Bending chrome molly tubing? (1 Viewer)

[Soul_Man]

Trying to bend some 1 1/4" chrome molly tubing to make a custom bicycle. It wrinkles on the inside and stretches/flattens on the outside radius of the bend. No problems doing mild steel.

Can I heat the tube to get it to bend right? Would I have to get it red hot (just bought and oxy-acetylene set but don't have tanks yet )? Any other tips on bending the stuff?

Not sure if this is the right forum, but figured if anyone would know they'd be on here.....

 

[Rocinante]

Assuming you're using reynolds or TT tubing or something like that, if you heat it to bend your going to weaken it significantly I would think. That stuff is tempered and also pretty thin. I'm not sure how the pros do it. There are some frame builder forums you might want to google for. Try this site for starters http://www.phred.org/mailman/listinfo/framebuilders

 

[Poser]

What kind of bender/dies do you have?

 

[bustanutley]

heating the tubing gets rid of the reason to use chromally, it will change its properties, however, after welding the stuff you have to heat treat the stuff anyway so that may be an ok route. As far as the bender messing it up, if it is a quality unit I would think it should bend thin wall tube just fine? granted the tube is the correct size?

 

[lowtideride]

If it turns out you are using a harbor freight pipe bender it will just destroy the tubing. You are welcome to take a stroll down and use our JD2 tubing bender. Only die we have is a 5.5 1.75 though so you'll have to buy tubing to match...but your welcome to it.

-Al

 

[LC_Hamma]

Fill the tube with sand, compact it, & cap both ends. I just bent up some 1 1/2" 1/16 wall DOM for my headers on my 55. I could only bend almost up to 90 deg. w/o any deformation of the tube. I'm using a JD Squared manual bender.

 

[Soul_Man]

Thanks for the replies guys!
I'll try to avoid the heat route, and I may try the sand method.

I'm using this bender: http://shopoutfitters.com/TubeBender3.html which I think is a pretty good bender with good dies. It does my mild steel 1 1/4" real nice, just the chrome molly that I'm having problems with....