Purposefully bending seatposts?

[XCDave]

Hello all,
Odd question, but I'd like to bend a seatpost through about 90 degrees for a rat-bike project I've got on the go. My question is, can anyone recommend if this might be achievable with some plumbers pipe bending thingy? Or are there any other options? Or is it just not going to work?
The seatpost in question is one of those traditional steel jobbies with the separate clamp that crimps around the top. It's fairly chunky, certainly thicker than plumbing tubing.
Any advice greatly received!
Ta,
D.

 

[B3]

Re:

Bend an existing seatpost? No, you need a mandrel bender, as the plubers type will colapse the inside wall. Mandrells come in a certain range of sizes that don't match 99% of seatposts, and a certain bend radius to suit the tube size, so the post will probably be too short to hold and bend. You're better off buy a laid back BMX one and shimming the frame to suit that.

https://www.ebay.co.uk/i/233142000965?c ... gKORvD_BwE

 

[XCDave]

Re:

Thanks for the knowledge B3. I've got one of those BMX posts in an existing rat rod I've done, but the problem is the brace means it sits quite high out of the frame and I want a real low-slung, set back position on this one.
Maybe back to the drawing board then.
Thanks again,
D.

 

[greencat]

Saw and reweld?

 

[B3]

Re:

Yeah, as Greencat says, you could lobster back it

 

[XCDave]

Saw and reweld?

Considered, but disregarded as I've never welded and would have to buy some welding equipment! But it looks like I might be able to get a friend to do the honours.
Awesome creation above though!
Thanks for the help peeps.
D.

 

[Bimly]

I'm not entirely sure I would risk my butt on a 90o welded alloy seatpost. Alloy is a bitch to weld at best, due to its immediate corrosion when cut. Structurally your on very risky ground and its the good reason alloy posts are bent not welded! From an engineering POV I would suggest putting a steel plug inside the 2 bits then welding if you must use thus route. This could be solid bar the same dia as the Id of the seatpost.

Why not make it from steel bar..?.it could be as crazy a shape as you like ! If somewhat heavier,!

 

[ishaw]

Re:

Sounds like you need one of these:

https://rover.ebay.com/rover/0/0/0?mpre ... 3198145002

 

[XCDave]

Re: Re:

Sounds like you need one of these:

https://rover.ebay.com/rover/0/0/0?mpre ... 3198145002

That would be exactly the thing, but it's too girthy!
I had also considered the steel bar approach, but the cost of getting one specailly made (again, I have no equipment for this) made it a bit extravagant.
Cut and (get a friend to) re-weld seems the best option - it is a steel post so this should be fine.
Thanks for all the help peeps!