Cold bending 1 piece cranks?

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maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
Impressive fab skillz there dude! Using whats available is good old-fashioned 'merican ingenuity!usflg
 

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
Brilliant Wayne! Gonna make one. Thanks, big time.

Side note. Years back was reading this excerpt from a WWII Vet. He was asked "How did you do it?" He replied; "Didn't know we couldn't. So just went ahead and did it"

Is one of my favorite mantras in life.

.flg.
 

atombikes

New Member
Feb 14, 2010
525
2
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Northern VA
Nice result.

You mention using "low heat" in a prior attempt. What was the heat source? Propane torch? MAPP gas torch? Oxy-Acetylene torch? Also, what kind of tip on the torch?

If using heat, shouldn't I just be able to slip a pipe over the crankarm and bend to desired angle (no jig required)?
 

wayne z

Active Member
Dec 5, 2010
1,743
5
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louisiana
I used an aceteleyne torch with a #2 tip. This puts out enough heat to quickly get it to a dull red for bending. A propane or mapp will take much longer and the BB will have time to absorb more heat, but might work if you remove the crank from the bike.
 

dracothered

New Member
Jul 25, 2012
973
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Howell, MI.
I used an aceteleyne torch with a #2 tip. This puts out enough heat to quickly get it to a dull red for bending. A propane or mapp will take much longer and the BB will have time to absorb more heat, but might work if you remove the crank from the bike.
I think if you have a Mapp gas with Oxygen it will heat as fast as the acetylene.
 

wayne z

Active Member
Dec 5, 2010
1,743
5
38
louisiana
Nice result.

You mention using "low heat" in a prior attempt. What was the heat source? Propane torch? MAPP gas torch? Oxy-Acetylene torch? Also, what kind of tip on the torch?

If using heat, shouldn't I just be able to slip a pipe over the crankarm and bend to desired angle (no jig required)?
Yes, when I used heat, I used just a pipe to bend with.