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~ B A D A S S ~
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Discussion Starter · #1 ·
I wonder whats the cheapest way of bending tubes are, I mean if I don't want to buy a special tube bender of some sort. I just want to be able to bend a few different diameter tubes. And its not for any type of mass production. Like 2 chainstays, 2 seatstays, a top tube etc.

Also when bending very large radiuses, what will work? Like from the headtube to the rear hub like some "retro" double top tube bike has.
 

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After years of messing around with benders and getting poor to mediocre results I finally dropped a grand on a Di-Acro 2 and now realize I still need the Quick Lok Clamp which will cost another $500. So... there's really no cheap way to do it yourself.

-Joel
 

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After years of messing around with benders and getting poor to mediocre results I finally dropped a grand on a Di-Acro 2 and now realize I still need the Quick Lok Clamp which will cost another $500. So... there's really no cheap way to do it yourself.

-Joel
Joel, if you only paid a grand for the setup you have with all those dies then I would say you did well!

Knowing you I would say that you could build more than a passable quick lok yourself.
 

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~ B A D A S S ~
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Discussion Starter · #7 ·
I had a look at that di-acro 2. What diameter tubes can you bend with it? Also what is the smallest and largest radius it will make? Do you put some kind of mandrel inside to get good bends?

I'm thinking at diying something to be used with a hydraulic press and maybe make some type of mandrel to not squash the tubes.

Do you have any detailed photos of the acro 2?
 

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Joel, if you only paid a grand for the setup you have with all those dies then I would say you did well!

Knowing you I would say that you could build more than a passable quick lok yourself.
Cheap Quick Lok Clamp here we come:

1 1 pack 91251A020 Black-Oxide Alloy Steel Socket Head Cap Screw 1/2"-20 Thread, 2" Length, packs of 10 $11.25 pack
2 4 each 94815A108 Plain Steel ACME 2G Hex Nut Right-Hand, 5/8"-8 ACME Size $2.80 each
3 1 each 98935A724 Plain Steel General Purpose ACME Threaded Rod Right Hand, 5/8"-8 Thread, 1' Length $6.38 each
4 1 each 98890A119 Malleable Iron General Purpose ACME Hndl Nut 5/8"-8 ACME Size $13.26 each
5 1 each 8910K934 Low-Carbon Steel Rectangular Bar 1/2" Thick, 1-1/4" Width, 1' Length $9.54 each
6 1 pack 98099A034 Black-Oxide Steel Thick Flat Washer 1/2" Screw Size, 1-1/16" OD, .17"-.2" Thick, packs of 5 $5.33
 

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Stokeless Asshat
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Cheap Quick Lok Clamp here we come:

1 6 pack favorite beer
1 1 pack 91251A020 Black-Oxide Alloy Steel Socket Head Cap Screw 1/2"-20 Thread, 2" Length, packs of 10 $11.25 pack
2 4 each 94815A108 Plain Steel ACME 2G Hex Nut Right-Hand, 5/8"-8 ACME Size $2.80 each
3 1 each 98935A724 Plain Steel General Purpose ACME Threaded Rod Right Hand, 5/8"-8 Thread, 1' Length $6.38 each
4 1 each 98890A119 Malleable Iron General Purpose ACME Hndl Nut 5/8"-8 ACME Size $13.26 each
5 1 each 8910K934 Low-Carbon Steel Rectangular Bar 1/2" Thick, 1-1/4" Width, 1' Length $9.54 each
6 1 pack 98099A034 Black-Oxide Steel Thick Flat Washer 1/2" Screw Size, 1-1/16" OD, .17"-.2" Thick, packs of 5 $5.33
Fixed it for ya.
 

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RCP Fabrication
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389 Posts
If you are looking to do large radius bends, for a top tube or something another option my be to get a cheap tubing roller. The harbor freight ones are actually supposed to work pretty well. Tubing Roller
 

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Bike Freak
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If you want to go quick and dirty, I used a couple of 2x12's that were bolted together, had a radius cut into them on the bandsaw and then routed out a 5/8" groove down the center. With that method I was able to bend the top tubes and seat stays for this frame.

The biggest issue was getting consistent repeatable results.
After that I purchased the Harbor Freight tubing roller and with the "Swag" rollers it works great. (the stock ones that come with it are garbage)
 

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After years of messing around with benders and getting poor to mediocre results I finally dropped a grand on a Di-Acro 2 and now realize I still need the Quick Lok Clamp which will cost another $500. So... there's really no cheap way to do it yourself.

-Joel
It seems with these you either get the quick lock or dies. With mine I have the lock, but it came with dies that were of no use to me.

Drew has the sweet setup, but he's a tool sluuuut.
 

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I wonder whats the cheapest way of bending tubes are, I mean if I don't want to buy a special tube bender of some sort. I just want to be able to bend a few different diameter tubes. And its not for any type of mass production. Like 2 chainstays, 2 seatstays, a top tube etc.

Also when bending very large radiuses, what will work? Like from the headtube to the rear hub like some "retro" double top tube bike has.
I'm not an expert but I've been trying to figure out this same question for awhile now...what benders bend what diameter tubes and for what parts of a bike.

It seems to me that the *cheapest* way involves the most labor/TIME/sense of satisfaction & accomplishment (and frustration just prior to that) by the builder.

If you're using thin walled heat treated stays instead of straight gauge 4130 from Aircraft Spruce or the like, you will need to find out what works and doesn't for creating dimples and flat spots in the tubes. If you're using 16mm seat stays, the same bender won't likely work for 19mm chainstays or whatever you're going to use since the radius is tighter on chainstays than seatstays.

I get a headache trying to figure out what to get because what it comes down to is that you need MULTIPLE benders depending on what you want to bend. You want to get large radius bends in your top tubes? Then get the cheap Harbor Freight (HF) roller suggested above and the SWAG dies for 28.6 tubes or 31.8 tubes.
You want to bend your own seat stays? The cheapest way is to make a wood mandrel with a router with something like a 7 or 8" CLR, and either "V" notch it for tubes or use an end mill, and then figure out the best way for the tubing guide. Lots of well-known builders use their own creation for single bend seatstays it seems to me.
Bending chainstays? I have no clue since I buy pre-bent chainstays and just dimple them myself.

The less cheap way (money, not time) is to go buy the right tools, i.e., the Mr. Bendy from Anvil or whatever that sweet thing is called...for the stays. A great deal actually when you consider it's made for bike builders whereas most the other tubing benders are for car roll-cages or planes or whatever. Pro-Tools makes a better large-radius bender than HF but it's almost 10x the cost.

So anyways, if you want to bend tubes be prepared to spend a bunch of time learning how to do it (and going through lots of tubes) no matter if you make or buy tooling. You'll spend a lot more time if you make all the tooling yourself but it'll be way cheaper (*if you don't include an 'hourly rate' for your time) and probably more satisfying.

I've been wondering if anyone has tried THIS bender...? It's very well priced for the number of die sets and it could be something good to learn on before "graduating" to a $1000 Di-acro or something else.
 

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Let's get weird
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This was done on the cheap with what was on hand. Red Oak die that was left over Lazy Susan material, roller blade wheels that were on their way to the trash, and steel drops from the overflowing shop bucket.

The channel specifically fits a 7/8" tube and the wheels were turned in the lathe to form a 7/8" groove when put together. It will put slight waves on the inside of the bend when pushed to far and fast (.035" > 17degree), but I freeze the tubes with soapy water before bending to help out and dimpling the tube right on the inside bend gets rid of the waves. The deformation could be better controlled if the drawbar was anchored on radius center.

I've bent 5/8" .035" in a pinch and the results weren't terrible. The base was designed to allow easy swapping of different dies for different tube sizes, which I'm hoping to get around to sometime soon along with correcting the draw bar position.


 

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I've been wondering if anyone has tried THIS bender...? It's very well priced for the number of die sets and it could be something good to learn on before "graduating" to a $1000 Di-acro or something else.
Looks the same as this from fleabay. I've seen it for <$100 but that was awhile ago. Can do single bends of seat stays okay, but will leave dimples in the end, so no way to do s bends without having to fill a dimple, which just seems wrong to me.
 
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