# Hydroforming and the future of the round tube?



## mtroy (Jun 10, 2005)

The most recent rides on hydroformed alu HTs (all 29ers, if it matters) has been pretty impressive as far as ride quality VS stiffness, etc. It has me wondering if the regular round, butted alu tube is becoming a bit out of style.

I have always thought that the best thing about carbon is the ability to really fine tune the characteristics of a particular section of the frame by laying the carbon down in certain ways, going far beyond the abilities of a simple butted, ovalized tube.

I see hydroformed alu as approaching that ability to tune with the cheaper material that alu is.

But, I am not that educated in the engineering aspects of it all, I just have been pretty impressed with riding the results. Is hydroforming the future of alu and if so, what will happen to the smaller builders who offer more expensive, handmade alu bikes with regular round tubes?

Just wondering.


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## pvd (Jan 4, 2006)

Round tubes suck. I wish I could get butted hydroformed tubes just like I wanted. Ha!


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## AZ (Apr 14, 2009)

You have seen the future , and the future is now .


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## DWF (Jan 12, 2004)

Round tubes will never die. But just in case, I patented my P.I.S.T.A. tubeset years ago and have several ongoing infringement lawsuits....


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## DWF (Jan 12, 2004)

BTW, hydro-forming is more about ease of manufacturing & marketing than it is engineering. Swoop sells.


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## mtroy (Jun 10, 2005)

DWF said:


> BTW, hydro-forming is more about ease of manufacturing & marketing than it is engineering. Swoop sells.


Interesting statement. Why is the process and expense of hydroforming a section of frame easier than drawing a butted tube?


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## Schmitty (Sep 7, 2008)

DWF said:


> Round tubes will never die. But just in case, I patented my P.I.S.T.A. tubeset years ago and have several ongoing infringement lawsuits....


Tell us more.

-Schmitty-


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## AZ (Apr 14, 2009)

mtroy said:


> Interesting statement. Why is the process and expense of hydroforming a section of frame easier than drawing a butted tube?


IMHO , the process is not easier , hydroforming allows the manufacturer to obtain shapes and profiles not easily obtained with drawn tubing .


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## BadHabit (Jan 12, 2004)

DWF said:


> BTW, hydro-forming is more about ease of manufacturing & marketing than it is engineering. Swoop sells.


Bought the swoop. Just got a hydroformed 2009 BMC FS02 frame--the sections of DT and TT are maximized where they intersect with ST and HT. TT is also shaped into a "T" shape. All looks very strong. 5.08 lb frame.


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## SuspectDevice (Apr 12, 2004)

Drawn over mandrel cold-worked domed, flared, and squished aluminum tubing is worlds better than hydroforming.

Not only is it clean enough to be done in a country with stiff environmental regulations, it has a superior ride quality for non-suspension bikes, it's much cheaper to tool up for.

On top of that, for most applications a round tube is hands-down the most efficient structure.

For an idea what's possible with simple doming, flaring and squishing, take a look at any of the more tubular Intense frames. Those tubes are cold-worked.

I am only interested in making bikes out of domestically made tubing. I'm never going to be able to do that with hydroformed tubes, nor do I want to.


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## mtroy (Jun 10, 2005)

SuspectDevice said:


> Drawn over mandrel cold-worked domed, flared, and squished aluminum tubing is worlds better than hydroforming.
> 
> Not only is it clean enough to be done in a country with stiff environmental regulations, it has a superior ride quality for non-suspension bikes, it's much cheaper to tool up for.
> 
> ...


That is an interesting response. Thanks! It seems to me that a bicycle is both simple and complex in that it works pretty darn good with just a few sticks of steel tube glued together and then you go ride...and on the other hand....it needs to be pedaled efficiently, ride well, be stiff where it should be and compliant where it can be, not break before its time, be as light as is prudent....and all this is happening in different parts of the frame in different ways. I am no engineer, but I sure cannot see how a shaped tube is not better in this regard: meeting the specific needs of the moment in that place it lives within the structure.

Heck, I ride a steel SS HT frame most of the time and it is still a fun, simple thing to ride. But the last two HT alu frames I have ridden...the Giant XTC and the Scott Scale...were smoother or as smooth as my Jabberwocky and were lighter and just as stiff. I am not sure if I would be riding them 5 years later like I expect the steel frame to do, but most folks don't keep their bikes that long anyway.


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## brant (Jan 6, 2004)

pvd said:


> Round tubes suck. I wish I could get butted hydroformed tubes just like I wanted. Ha!


How about externally bulge butted super cool steel tubes?


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## golden boy (Oct 29, 2008)

Excellent question, mtroy! I have noticed the hydroforming trend and I've just kind of assumed that, as DWF put it, "swoop sells." As a degreed industrial designer, I certainly understand sex appeal in product marketing. Is there more to hydroformed tubes than that? I'm hoping more custom builders weigh in on this topic. In the meantime, it's high time I engage in some internet research on the hydroforming process...


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## mtroy (Jun 10, 2005)

golden boy said:


> Excellent question, mtroy! I have noticed the hydroforming trend and I've just kind of assumed that, as DWF put it, "swoop sells." As a degreed industrial designer, I certainly understand sex appeal in product marketing. Is there more to hydroformed tubes than that? I'm hoping more custom builders weigh in on this topic. In the meantime, it's high time I engage in some internet research on the hydroforming process...


Thanks. I know that a lot of things are marketing driven but I find some of the new shapes in frames dead sexy and some just dead. I would like to hear from more builders as well.


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## DWF (Jan 12, 2004)

BadHabit said:


> Bought the swoop. Just got a hydroformed 2009 BMC FS02 frame--the sections of DT and TT are maximized where they intersect with ST and HT. TT is also shaped into a "T" shape. All looks very strong. 5.08 lb frame.


BH is that really you? What's going on? :thumbsup:


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## DWF (Jan 12, 2004)

Schmitty said:


> Tell us more.
> 
> -Schmitty-


P.I.S.T.A. = Proprietary Infinitely Sided Tubing Array.

It's a joke I started when Litespeed came out with their latest "proprietary" 25 sided tubes around the turn of the century. I can't remember what they really called it but it struck my funny bone next to my ridiculous joint.

Infinitely Sided = Round.


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## Rody (Sep 10, 2005)

"I would like to hear from more builders as well."

From an engineering standpoint, it's tough to beat the round tube for... stress distribution in a bicycle frame, control of wall tolerances and butting, and efficiency of production.

I, much like DWF, see market trends ebb and flow and hydroforming is the latest lace panty to get a rise out of the bicycle consumer.

As for practical experience...I've got 4 Al frames in the shop for repair in the last 4 months, ironically all hydroformed tubed pieces. YMMV.

rody


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## BadHabit (Jan 12, 2004)

DWF said:


> BH is that really you? What's going on?


Struggling to answer even simple questions, it seems.

P.I.S.T.A.--*laugh*

Gonna dump a load of silly parts on that Illinois BMC...or I was.


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## mtroy (Jun 10, 2005)

Rody said:


> "I would like to hear from more builders as well."
> 
> From an engineering standpoint, it's tough to beat the round tube for... stress distribution in a bicycle frame, control of wall tolerances and butting, and efficiency of production.
> 
> ...


Your point is well taken in this regard; the frames yet have to prove themselves.

But, is it not true that some market trends have a tendency to be the way things are done in the future, not just lace panties, but the next pair of blue jeans?

I remember early, butted, lightweight alu bikes like the Yeti and the Manitou with the Program tubing. They were not exactly bulletproof.

It does seem to me that the possibility to make a superior frame with hydroforming can just as easily become a possible breakage nightmare if function follows form.


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## verticult (Jan 18, 2005)

mtroy said:


> Your point is well taken in this regard; the frames yet have to prove themselves.
> 
> But, is it not true that some market trends have a tendency to be the way things are done in the future, not just lace panties, but the next pair of blue jeans?
> 
> ...


The early Yeti was around 4 lbs with only the three main butted. The headtube with straight .155 wall as was the BB. The stays were nearly straight gauge with 5/16 dropoouts. It was extremely light for the day, and the first or second revision of a pioneering technology was vastly superior to any period technology. Many frames of the era would fail if you looked at them.

From straight gauge tube I build, perhaps the stiffest trials frame on the market, a 3.25 lbs XC race frame that I have experienced zero failures (now four years of production) a 8" DH frame that weighs around seven pounds that has been, so far very durable. I can't imagine anyone "engineering" a frame using any current popular shapes. Hydros are for stylists, not engineers.


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## CroMoHo (Oct 20, 2009)

To hell with hydroformed tubing! It's all ****! Same goes for shotpeened crap!


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## themanmonkey (Nov 1, 2005)

IMHO it all comes down to money and brand identification. Historically bike companies have used some kind of "gimmick" to differentiate their bikes from everyone else without looking at the decals, look back at Bates and Hetchins as good examples. The Biggies can throw money at a process that prices all of us and most other medium sized folks out of the equation. In the end when you see that frame that's been stripped of paint or covered in stickers and can still tell who made the bike that's the business part of the industry.


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## mtroy (Jun 10, 2005)

Interesting comments, and not quite what I expected (although I am not too surprised). I have to speculate here, cuz I do not know this for sure, but I doubt that there is a complete lack of engineering behind the formed tubes. Surely a manufacturer seeks to make their product unique and hydroforming does do that visually, but I think saying that it is all marketing driven does not stand up.

And one reason I say that is the existence of so many shaped forms in other types of engineered structures. They are not all round and butted. 

But, it is, after all, just a bike, and it does amazing things with a construction that has not changed all that much in years and years.

And, I do have to wonder how many smaller guys, if they had the chance, would like to build with this type of medium if they could, but it is out of reach for them financially AND at the level of engineering experience they have in their back pockets. A bit of sour grapes, perhaps.

Well, it will be interesting the see how this plays out. I sure doubt that it will go away. I am also sure there will be broken bikes and failures and corrections and successes until it gets figured out and becomes the norm for a lot of us. I am also quite sure there will always be a place for a simple, easy to understand, and amazingly capable thing as a bike frame made from a few expertly selected 'sticks' stuck together.

Choice is good.


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## DWF (Jan 12, 2004)

mtroy said:


> Interesting comments, and not quite what I expected (although I am not too surprised). I have to speculate here, cuz I do not know this for sure, but I doubt that there is a complete lack of engineering behind the formed tubes. Surely a manufacturer seeks to make their product unique and hydroforming does do that visually, but I think saying that it is all marketing driven does not stand up.
> 
> And one reason I say that is the existence of so many shaped forms in other types of engineered structures. They are not all round and butted.
> 
> ...


"Everything should be made as simple as possible, but no simpler." -- Einstein


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## Walt (Jan 23, 2004)

*I always thought...*

...that the hydroformed tubes were just intended to allow a really big fat downtube to interface well with a 1 1/8" head tube (or fat toptube to mate up with a skinnier seat tube, etc). I've ridden both traditional straight tube and hydroformed aluminum frames and can't say they ride any differently, so I always figured it was just a manufacturing trick to make things mate up more easily (cheaply).

Is there some other purpose?

_Walt


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## themanmonkey (Nov 1, 2005)

mtroy said:


> Interesting comments, and not quite what I expected (although I am not too surprised). I have to speculate here, cuz I do not know this for sure, but I doubt that there is a complete lack of engineering behind the formed tubes. Surely a manufacturer seeks to make their product unique and hydroforming does do that visually, but I think saying that it is all marketing driven does not stand up.


Why doesn't it stand up? You just said you are speculating what basis do you have for your speculation?

Sure there is some engineering, but we're taking bicycles here. They're not rockets or bridges or Formula-1, they're bikes. A 2-3% increase in stiffness and vibration absorption and 12 gram reduction in weight doesn't matter here. The key most people forget is we're always talking about bikes and the stakes are so low and gray areas so big little things like hydroformed tubing don't really matter. Go back and read what *DWF* has said repeatedly and it's sagely advice.

ADDED: What *Walt* said is the only real reason I can understand for using the tubing.


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## smdubovsky (Apr 27, 2007)

Hydroforming is not just for looks. Its used alot in the car industry on things like truck frames that are hidden from view. It can make stronger parts more cheaply.

Round tubes are ideal for SOME parts of bikes. Take a look at any FEA analysis and you'll realize that its not ideal for ALL parts. Stresses are not evenly distributed. Hydroforming is simply the next step beyond butting. Putting the material where is needs to be.

All that said: Swoop does sell and Im sure merketing does play some part. I personally like the look of the DT arching over the front wheel a little. I see it as a win/win. Not too many custom builders are doing aluminum bikes so I don't know that it matters to this crowd much.


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## mtroy (Jun 10, 2005)

themanmonkey said:


> Why doesn't it stand up? You just said you are speculating what basis do you have for your speculation?
> 
> Sure there is some engineering, but we're taking bicycles here. They're not rockets or bridges or Formula-1, they're bikes. A 2-3% increase in stiffness and vibration absorption and 12 gram reduction in weight doesn't matter here. The key most people forget is we're always talking about bikes and the stakes are so low and gray areas so big little things like hydroformed tubing don't really matter. Go back and read what *DWF* has said repeatedly and it's sagely advice.
> 
> ADDED: What *Walt* said is the only real reason I can understand for using the tubing.


OK, substitute WAG for speculate! I don't need a basis for WAGs.

If it is only 2-3% and 12 grams, numbers that I imagine you are just tossing out there as an example, then I guess it does not matter. Or maybe those are test results from a specific frame that was put through the rigors of testing. I don't have any numbers to suggest like you do.

If the stakes are that low and the gray areas that big, then there would be no need for the skill of a custom builder. It is all just tubes, right? But that is not the case.

I don't think I have forgotten it is just a bike...I have said that a couple of times. But I have ridden a couple of these bikes and they are pretty good. I really don't have a dog in the fight, just seeing what some of the opinions might be.


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## mtroy (Jun 10, 2005)

smdubovsky said:


> Hydroforming is not just for looks. Its used alot in the car industry on things like truck frames that are hidden from view. It can make stronger parts more cheaply.
> 
> Round tubes are ideal for SOME parts of bikes. Take a look at any FEA analysis and you'll realize that its not ideal for ALL parts. Stresses are not evenly distributed. Hydroforming is simply the next step beyond butting. Putting the material where is needs to be.
> 
> All that said: Swoop does sell and Im sure merketing does play some part. I personally like the look of the DT arching over the front wheel a little. I see it as a win/win. Not too many custom builders are doing aluminum bikes so I don't know that it matters to this crowd much.


Ah, the voice of reason and balance, I do believe I hear. Yeah, I guess this is a steel crowd, but I figured that it was a better place then any other forum. At least you guys actually make things, not just inner-web engineering.


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## AZ (Apr 14, 2009)

themanmonkey said:


> Why doesn't it stand up? You just said you are speculating what basis do you have for your speculation?
> 
> Sure there is some engineering, but we're taking bicycles here. They're not rockets or bridges or Formula-1, they're bikes. A 2-3% increase in stiffness and vibration absorption and 12 gram reduction in weight doesn't matter here. The key most people forget is we're always talking about bikes and the stakes are so low and gray areas so big little things like hydroformed tubing don't really matter. Go back and read what *DWF* has said repeatedly and it's sagely advice.
> 
> ADDED: What *Walt* said is the only real reason I can understand for using the tubing.


Liability issues make it more than low stakes , just saying you know .


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## Walt (Jan 23, 2004)

*A few more thoughts*

First, a bit of context: the variety of good quality mountain bikes (both mass produced and custom) available now is astounding. There are an awful lot of good bikes out there both with and without hydroformed tubes.

But putting this in the context of global trade and mass manufacturing in general over the last decade or so, my BS detector goes off quickly when I hear crazy engineering claims about every new technology, *especially* when that technology happens to make it easier or cheaper to mass produce whatever product. Does that mean the technology is bad? Of course not! Cheaper/easier are good things, as long as you're not sacrificing quality (let's not get into whether or not buying everything we own from China is a good idea for now, since that kind of thread just devolves into name-calling in a hurry).

WRT hydroformed tubes specifically, I tend to see them on bikes where I *don't* see much effort made to really tune/engineer the different stock sizes for different riders (ie, same diameter tubes on every size from XS to XL, identical chainstay lengths and BB heights on every size, etc, etc). This generally leads me to believe that manufacturing costs are the driving force behind most of this kind of innovation, not improvements in riding characteristics.

I could of course be wrong. But Occam's Razor says that the best explanation here is just keeping costs down. Of course, that makes pretty crappy marketing copy ("just as good as last year, but 20% cheaper for us to make!"), so if you can make some tweaks to make the frame do a tiny bit better on a test rig, you're a lot better off using that as a selling point, even if the end consumer will never be able to tell.

So I'm not saying hydroformed tubes are bad. I'm just saying they're probably more beneficial to the manufacturer's bottom line than the rider's enjoyment. Just IMO, as always.

-Walt



mtroy said:


> OK, substitute WAG for speculate! I don't need a basis for WAGs.
> 
> If it is only 2-3% and 12 grams, numbers that I imagine you are just tossing out there as an example, then I guess it does not matter. Or maybe those are test results from a specific frame that was put through the rigors of testing. I don't have any numbers to suggest like you do.
> 
> ...


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## rustola (Jan 15, 2008)

Walt said:


> just as good as last year, but 20% cheaper for us to make!


love it!


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## jay_ntwr (Feb 15, 2008)

smdubovsky said:


> Hydroforming is simply the next step beyond butting. Putting the material where is needs to be.


Agreed, that really is the primary benefit and about the best way to describe it.

Good solid modeling tools allow designers to come up with very complex shapes fairly easily AND test them in FEA for not only strength but for deflections. As all of this stuff has become very easy to use, very available and the talent to operate it is abundant, you'd better believe that it's going to get used more and more in bike design--or any other.

I've got a hydro formed FS 29er and I like the bike. It's really nice, stiff, light, etc. and not too expensive all things considered.

Hydroforming makes sense when talking about a light bike that is strong in the right places. That said, sometimes form is more important than function.

I'm not in the camp that Hydroforming is "cheap". It required very expensive tooling and the process isn't cheap or easy. What you do see now though is a (hydroformed) model being on the market with almost no change for a lot longer. So maybe the cost does come down in the end, but it's not cheap. That's the biggest barrier for custom builders and I don't think we'll see hydroforming being something that custom folks ever do.

I'm interested in form though. The round, butted tube is efficient enough for me and what I'm doing. Couple that with building the tube selection to be chosen around the rider size, style, etc. and there probably isn't a significant advantage to off the shelf hydroformed tubing built for the fattest guy they think can ride a bike. That said, in fantasy land, if a custom builder could have free tooling and design custom hydroformed tubes, then a stronger, stiffer, lighter frame that was generally more compliant would be possible. It would just cost hundreds of thousands (if not more) to produce. But the potential is there to make a better bike, technically. Practically, no way.

But then again, I can't even bend a seatstay yet.


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## mtroy (Jun 10, 2005)

Walt said:


> First, a bit of context: the variety of good quality mountain bikes (both mass produced and custom) available now is astounding. There are an awful lot of good bikes out there both with and without hydroformed tubes.
> 
> But putting this in the context of global trade and mass manufacturing in general over the last decade or so, my BS detector goes off quickly when I hear crazy engineering claims about every new technology, *especially* when that technology happens to make it easier or cheaper to mass produce whatever product. Does that mean the technology is bad? Of course not! Cheaper/easier are good things, as long as you're not sacrificing quality (let's not get into whether or not buying everything we own from China is a good idea for now, since that kind of thread just devolves into name-calling in a hurry).
> 
> ...


Excellent. Thanks for your input!


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## mtroy (Jun 10, 2005)

jay_ntwr said:


> Agreed, that really is the primary benefit and about the best way to describe it.
> 
> Good solid modeling tools allow designers to come up with very complex shapes fairly easily AND test them in FEA for not only strength but for deflections. As all of this stuff has become very easy to use, very available and the talent to operate it is abundant, you'd better believe that it's going to get used more and more in bike design--or any other.
> 
> ...


I think you are very close to my thoughts as well. I see hydroforming a tube into a shape that the typical round tube could never match in its ability to make it just what it needs to be in just that place in the frame. A round tube is likely to be a compromise as far as I can see, although that compromise may or may not be insignificant. If all it does it make it cheaper to manufacture, but I still get a good bike, that is OK with me. I think they can look dead sexy in those shaped tubes.

That said, I love the look of my steel Jabberwocky mostly because of the classic shape, small steel tubes, and simple look. I like Walt's stuff for that reason as well.

I am not into the manufacturing, but I have to imagine the cost to design, tool up and test is pretty darn high.


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## themanmonkey (Nov 1, 2005)

mtroy said:


> OK, substitute WAG for speculate! I don't need a basis for WAGs.
> 
> If it is only 2-3% and 12 grams, numbers that I imagine you are just tossing out there as an example, then I guess it does not matter. Or maybe those are test results from a specific frame that was put through the rigors of testing. I don't have any numbers to suggest like you do.
> 
> If the stakes are that low and the gray areas that big, then there would be no need for the skill of a custom builder. It is all just tubes, right? But that is not the case.


Ahhh, a WAG I accept.

The numbers I have are from talking to industry folks, remember this is my day job. The couple % and few grams that hydroforming "improves" things is round numbers from discussions with designers and reps with BIG companies. Hydroforming is just one of the many things tubing and bicycle companies do to change the strength and weight of bikes.

What a custom builder gives you isn't better quality or a lighter bike. There are welders in China as good if not better than folks in the states. with custom builders you get just that 'custom' which is something the big boys can't touch. Trek and Cannondale recently tried and failed. Before steel started making its comeback you really had to go to a custom builder for that too in most cases.

As to *AZ.MTNS* that warranty isn't low stakes. Bikes are generally over-built and warranty isn't really an issue that hydroforming's small "benefits" will help with. Good sound design and engineering is where things need to start and then good QC is the second most important step most of the big players pass on.

Having been in this game for a long time I can say the there are fewer warranty issues today than in the past. When crazy lightweight (any material) is popular you'll see a lot of breakage and then companies beef stuff up. If hydroforming is difference between your product braking and not you have a poorly designed product.

All that said. I work with and ride hydroformed tubing bikes almost everyday, mostly Kona and Marin. This where all the above information comes from. Raise your hand if this is true for you too. The internet is chock full of armchair engineers that speak words that are mostly WAG or founded on internet rumor of other armchair engineers. For those of us that this stuff is our livelyhood you can see how this my be frustrating. So sorry if I come across as a jerk.


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## mtroy (Jun 10, 2005)

themanmonkey said:


> Ahhh, a WAG I accept.
> 
> The numbers I have are from talking to industry folks, remember this is my day job. The couple % and few grams that hydroforming "improves" things is round numbers from discussions with designers and reps with BIG companies. Hydroforming is just one of the many things tubing and bicycle companies do to change the strength and weight of bikes.
> 
> ...


Not a jerk at all. Good info. And very interesting numbers. I do find it interesting that there is so little performance difference between the two ways to do things. The hard thing to do, as an end user (the rider), is to directly correlate performance increases to a particular feature alone, like a specially shaped tube. The bike's performance is so much a combo of all the parts and design. I really like the looks of both of these, one a pressed, folded, and spindled hydro-beauty, and one a traditional yet innovative frame. Could I tell the difference just from the hydro stuff? I dunno, but I like the choices.


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## scottzg (Sep 27, 2006)

I don't see the point, other than marketing. Hydroforming is another illustration of the difference between precision and accuracy. Sure, you can change the way the frame rides by hydroforming, but the major manufacturer is still trying to make 4 sizes fit every rider. It doesn't matter how close they can get to the perfect frame for an archetype rider that probably isn't the end user.


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## mtroy (Jun 10, 2005)

scottzg said:


> I don't see the point, other than marketing. Hydroforming is another illustration of the difference between precision and accuracy. Sure, you can change the way the frame rides by hydroforming, but the major manufacturer is still trying to make 4 sizes fit every rider. What difference how close they can get to the perfect frame for an archetype rider that probably isn't the end user?


I don't get the precision/accuracy inference:skep:

But the sizing thing is not limited to the big guys. Even the small guys do that as well, the true custom builder being the exception.

Besides, people do not typically vary so much in size and weight within a overall height that stem changes, bars, saddles position, yada, yada, do not do a decent job of getting them there. For the truly odd shaped or very particular, then they can pony up the cash for a custom frame or shop for a bike maker that builds more to their needs.

As a bike maker, trying to slice that bike sizing pie into tiny, individual pieces would be too costly for them and confusing for the bike shop and the customer most likely.

But I agree that things like crank length, CS length, HT angle often are not adjusted between sizes, although I was looking at a sizing chart from the Big S that did show some variation from S to LG in some of those areas. Kinda surprised me.


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## scottzg (Sep 27, 2006)

mtroy said:


> I don't get the precision/accuracy inference:skep:
> 
> But the sizing thing is not limited to the big guys. Even the small guys do that as well, the true custom builder being the exception.
> 
> ...


Hydroforming allows the manufacturer to tune the ride to a degree that its meaningless, because they don't know who they're designing for. Besides, they're using the same swoopy tubes for every size- bumping up the tube diameter depending on the size would do more for the ride than making it curvy.

Or maybe i'm biased because at a not-exceptional 6'3 225lbs, I've found that the production bikes that fit me, handle well, and hold up under my use are few and far between. It sucks.


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## BadHabit (Jan 12, 2004)

jay_ntwr said:


> I'm not in the camp that Hydroforming is "cheap". It required very expensive tooling and the process isn't cheap or easy....That's the biggest barrier for custom builders and I don't think we'll see hydroforming being something that custom folks ever do.


In this perhaps an insight into negative views.


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## mtroy (Jun 10, 2005)

BadHabit said:


> In this perhaps an insight into negative views.


I have been thinking that as well, but regardless it has been very interesting reading the responses. I know it has made me think twice about what I thought was a superior approach in many ways.

Thanks all.


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## Thylacine (Feb 29, 2004)

70% marketing, 20% improved manufacturability, 10% improved warranty returns because of greater weld surface area.

Sound about right?


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## BadHabit (Jan 12, 2004)

*"Oh, the gussets..."*



Thylacine said:


> Sound about right?


No one is thinking of the poor gussets.


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## ted wojcik (Mar 12, 2006)

Round tubes, square tubes, oval tubes, Ti tubes, Al tubes, carbon tubes, monocoque, hydro formed, stamped, cast, welded, or bonded, they are all different, but is any one clearly superior in every condition? We know that is simply not the case. Be honest, are we drawn to any of these materials or constructions based on cosmetics? Absolutely. Styles change as do frame appearances. Whatever frame type you find superior, I can find someone who hates it and visa versa. Ride quality is comparative and the standard of comparison always goes back to a round tube steel frame. Does that make it superior? It depends on your definition of superior. Is it lighter, stiffer, smoother? Compared to what? What is important is fit and handling. If it doesn't fit or handle well, you're not going to like it. If it does, you will notice the comfort for long rides and a confidence in handling. Here is something you can measure and make a definitive comparison. If you require or desire a bike with a certain fit or handling characteristic and will benefit from a custom build, this will narrow construction type quite a bit. If you are into the trends in style, it will surly change in a year or two anyway and you will always be chasing the latest and greatest.


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## SuspectDevice (Apr 12, 2004)

Thylacine said:


> 70% marketing, 20% improved manufacturability, 10% improved warranty returns because of greater weld surface area.
> 
> Sound about right?


Yes sir. And once again, this can all be done with coldworking... by the builder themselves even!


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## Tayancycles (Mar 6, 2006)

I think it is the design aspect that needs to be rethink. When I say design I mean understanding the context and the riders' need and use the right material and tubing styles to meet the ride characteristics for the specific need. .


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## Schmitty (Sep 7, 2008)

If you can't get it done with round, you can't get it done. You can ride J Lo for all I care, if you ain't got fitness/skills it doesn't matter.


The white elephant in the room, at least as far as steel builders go, is lack of hydo formed tubes anyways, so I think certain (nagative) views are gotten by working backwards from the fact that some builders are sol... pretty much stuck with whatever comes down the pipe (!), which for the most part, is round, and that's fine by me.

Geometry, fit, build, trump all.

-Schmitty-


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## SC RockLobster (Jul 22, 2007)

Schmitty said:


> You can ride J Lo for all I care,
> 
> -Schmitty-


 HUMM J LO, would that be considered round or hydroformed ?:thumbsup:


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## shiggy (Dec 19, 1998)

SC RockLobster said:


> HUMM J LO, would that be considered round or hydroformed ?:thumbsup:


Bioformed


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## Velorangutan (Aug 28, 2012)

[digging up old thready] I've recently been searching for information on this subject. Thanks to all for the insights from 12 years ago! Everything I had gathered before finding this thread leads me to believe the same thing most of you were thinking. In respect to Ti, I keep finding statements about round tubes being the stiffest and strongest. THis is coming from outside the bicycle industry. It's starting to look like hydoforming is less about strength/stiffness and more about shapes and design layout. And marketing.


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## compositepro (Jun 21, 2007)

Velorangutan said:


> [digging up old thready] I've recently been searching for information on this subject. Thanks to all for the insights from 12 years ago! Everything I had gathered before finding this thread leads me to believe the same thing most of you were thinking. In respect to Ti, I keep finding statements about round tubes being the stiffest and strongest. THis is coming from outside the bicycle industry. It's starting to look like hydoforming is less about strength/stiffness and more about shapes and design layout. And marketing.


Hydro formed titanium?


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## Velorangutan (Aug 28, 2012)

compositepro said:


> Hydro formed titanium?


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## compositepro (Jun 21, 2007)

Velorangutan said:


> View attachment 1965818


thats nice innit


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