with a mill or lathe to bore out the .008" required? Seems like a big pita either way. May also try setting up a 'turning' arrangement by making clamping block (wood gobbled up with grease) that fits loosely enough to rotate bars around axis of motorcycle clamping bolt then carefully grinding down with abrasive tool of some type. Would aid in more uniform material removal, but still pretty hokey.
    #6
  7. VStromTom

    VStromTom Long timer

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    Maybe working on the clamps would be better than paring down the handlebar? Not sure what the mounting system is on the bike you cite. Seems an enlargement of the clamp could be done invisibly?
    #7
  8. LuciferMutt

    LuciferMutt Rides slow bike slow

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    Jebus just buy handlebars the correct size. Trust me on this -- the amount of time and effort required to get the ones you have to fit will far outweigh just spending some $ on the right ones! Quit while you're ahead!

    I'd also be somewhat worried about the decrease in bar strength from thinning the walls.
    #8
  9. GearHeadGrrrl

    GearHeadGrrrl Been here awhile

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    No point in buggering up a part to make it fit when the right size part isn't that expensive.
    #9
  10. mrfortynine

    mrfortynine Adventurer

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    Thank everyone for the advices. After trying a bit more, I decided to give up. That said, its actually quite difficult to 22mm M bar (some call it clubman) here in US.
    #10
  11. GearHeadGrrrl

    GearHeadGrrrl Been here awhile

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    When I tried to fit my favorite bar off my Yamaha RD400 to my BMW airhead. Put the 7/8" bar back on the RD and bought a proper 22 mm. Fehling bar for the airhead.
    #11
  12. mrfortynine

    mrfortynine Adventurer

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    Interestingly, the bar i got is from Fehling. On their website, it says "22mm (7/8")". So I took my chance. Well.
    #12
  13. GearHeadGrrrl

    GearHeadGrrrl Been here awhile

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    I think they sell some of the same bar shapes in both sizes...
    #13
  14. Box'a'bits

    Box'a'bits In need of repair

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    I have filed & sanded down the bars twice now to 22mm. Doesn't need to be precise. Generally the bars I use (Protaper & Sunline) are knurled on the clutch side (& fatter), & smooth on the right. Be careful not to use any force sliding on the clutch perch, as this fractures easily. I've found that the right (throttle) side needs no work.

    I've got fat bars on Rox Risers on Gus. They taper down to normal sizing anyway. I crashed fairly heavily last week, & they stood up to that well.
    #14
  15. boxerkuh

    boxerkuh Been here awhile

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    Only place where I have found decent BMW 22 mm bars is from Flanders handlebars in California. Great stuff. I have always been told that it is much easier to "ream" out the controls to fit a 7/8 bar than to make the bar smaller.
    #15