Tips on bending pipe, or making a pack rack thing

[xwhatsit]

Welding bits together typically looks like arse on a naked bike, though. It would even show through black coating?

Attached is the kind of look I want to avoid.

P.S. sorry about the minor thread highjack. I suppose it's somewhat relevant

[imdying]

Then just make them up like that, and have the 3D scanner/pipe bender thingy make them out of a single mandrel bent piece

If I were bending up a subframe like you're talking about (and I will be, for that same purpose as you), I'd be using either the 1/2" or 5/8" pipe bender I have

[imdying]

These ones are made from seperate pieces.

[Steam]

Attached is the kind of look I want to avoid.

I wonder how Britten did his sinuous intestine ones? Is that the kinda seamlessness you are going for?

[Ocean1]

I've used 5/8" hydraulic tube for racks, if you've got the right bender it's a snap. If you haven't it's invariably ugly.

I wonder how Britten did his sinuous intestine ones? Is that the kinda seamlessness you are going for?

A local guy's been making very tight exhaust-tube-dimension doughnuts for ages, you just cut the req'd pieces and weld 'em up. It's the only way you can really get sweet curves without seriously expensive tooling. Prety sure they're available from some of the auto-distributor places.

[geoffm]

An exhaust shop can bend tube for you - our locla charges $5/bend IIRC. You can also buy premade bends - Staniless Alloys do stainless ones.
The $200 pipe benders that use a 10T jack don't work on exhaust tubing - they are made for water pipe. Work well for that though, if you don't mind the extra wall thickness
Geoff

[scumdog]

You can pour dry beach sand into the pipe. Pack it lightly, and cap it with wood plugs.
Heat and bend the pipe/tubing with an oxy set, paying attention to add more heat to the outside of the bend. The sand stops the pipe collapsing while the metal reshapes itself. Great way to make complex header pipes from scratch.
Plus its cool to brag about your artistic bending skills.
An Orange glow on the metal is a sign that its close to bending temp.

ALWAYS always make sure the sand is as dry as a camls back..Any moisture MAY flash-steam when it's heated and MAY cause a filling of the Y-fronts (and worse) when the expanding steam splits the pipe.

[sAsLEX]

These ones are made from seperate pieces.

Saw a wastegate pipe once on a "really big bike...." that was made out of 27 odd triangular pieces of metal bent and welded, looked immaculate. There is no end to what the talented can do!

[Ixion]

Don't use beach sand unless you have no choice. It's very hard to clean the salt residue from the inside of the pipe afterward, and it can cause subsequent corrosion. Get some salt free dry sand from a builder's merchant.

[AllanB]

I wonder how Britten did his sinuous intestine ones? Is that the kinda seamlessness you are going for?

I read that each set of pipes took him 40 hours to make by hand. Lots and lots of little curves & cones all welded together.

I wonder if his kids ever saw him........

[AllanB]

Pipe below, the second picture took the bend out of my pipe......

[offrd]

I used solid bar for the ones i just whipped up this morning, Bits of flat bar for tabs to bolt to the bike, Mig and used gas to do the bends.. Easy as!

Not worth a million bucks but do the job!

Photos here http://www.kiwibiker.co.nz/forums/at...6&d=1199496821 http://www.kiwibiker.co.nz/forums/at...7&d=1199496821

[xknuts]

Simplest and most effective way is to hire a manual pipe bender from your local hire shop. Try your local pipe supplier for hydraulic pipe and bend away happily.

Thank you

ask any HVAC engineer.

But whats HVAC??

ALWAYS always make sure the sand is as dry as a camls back..Any moisture MAY flash-steam when it's heated and MAY cause a filling of the Y-fronts (and worse) when the expanding steam splits the pipe.

Is that like a brown eye in the Y fronts? Good advise, Scummy

[rwh]

But whats HVAC??

Heating, Ventilation and Air Conditioning

Richard

[Bass]

I used to design and build tuned pipes just cos I could. I was pretty anal about cross sectional areas, ground clearance, weight and stuff like that and so almost never used bends done in a commercial bender of any sort. Basically the bending dies are never a good fit for the tube that YOU want to use and so the pipe is crushed to some degree. However, if that doesn't matter to you, the simplest way is to buy commercially done bends, then cut and weld to suit.

If it does matter, then the sand AND HEAT method mentioned in here, including all the advice about sand selection, is the most versatile method because you can have any reasonable radius that you want or even any change of radius along the bend, if you so desire. Also you can take a fairly long length of pipe and sculpt it pretty much any way you please.
Further, this technique is quite easy to teach oneself and you will get proficient quite quickly. You will also find that a butane torch run off your barbecue gas bottle is adequate for small diameter or thin walled tubing. You can teach yourself to braize (sp) (not weld) aluminium with it too and do the whole thing in ally if you wish. There is a huge range of ally tube available out there. I recommend Weldwell Allyflow if they still make it, as the braizing rod. I got so I could braize 4 thou beer can with that stuff.
No matter how you go about it, note well Triboy's comment about more heat on the outside of the bend.