Which pipe or tube to use?

[sarrix]

Hi all,
I'm building a kart/buggy based on an old ATV (Suzuki LT230e). I'll be using the front suspension as-is, likewise the rear swing arm setup (and relocating the engine over the rear swingarm); and i'll be getting rid of everything in between.

Obviously the length will increase fairly significantly, and I'll be keeping the both the upper and lower rails (by keeping, I mean replacing with longer but keeping the position for rigidity).

The existing frame is all 1 inch (OD), and I'll keep that standard, so the question is, what should I be using? Tube (DOM)? Pipe?

Given that it will take some abuse off road, and the length increase, should I really be considering something more than 1 inch?

Thanks for any advice

 

[DJEEPER]

DOM is good stuff. Thats what my jeep's roll cage is made of and it is some very hard steel. Definitely will work for you.

 

[Acavet]

You don't want to use pipe, its not intended to be used as a structural component.

Pipe is measured differently with the diameter indicating the internal dimension.

Tubing on the other hand is measured by its exterior dimension.

D.O.M. stands for drawn over mandrel, referring to the way the tubing is formed. A piece of flat metal is rolled and fused together to produce a tube, its very easy to distinguish because it will have a seam running the length of it. It is the least expensive of all tubing and is more than adequate for what you want to do.

 

[landuse]

Rather use tubing IMO

 

[OzFab]

Given the added length & amount/type of abuse, you may want to consider 1 1/4" - 1 1/2" but, don't use thicker wall, that will only make it heavy...

 

[sarrix]

Thanks for the opinions, DOM it is. i wouldn't normally have considered pipe, but this article (title at least) infers pipe would be a better choice. I think it's just the way it's worded.

Anyone have experience of bending say 1-1/4 DOM in a HF pipe bender? aside from the die sizes, I see no reason why it shouldn't do the job (max 90 degree bends). Am I missing anything?

 

[devino246]

Thanks for the opinions, DOM it is. i wouldn't normally have considered pipe, but this article (title at least) infers pipe would be a better choice. I think it's just the way it's worded.

Anyone have experience of bending say 1-1/4 DOM in a HF pipe bender? aside from the die sizes, I see no reason why it shouldn't do the job (max 90 degree bends). Am I missing anything?

Standard welded seam tubing would work just as well, and save you some money.

A pipe bender will just crush tube.

 

[DJEEPER]

I used three well placed trees for my bending needs

Worked great!

 

[OzFab]

Anyone have experience of bending say 1-1/4 DOM in a HF pipe bender? aside from the die sizes, I see no reason why it shouldn't do the job (max 90 degree bends). Am I missing anything?

It's called a pipe bender for a reason, it's for bending pipe! If you want to bend tube you need a tube bender like this:

 

[JoesEdge]

It's called a pipe bender for a reason, it's for bending pipe! If you want to bend tube you need a tube bender like this:

I saw this post and I was like "I've never seen a bender like that." Then I realized that you're in Australia. Different stuff down there I guess.

I have a JD2 Model 32 bender. JD2 Model 32 It's a beast, but not cheap. It'll run about 1,000.00 (US) with 1" 180 degree die shipped to you door.

Pro-Tools is another popular manufacturer of fabrication tools.

These tools are used often by fabricators in the off-road industry. I'm talking Baja 1000 type fabricators.

 

[KartFab]

Ok I usually don't chime in on things I don't know much about, but... (that was my disclaimer).

I saw this guy on you tube use a harbor freight pipe bender to bend tube. He just used a smaller die (eg 3/4" die on 1" tube)) the tube looked like it was not going to fit at all until it bent the sides first, then it slipped right in, then bent really nicely w/ no kinks. It looked really good after the bend was finished, even did a 90 deg bend with it no problem.

If i were going to bend tube, i would either:
1) pay someone else to do it
2) get a real tube bender

11-14 gauge would be my guess for wall thickness?

 

[dnuccio]

personally i think DOM would be overkill. we're not building rock crawler suspension links here, its just a go kart.

 

[OzFab]

I saw this post and I was like "I've never seen a bender like that." Then I realized that you're in Australia. Different stuff down there I guess.

Ok I usually don't chime in on things I don't know much about, but... (that was my disclaimer).

I saw this guy on you tube use a harbor freight pipe bender to bend tube. He just used a smaller die (eg 3/4" die on 1" tube)) the tube looked like it was not going to fit at all until it bent the sides first, then it slipped right in, then bent really nicely w/ no kinks. It looked really good after the bend was finished, even did a 90 deg bend with it no problem.

If i were going to bend tube, i would either:
1) pay someone else to do it
2) get a real tube bender

11-14 gauge would be my guess for wall thickness?

I've seen it too & other guys swear they can do it but, after trying it myself (1" tube with a 3/4" die, fill the tube with sand, you name it, I tried it) & having no success, I decided it's better to use a tube bender.

I wish I had bent my frame myself but, it was cheaper to have it made than to buy even a cheap tube bender

 

[sarrix]

Thanks for the input guys. I went with mild steel in the end, agreed DOM is better, but overkill for this application.
I used 13g (0.095 wall) 1 1/4" tube which slid nicely over the old 1" tube where appropriate. Worked out well.

I did use the HF pipe bender, and while I couldn't quite get a full 90 degrees without it looking like it was about to kink, I got close, and I quite like how it came out. I just wish the fish mouthing had been as easy, I struggled getting the angles right.

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And I also made a mockup seat of the kirkey's I plan to buy so I can shape the rollbar correctly:

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Next job is the engine mount, awkward because the rear swingarm is aluminium so I can't weld it.