Atlantis or Hunq - what's the real difference?

[Mark Reimer]

I've had my Atlantis for about half a year now and am loving it. I usually run it with 2.1 WTB Nano's, and feel like I could probably get 2.2's in there actually. Most of the riding I've been doing is on trails, back roads, across fields, over the snow, etc. AKA, not pavement. I don't have any complaints save one - I tend to hit the pedals on the ground somewhat often when I get into bumpy, rocky, or off-camber territory. Not a huge deal, some strategic pedalling takes care of that. However, a few times I've pondered if I'd be better of with a Hunq. But after looking at the geo charts, it looks like the BB-drop is actually identical. Quite a bit of the geo is similar actually. So it makes me wonder, what's really the difference between them? 

I know the tire clearance has changed over time. Some maxed out at 2.1 I think. Newer Hunq's can handle 2.3's if I'm not mistaken. If we ignore the tire clearance for the moment, is there something I'm missing? Would an Atlantis with Bullmoose bars = Hunq and a Hunq with Noodles = Atlantis? 

This is mostly out of curiosity. I'm over the moon with my Atlantis and don't hesitate to load it down and take it over the roughest terrain. The frame is so heavy duty I can't imagine it being incapable of handling anything the Hunq could.

[Goshen Peter]

Isnt there a tubing difference? Also not point out the obvious but with the extra diagatube the hunq has to be stiffer, right?

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[Mark Reimer]

I'm curious if it's stiffer. My Atlantis has such thick tubing I can't feel it flex at all, even loaded. I feel flex in the quill stem and bars, but not the frame. 

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[Goshen Peter]

Hey I rode a bombadil, it was nice and stiff for a heavy dude. Never felt flex even with kiddo on it.

[drew beckmeyer]

as a hunq owner, ive wondered this from the opposite (yet 100% satisfied) side.  my impression is that there are a couple geometry tweaks and slightly thicker tubing? ive also wondered what makes the atlantis frames slightly more expensive. 

[Garth]

First, what you can't see and what is not published, the tube selection , as well as the obvious extra tube :-)

Also, the TT and front-center is longer on the Hunq. , as well as longer chaninstays and more fork rake . 

[Chris Lampe 2]

All of these numbers and facts are being pulled from my memory of reading about Rivendells for several years so they may not be 100% accurate but they are probably close.

I remember the Atlantis having .9/.6./.9 tubing, which isn't really that stout.  I don't know if I've seen the tubing stats for the Hunq but I'm sure they are thicker and may be the same as the Bombadil, which I've read was 1.x straight gauge tubing.  

I communicated with Grant several years ago when I weighed 360 and the Hunq/Bomba were the only Riv's he would recommend for me.  He would not recommend the Atlantis so there is definately a tubing difference.  

[drew beckmeyer]

really? straight gauge?

[Goshen Peter]

That's what I was told re bombadil tubing too. 1 straight gauge.

On Feb 12, 2015 1:24 AM, "drew beckmeyer" <drewbe...@gmail.com> wrote:

really? straight gauge?

[Chris Lampe 2]

I think that may be one of the misconceptions about Rivendells and Grant has even made comments that support this.  Rivendell's use expensive tube sets because who would buy a $2000 frame knowing it had plain ole' 4130 cro-mo?  People expect fancy steel in a frame that expensive.  However, since bikes like the Bombadil and Hunaqapillar may have 1+mm tubing (straight or butted...who knows?) and the Atlantis has 9/6/9 tubes, there may not be that much benefit to the expensive tubes.  My understanding is that the benefit of expensive tubes is high quality steel that allows the builder to use less of it and produce a higher performance bike.  The heavier Riv's don't seem to be designed to take advantage of this.  The Roadeo and maybe the AHH may be a different story and they may benefit tremendously from better tubing.  

There's probably more to the story when you get into the fine details of all parts of the frame but overall, I think the above is accurate.  

On Thursday, February 12, 2015 at 12:24:50 AM UTC-6, drew beckmeyer wrote:

really? straight gauge?

[Surlyprof]

This from the Hillborne catalog:

"Silver Tubes. They look normal from the outside, but

Silver tubes are our own design and are better for it.

Rather than using industry-standard double-butted tubing

picked stock from a catalogue, we shifted the wall

thickness around to better address the stresses. long

story short, we have more metal where it matters and

less where it doesn’t. There is not a better-designed

tubeset available, and it’s ours (and yours) alone."

Sounds similar to the way Thomson seatposts have a round outer cross section and an elliptical interior section leaving metal where strength is needed and less where it is not.

John

[Chris Chen]

When he was repairing my 57 AHH, my friend remarked that the tubing was surprisingly light, maybe 8 5 8 or something like that. So yeah, there be differences!

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[drew beckmeyer]

i guess what im wondering is, if the hilsen has proprietary tubes, the atlantis has thick yet standard dbl butted tubes and the hunq has straight gauge, why are they all roughly the same price? obviously, tubing is far from the most expensive part of building a bike, but i assume that the labor intensiveness and lug-workmanship etc. is about the same on those 3 models.  maybe not though... ive never built a bike frame

[Mark Reimer]

Maybe quantity? complexity of paint and lugs? I think the tubing would be very marginal in the total scheme of things.

Visit Nova Cycle's website. You can see the pricing of a ton of different tube-sets and lugs. The pricing is all fairly comparable. 

On Thu, Feb 12, 2015 at 12:22 PM, drew beckmeyer <drewbe...@gmail.com> wrote:

i guess what im wondering is, if the hilsen has proprietary tubes, the atlantis has thick yet standard dbl butted tubes and the hunq has straight gauge, why are they all roughly the same price? obviously, tubing is far from the most expensive part of building a bike, but i assume that the labor intensiveness and lug-workmanship etc. is about the same on those 3 models.  maybe not though... ive never built a bike frame

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[Clayton]

I met an ex-employee of Rivendell, and we talked a bit. I bought my Atlantis in '98 or so. He said, "You have one of the good ones. The newer Atlantis is made from heavier, cheaper tube sets." I love my Atlantis. Would I love a new one as much? Probably. Would I buy a new Atlantis? Maybe. 

[Mark Reimer]

Meh. I'm not sure when my Atlantis is from, but I'm thinking early 2000's or so. If it's heavier than others, I'd never know with all the crap I've got bolted/strapped/hanging off of it. 

I am, however, jealous of the Atlantis' (Atlanti?) with the fancier lugs and mid-fork braze-ons. Very jealous. 

On Thu, Feb 12, 2015 at 12:28 PM, 'Clayton' via RBW Owners Bunch <rbw-owne...@googlegroups.com> wrote:

I met an ex-employee of Rivendell, and we talked a bit. I bought my Atlantis in '98 or so. He said, "You have one of the good ones. The newer Atlantis is made from heavier, cheaper tube sets." I love my Atlantis. Would I love a new one as much? Probably. Would I buy a new Atlantis? Maybe. 

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[Chris Lampe 2]

I have a memory of reading some specs on the AHH and at most, it was 8/5/8.  It was something like Roadeo = 7/4/7, AHH = 8/5/8, Atlantis = 9/6/9.  I don't remember a mention of butted tubes but I suspect the Roadeo and AHH have them and maybe the Atlantis.  

[Scott Wolfe]

hi, mark.

i got a chance to ride both bikes before making my choice on what to buy. i rode a 2001 atlantis with 26 inch wheels in a 54/55 and the first generation hunq in 58 that was too big. the changes to the 2nd generation hunq won me over as did the chance to run 700c/29'er tires in my size, which turned out to be 54 in the hunq. i didn't shop on price but on function.

weight: i didn't notice a difference between the two bikes because both were ridden with racks, bags, etc. that said, when my hunq showed up out of the box i was surprised at how light it was. i still am now that it's built and rolling.

performance and fit: i knew what kind of bars, tires and fit i was looking to build around when i made my choice and ordered. i wanted to be able to run a very wide tire on the front and something that could be run at low psi with a big'r footprint on the rear. the hunq did that for me. i also wanted a slightly sloping top tube as i knew the upright albatross bars i was going to run i didn't to have too much stem rise to keep the front end responsive for trail riding with a load. again, these were my personal preferences based on past riding and future riding. oh, for reference i run wtb 2.5 weirwolf on the front with plenty of clearance and wtb nano raptor 2.1 on the rear. i had a 2.3 on there, but it was overkill. it had plenty of clearance, though.

cheers.

scott
bend, or

[Aaron Young]

I recently had a discussion with an experienced frame builder and it came up that tubing diameter has a bigger effect than the thickness or thinness of the tubes; at least with common wall thicknesses.  Apparently there are online calculators that show flex characteristics of a tube and this is where that idea can be verified. 

I'm certain the outside diameter of the Atlantis tubes are the same as always.  So wether its tubes are a bit thinner/thicker is probably not that important.  

We didn't discuss the effect of butted vs straight gauge so I can't comment on that.  Based on how folks seem to love even the straight gauge Rivs, my guess is it doesn't have a very strong impact on the overall experience. 

Aaron Young

The Dalles, OR

[Joe Bernard]

The most noticeable difference I can see is that the Atlantis has fancier lugs. If it's also marginally lighter and I didn't need the extra stoutness, I would certainly pay and extra 300 for those qualities.

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[Joe Broach]

On Thu, Feb 12, 2015 at 4:07 PM, Aaron Young <1ce...@gmail.com> wrote:

I recently had a discussion with an experienced frame builder and it came up that tubing diameter has a bigger effect than the thickness or thinness of the tubes; at least with common wall thicknesses.  Apparently there are online calculators that show flex characteristics of a tube and this is where that idea can be verified. 

I'm certain the outside diameter of the Atlantis tubes are the same as always.  So wether its tubes are a bit thinner/thicker is probably not that important.  

We didn't discuss the effect of butted vs straight gauge so I can't comment on that.  Based on how folks seem to love even the straight gauge Rivs, my guess is it doesn't have a very strong impact on the overall experience. 

Aaron Young

​In the range of common bicycle tubing, the rule of thumb is one step in diameter changes deflection about the same as two steps in thickness. So, a 25.4 (non-OS) top tube in 9-6-9 will flex about the same as a 28.6 (OS) top tube in 7-4-7. The OS tube will be a little lighter, but the non-OS tube will be tougher (if the steels are similar). Of course, then there's number of top tubes to consider!

Best,

joe broach

portland, or

[Goshen Peter]

Ok so a totally not off topic question, what tubing does the Cheviot have. More Sam or homer? Anyone ride all 3?

[Mike Schiller]

I recall reading that the Hunq used Kaisei heat treated tubing in 9-6-9 OS.  This tubing has a higher tensile strength than Ox Plat which is what the  Atlantis uses.  Which only means it's more resistant to denting and not any stiffer.  I also thought that the Hunq's were made in Taiwan and not at Waterford like the Atlantis.  

~mike

Carlsbad Ca.

[drew beckmeyer]

i believe that's the same info that was floating around in the back of my head as well, Mike.  but now im wondering if i gained it from a reputable source. pretty sure about the kaisei heat treated part. not so sure about the specs. and hunqapillars moved to waterford a while back. i guess it doesnt really matter. i love my bike so hard and not much is gonna change that, but i am kinda curious to know everything about it. 

[Chris Lampe 2]

​In the range of common bicycle tubing, the rule of thumb is one step in diameter changes deflection about the same as two steps in thickness. So, a 25.4 (non-OS) top tube in 9-6-9 will flex about the same as a 28.6 (OS) top tube in 7-4-7. The OS tube will be a little lighter, but the non-OS tube will be tougher (if the steels are similar). Of course, then there's number of top tubes to consider!

Best,

joe broach

portland, or

 

Thanks for posting this fascinating tid-bit of information.  Frame design has become a particular interest of mine and I enjoy learning things like this.  

 

[Leslie]

On Wednesday, February 11, 2015 at 7:26:43 PM UTC-5, Chris Lampe 2 wrote:

All of these numbers and facts are being pulled from my memory of reading about Rivendells for several years so they may not be 100% accurate but they are probably close.

I remember the Atlantis having .9/.6./.9 tubing, which isn't really that stout.  I don't know if I've seen the tubing stats for the Hunq but I'm sure they are thicker and may be the same as the Bombadil, which I've read was 1.x straight gauge tubing.  

I communicated with Grant several years ago when I weighed 360 and the Hunq/Bomba were the only Riv's he would recommend for me.  He would not recommend the Atlantis so there is definately a tubing difference.  

FWIW:  at some point, I ended up in a bike-camping discussion that was related to tubing, and ended up, I asked Riv about my Bombadil specifically (one of the diaga-tubed Bomba's).   Their reply was:


"The seat tube is a straight gauge OX platinum .8mm tube that is opened up to accept a 26.8 post at the top.  The top tube and down tube are also .8 straight gauge OX Platinum tubes.  We opted for a stouter than normal seat tube so that the tube would be thicker at the mid seat brazing point.   You've got plenty of steel there!"
 
And in another email, they said the diagonal was the same as the top-tube; so, at least for my Bomba, the top, diagonal, and downtube are all straight 8, and the seat tube is also a .8, save for the upper end, to accept the seatpost. 

I think, w/ the diagonal, there wasn't any need to go larger than the straight 8. 


-L

[Chris Lampe 2]

Very interesting!   Thanks for adding specific details that came from RBW.  

[Braxton Colagross]

Hunqapillar frames are made by Waterford. The $300 savings comes from the fork being made in Taiwan. 

[Tim]

Speaking of Hunqa tubing: 2 1/2 years ago I bought a 58cm kidney and dolphin Hunqa from Riv. This was after they changed the color to green, so I felt lucky to pick it up. Well, the seat tube will not fit the 26.8 seat post like it should. I had to find a cheapy 26.2 to fit which means I can't use a Nitto because they don't make that size. I exchanged emails with Grant and Keven about it. After giving Keven the serial number, he told me that it was a Taiwanese/Japanese Toyo bike. No one can really figure out why the seat post doesn't fit. There are no burrs inside the tube and it appears to be round, not oversized. It's not a huge deal to me except for having to use the non-Nitto post. It's been suggested to ream the tube or turn down a 26.8 post. Maybe the seat tube didn't get "opened up to accept a 26.8 post"? Thoughts?

[Mike Schiller]

the original Hunq frame was made in Taiwan and the fork made by Toyo in Japan. 

~mike

[Shoji Takahashi]

My second-hand red and gray 48cm Hunqapillar was made at Waterford. The original intent was to have them all made in Taiwan (+ Toyo), but apparently a long wait made Riv reconsider and at least some were made at Waterford. (This is what I was told by the original purchaser.)

BTW: the most important difference between the Atlantis and the Hunqapillar is the head badge. 

Shoji

[brianweee]

From looking at the geo charts it looks like the Hunqapillar is built with more off road downhill capabilities. With 3-4cm longer in the top tubes, slacker HT angle, 1-2 cm longer chain stays, it will have a longer wheel base and feel more stable in downhill descents. 

[drew beckmeyer]

the angles make sense. i did a bit of digging and the hillborne and atlantis have the same tube dimensions, or at least that was true in 2010. i didnt think the sams were quite that stout, but that's cool.  still curious about the hunq tubing. ive heard ox and kaisei. kaisei was named in the very first iterations of the hunqapillar. it was also listed as being .1 thicker than atlantis tubing. im not sure if that means proportionally, or straight gauge as has been mentioned here....likely all of this information has changed somewhat since it's original writing, right?

also, im curious about Tim's seat tube issue since the more recent hunqs take a 27.2 seat post and it seems like his was meant to fit a 26.8, but couldnt even do that.

[doc]

It seems a lot of Atlantis owners get their frames painted/re-painted a nice mix of attractive colors, but I don't know of one Hunq painted Seafoam Green.

[Jim Bronson]

Custom paint is expensive...I would be more likely to take the Rivendell standard colors if I was buying a stock model.  IIRC, Grant has written somewhere that you can get frames painted any color you want...for $500 extra.

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Keep the metal side up and the rubber side down!

[Leslie]

I think, it was that their fancy paint is a $500 paint job, but that to have a bike painted in a non-standard color is $300...
https://www.rivbike.com/kb_results.asp?ID=66 
(At least, if the prices haven't shifted....)

-L

[Leslie]

I was going to say that it might be considered a bit 'weird' to borrow the Atlantis color for a Hunq, since it's not an Atlantis, but. I did get my Bombadil in Rambouillet orange, so, I really don't have room to talk....    I'm sure you can get a different bike in a whichever color.... there's that Betty Foy that was painted to match an Atlantis for a pair of his/hers bikes, so it's not impossible....  

[drew beckmeyer]

well i just went ahead and asked, since i was asking other questions anyway. 

via Will

"Atlantis and Hunqapillar are both straight gauge (not a bad thing!) os x platinum .8mm in the main triangle. The fork is tougher on the Hunqa and the chainstays are thicker... The geometries are different, but the tubing is basically the same. Oh and Hunq forks are made in Taiwan, the rest is made by Waterford, which accounts for the price difference between the two models."

[Leslie]

Interesting!  So the Bomba, Hunq, and Atlantis are all three straight 8 OX Plat in the main triangle....   makes sense, but, there it is......

-L

[clayton bailey]

Straight gauge is usually used in lugged construction, as the lugs provide the "butting". 

Clayton (Bend)

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[Jim M.]

On Wednesday, March 11, 2015 at 10:04:45 AM UTC-7, Leslie wrote:

Interesting!  So the Bomba, Hunq, and Atlantis are all three straight 8 OX Plat in the main triangle....   makes sense, but, there it is......

-L

I don't know about the Bomba production run, but the prototypes were not straight gauge. The prototypes had 1.2/0.9 main down and seat tubes.

http://www.cyclofiend.com/Images/rbw/rr39_pg45.jpg

jim m

wc ca 

[Garth]

  Yes , that's the photo I recall Jim :)    It was always my understanding of the Bombadil frames was only the second TT was straight gauge , the rest were butted . 

[Justin August]

It sounds like it's very important to add an "At this time..." to all replies you get regarding tubing, etc from the folks at Riv. I remember as each of those new-er models was introduced that the changes were more than just geometry and chain stays. I think Riv does running changes within their production bikes to probably benefit us (consumers and riders) and them (producers and business). I rest assured that they wouldn't make a drastic change that altered the ride characteristics without airing it out.

-J

[Leslie]

Good point:  I was asking about *my* Bomba, and the reply was about mine, being straight-8 OX Plat.   And, mine is one of the later diagonal-tube Bombadils, not the earlier top-tube... the later ones also had a different crown than earlier ones, a new lug was introdiced, etc.   

SO, Maybe not all Atlanti have been, and not the early Bombas then either;   but 'current' built Hunqs and Atlanti are.... ?     (Maybe, but always subject to revision.....)

[Joe Broach]

On Wed, Mar 11, 2015 at 10:14 AM, 'clayton bailey' via RBW Owners Bunch <rbw-owne...@googlegroups.com> wrote:

Straight gauge is usually used in lugged construction, as the lugs provide the "butting". 

 

​Clayton, that statement seems a bit broad. I'd say the great majority of mid to high end lugged bikes have used butted tubing since way back, and Reynolds for one was pushing butted tubing at the turn of last century (as The Patent Butted Tube Company Limited). 

As far as I know, all Rivs used butted tubing until pretty recently. Lugs don't change the fact that torching the tube ends weakens them. I'll be curious to hear Riv's thinking on the change; hopefully in a new Reader! I'm guessing the new super steels make straight 8 more attractive. 

Best,

joe broach

pdx or

[Benz, Sunnyvale, CA]

That was an interesting comment from Will. I guess Sheldon Brown had outdated data:

Top Tube: True Temper .9-.6-.9, 28.6 (1-1/8")

Down Tube: True Temper Heat Treated .9-.6-.9, 31.8 (1-1.4")

Seat Tube: True Temper .9-.6 Heat Treated

Head Tube: True Temper .9

Seat Stays: True Temper 16 mm diameter x .8 mm thickness

Chain Stays: Starlight Heat Treated

Fork Blades: True Temper 1.1mm tapering to .6 mm

While I can see tubing substitution for more readily available ones, I find it strange that Riv will do a complete substitution of 969 tubing for straight gauge 0.8 mm in the main triangle. If that is acceptable, why didn't they do it from day 1?

[Leslie]

It does say "subject to change without notice" on those;  and we know they changed from Toyo to W'ford anyway....

FWIW...

As far as to why, I'll leave it to Grant to improve, not hurt, the design...    not that earlier would be 'inferior', but, over time, he's increased clearances on bikes, and tweaked them where needed to improve...

[Mike Schiller]

I would be shocked if they are really straight gauge tubing.  That would add unnecessary weight without benefit and totally change the riding characteristics. He has to be kidding!

~mike

Carlsbad Ca. 

[cyclotourist]

I've got a feeling the butting is all external...

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Cheers,
David

Member, Supreme Council of Cyberspace

"it isn't a contest. Just enjoy the ride." - Seth Vidal

[Leslie]

On Monday, March 16, 2015 at 10:19:21 PM UTC-4, Mike Schiller wrote:

I would be shocked if they are really straight gauge tubing.  That would add unnecessary weight without benefit and totally change the riding characteristics. He has to be kidding!

Why?     They told me straight 8, they told Drew that.....  I don't think they'd 'kid' about that, without being clear that they were kidding.....

Thing is, a  9/6/9 vs a straight 8, I think the weight difference would be negligible...  ???

[drew beckmeyer]

agreed. those are the current specs and i think the weight difference is probably minimal as well. what i'm more curious about is what the benefit of straight 8 vs 9/6/9 is. 

[John]

Would the straight tubing be stronger if you're going to add the diagonal tubing?

John

[drew beckmeyer]

im thinking it helps with stiffness under weight and dent resistance?  it would be interesting to hear the impetus or thought process behind the change. 

[Mike Schiller]

 The difference is about 7 oz for a 60 cm bike ( the .8 mm straight tube weighs more). But the bike will also be stiffer riding as a butted tube is more flexible. But since the diameter is smaller the increase in stiffness is less than similar diameter tubes.

~mike

[Joe Broach]

Regarding butted tubing, here's an interesting old pre-Blug blog post I saved long ago. Not sure if it exists still (it does!). Some earlier thoughts from Riv/Grant on straight gauge tubing.

Best,

joe broach

pdx or

The T:T Faqtor?

March 23, 2010

It’s the Tube-to-Tire Ratio Factor.

Friend Ted wrote a couple of days ago and as part of a long email that included family stuff and a video, he also out of the blue said something like, “fat tires and skinny frame tubes look way better than skinny tire and fat frame tubes.” 
I’d already been working on that exact topic, and it was reaffirming to hear Ted say it right there out of the blue. I wonder how many other people have thought the same thing.

The early mountain bikes were great, widespread examples, but it doesn’t have to be that extreme to look good. (A current Atlantis-Bomba-Hunqa with fatties is the same). 

There’s no formula, so I’ll make it up on the spot. It’s not a formula to be taken too seriously, it’s just for fun and to get you to think about it. And it is truly loads of fun.

The skinniest tire on the bike should be at least 11 percent larger in diameter than the average diameter of the seat-, top-, and down tubes, and at least 16 percent larger than the front-to-back dimension of the fork.  

You add the diameters of the three tubes. Divide by three. Multiply by 1.11, and that’s your visual minimum.

For the fork, measure front-to back and multiply by 1.16.

Maybe the calculated tire size won’t fit. The formula isn’t designed to make your frame or fork look bad. It’s designed to make your bike look good. Whether it still rolls or not is another issue, but fat tires + skinny frames and forks = hubba hubba.

The seat stays and chain stays are sad to be left out, but there’s a formula there waiting for somebody else to come up with.

Bicycle looks, or aesthetics, are not the most important topic in the world of bikes, but they’re always at least in the background, and I don’t think anybody can deny that they care how their own bike or bikes look. 

It doesn’t matter to me what you like, and shouldn’t matter to you what I like, but Ted and I like the same look, it seems. In bicycle frames, I guess what we’re talking about is the “lead pipe look” of inch or inch-and-an-eighth top tubes, inch-and-and-eighth seat tubes, and inch-and-an-eighth to inch-anda-quarter downtubes … especially when combined with 32mm or larger tires, which make the tubes look even skinnier. 

We don’t make frames out of lead pipes, or anything close. A thick tube has a wall thickness, at the end, of just 1.0mm (1/25.4th of an inch). For most of their length, the tubes in our frames average about 0.7mm (about 1/36th of an inch).

So no, not lead pipes, but the lead-pipe look. Big diff there. (Not more tea; more tea flavor. Remember that one? Lipton has what—-just given up? Commercials now are cars and drugs and sodas, with now and then a fast-food.)

Maybe you have to be old to like the skinny-tube look. For sure, the bikes I grew up with had skinnier tubes still. Schwinn Varsities, for instance, —- I’m sure they had top tubes that were less than an inch in diameter. (Unrelated but noteworthy, their fork blades still hold the most aerodynamic of all time record.) Those Varsities had the skinny-fat thing going on. 

Those bikes were nearly indestructable, and maybe living with them, and old Raleighs, Peugeots, and Motobecanes that basically never died is why I associate skinny tubes with strength.

I know the physic-al advantages of fatter-thinner tubes. More torsional rigidity and lateral stiffness per ounce, but that comes at the cost of dent-resistance  and toughness. Beer cans dent easily, and V-8 cans from the early ’70s don’t (didn’t). Putting more metal between the air outside the tube and the air inside it makes a tube harder to crack or buckle.

There’s a balance between weight, strength, efficiency, durability, costs, and marketability, but there’s not one tiny sweet spot that gives you the best of everything. It’s always a compromise. 

Usually the compromises err on the side of marketability, because sales drive everything, and there are some smart battles that a manufacturer could spend a lot of money fighting, with no chance of success.

For  instance, a good case can be made for straight-gauge (not butted) top tubes and down tubes. A straight-gauge top tube is less likely to dent in a crash, and weighs only about 2.5 ounces more. That it costs less makes it seem worse, but I’d say it’s better. We use butted tubes on most of our bikes, although the Bombadil and the big Homers have straight gauge top tubes—as they should.

A straight gauge down tube resists twisting more, and down tubes are supposed to be heavier than the other tubes. Here again, it would weigh about 2.5 to 3.5 ounces more, and you can lose that much fat in a day easily (not that you want or need to!).

[drew beckmeyer]

thanks joe,

awesome reference. exactly the kind of stated reasoning i was hoping for. 

[Garth]

In regards to tubing of any bike , focusing on tube sizes/dimensions and quality of the steel is okay to putter around, but it overlooks the fact that a bike frame is One Whole "unit" , Complete .  It's not just the tubes, but every detail of it from design, material, shape and bending of tubes and welding it all together that make the frame ride like it does.  Focusing on just one aspect of it alone will never explain the unique , intangible qualities of the Whole Complete Frame .

[Leslie]

On Tuesday, March 17, 2015 at 4:42:55 PM UTC-4, Mike Schiller wrote:

 The difference is about 7 oz for a 60 cm bike ( the .8 mm straight tube weighs more). But the bike will also be stiffer riding as a butted tube is more flexible. But since the diameter is smaller the increase in stiffness is less than similar diameter tubes.

~mike

So on my 56, maybe more like 6oz?  Or 5oz?   Given that I could/need to lose 70lb and would still be a clydesdale, I'm not gonna sweat that weight.     Flexibility:  well, even if the tubing was flexible, once you add in that diagonal tube, I don't think it's gonna be that flexible, regardless of butted or not....   Thing is, I got the Bomba to be a load carrier, not a planing sprint-machine, so, I'm not sweating it.... 

If I want something lighter, I'll take the Ram or the Rom.....

[Deacon Patrick]

Given my Hunq has a dig or two in the middle of the tubes, I'm thankful for Grant's bucking of the market on this one!

With abandon,

Patrick