There are fatigue tests – I think for a German mag – that will back this up – and the CEN tests are just a fatigue test too, after all. If steel frames were failing it, what does that say for their durability?

Do not confuse strength with durability.

And that’s fine, if that’s how you want your bike to ride

I do. I like it.

I like my nice supple tyres and flexy seatpost more.

Sweet, I was beginning to think that I’d imagined it all and it was all just marketing BS Bingo…

Nice bit of selective reading there 😉

Re-read Jameso’s post, vertical flex in the rear end is, especially in the chain stays, negligible and lost in the noise of flex elsewhere, most notably top tube, seat tube and downtube. The rear end of a traditional double diamond frame is just too well triangulated to have much effect and is alway going to be overshadowed by the other bigger ones.

Ovalising tubes does effect the way the flex, and nobody would or could dispute that, but those chain stays are not what makes your PP so comfortable, it’s all the other stuff!

I still think the biggest advantage that steel has is just how sexy it looks, especially on a hardtail with a big fork.

I’d suggest the Jones and PP rear stay ovalisation adds sideways stiffness but makes little (or less..) difference to vertical give since vertically it’s a triangle, a small one at that on the PP.

I suppose it’s not something many will have studied in any real depth, you’ve more experience of such things than most of us.
You raised a good point about triangulation of the rear end members on the PP too, the stays are at a reduced angle, due to where they meet the dropped TT/Seat tube, along with that “Transverse ovalisation” (do you like that one?) you might get some sort of combined flex/vibration damping effect?
Lowering the Seat stays as PP have should also affect how the rear end deals with side loading and torque when leaned over, so is that ‘more comfortable feeling’ perhaps more lateral deflection, but again might that be slightly counteracted by the squashed stays?

Having looked at some images of the OKA they seem to have ovalised the Chain stay in the same way too, I’d think that should have more of an effect in terms of “Softening” the rear, you’d expect them to bend the Seat stay, adding say a full length curve or some ‘S’ bends, off of the tube’s axis to make it bend slightly under compression (a’la Jones) but they haven’t it’s arrow straight…

It’s difficult to see if its all part of a clever design, or just aesthetic, or something in between, either way the back end of that frame is not “Standard” in it’s construction…

I still think the biggest advantage that steel has is just how sexy it looks, especially on a hardtail with a big fork.

Aha, someone has sussed the reality of life with a modern steel frame 😉

the CEN tests are just a fatigue test too, after all. If steel frames were failing it, what does that say for their durability?

Interestingly when the CEN (now ISO) tests came in the test for front end fatigue -the big fork lever test- broke a lot of steel bikes at first, steel bikes that in use generally outlasted the average pre-CEN alu frame many times over, most of those alu frames could pass the tests. One conclusion was that the loads x no of cycles of some CEN tests were fatiguing frames in a way that didn’t represent real-world riding but the tests needed to take 12hrs not 12 years. It’s simply a test of relative durability.

A lot of what I think has already been said above, but basically if a frame is well designed for purpose to which it’ll be used, the actual material is down to personal choice and aesthetics.

Steel is stiffer than aluminium per volume; aluminium also fails catastrophically at the end of its fatigue life (especially the welds), which is why, in the ’90s, it tended to be built into very stiff frames using large cross section tubes to prevent any flex. Frame manufacturers are a bit more savvy now, though, with how they use the materials; well engineered stays, bending uniformly along their length, are remarkably resilient. Hopefully, gone are the days of Cannondale head tubes coming undone on the trail!

For years, the industry made aluminium seem more ‘high tech’ when in fact it was just cheaper to manufacture a flash and gimmicky frame in aluminium. Some of us old gits will never fully trust aluminium as an investment, compared to something like a Pace RC127 in Reynolds 853, which is ironic as Pace always used to make frames out of Aluminium!

I’ve just renounced my steel fanboy club membership. I liked my 45650b, but not as much as I liked my 456 evo 2. I think the reason is because the seatstay arrangement on the evo did allow a bit of vertical compliance, whilst the burlier 45650b was way more stiff. The 45650b has cracked and I’m waiting on a warranty replacement.

In the meantime I did a bit of thinking and came to the conclusion that I was carrying a good 1-2 pounds of extra heft on the 45650b for the promise of a steel feel that was never going to be there on account of how ‘built’ steel frames tend to be – especially since CEN.

So now I have bought and built up a Dartmoor Primal 27.5 – although I have yet to take it on its maiden voyage. I reckon I might as well go back to chunkier aluminium to gain a weight advantage whilst not giving up anything in terms of comfort. Time will tell of course, but the Primal looks amazing!

As people were talking about FEA and compliance, I had a very quick go at modelling a chainstay (10 minutes all in, so very basic!).

Modelled up a Columbus spirit stay (30×17 ellipse) loaded against either axis (stiff vs. compliant) and a 22.5 dia round stay (as it’s the same amount of steel) and applied a 1kN load at 440mm from a fixed end.

Obviously this makes no allowances for seatstays, welding and seat-tube flex, but the displacement of the stays at the point of load were 37, 90 and 61mm respectively in the 3 cases.

Triangulation from the other tubes will obviously remove most of this, but there is clearly an effect to play with – I’ll see if I can get my Y13 Engineering class to work on modelling the whole triangle later on!

I’ve read the scientific stuff with interest but, as most of us know, that plays a minimal part of a bike’s “realness”. It comes down to aesthetics, the rides (and company) you’ve had on a bike, it’s colour, brand, price… a million things have a larger effect than millimeters of chainstay flex.

The first bike I ever, properly loved was a Zaskar. After that I went through a FS phase. We’ll ignore that.

Since then, a few Alu FS’es but, on the whole, steel hard tails.

The best bike I’ve ever owned – and still do – is my 853 Inbred. It’s a little too small for me but it just seems to respond in a way nothing else ever has. I really can’t imagine a custom built frame suiting or fitting me any better. The ‘regular’ Inbred feels a little more dull and sluggish. I know this is comparing steel and steel but it does suggest that frame material makes a difference.

My current bike is a Dialled Alpine. I’ve no doubt that the steel feeling is killed by its sheer overbuiltness, but a nice Reynolds sticker is worth a few grams. Pleasingly narrow tubes too make it worth it. I recently enquired as to the cost of a tapered headtube being welded on. It was a bloody fortune and could never justify it. I’d happily fork over the money for a new BB shell or what have you to keep the bike running.

I nearly bought a Dartmoor Hornet. It was close to my home and the seller offered a ride on his local trails before stripping it. It isn’t nice to look at with its enourmous diameter tubes and it felt harsh as hell. It felt cheap. I bought him a couple of pints having had a fun afternoon but the bike buzzed like a skateboard.

Nothing scientific there but I do believe steel is real. It makes better bikes. Better being entirely subjective, of course.

philjunior – Member

the CEN tests are just a fatigue test too, after all. If steel frames were failing it, what does that say for their durability?

If frames that weren’t failing in real use failed the test, what does that say about the test design?

tall_martin – Member

The magazine tested this year’s ago. They had a black and white charge hardtail in. Anyone who rose one had to ride the other and describe the differences. One was lighter by an amount you would notice in a magazine test but that wasn’t commented on much. Other than that people didn’t describe much difference.

As Jameso says, that tells you something about those 2 frames. Only mugs think that all frames of a similar material ride the same

You could run the same test with 2 different years of 456 and have people feel a difference (frinstance). Or the abovementioned gen 1 scandal vs inbred, where you’d get the opposite result from cliche. But equally you could repeat the Charge test with Cotic, and there’s practically no chance people wouldn’t feel a a difference between my old Soda and my BFe

(there’s always the oblivious outliers who can’t tell when all their pivots are seized solid or their shock has 20psi in it)

If frames that weren’t failing in real use failed the test, what does that say about the test design?

like i said, i ripped the head tube off one of my pre-CEN test steel frames. I’m glad someone’s keeping an eye on these squirrels. 😀

kaya23 do you think Trek, Spesh etc. don’t ride bikes? The difference is they can employ many people to test, provide feedback etc. and have done as much innovation in recent years as anyone, for example the Trek Superfly 29er almost instantly became the XC bike to be riding.

Del – Member

like i said, i ripped the head tube off one of my pre-CEN test steel frames

And people do the same to CEN-tested frames…

sounds like the tests need stiffening up! 😆

dragon – Member
kaya23 do you think Trek, Spesh etc. don’t ride bikes?

Well yes I’m sure many of them and their employees do, but perhaps as a percentage of the entire workforce, it may be higher for smaller brands. I just imagine that smaller companies are perhaps not so absolute and ‘tuned’ in their marketing budget.

Rightly or wrongly, I imagine the marketing BS generators are stronger and larger at much richer companies.

There are fatigue tests – I think for a German mag – that will back this up – and the CEN tests are just a fatigue test too, after all. If steel frames were failing it, what does that say for their durability?

Do not confuse strength with durability.
Don’t confuse fatigue life with strength. The CEN test was a fatigue test. It wasn’t measuring any other form of durability.

Of course if we’re talking ability to resist dents, there are too many factors – a lightweight steel (or ti) frame will be tinfoil thin, but have smaller diameter tubes, whilst Al. will have larger diameter thicker walled tubes. Carbon won’t really shatter if you so much as look at a rock, but can suffer in impacts (and can be designed to take a reasonably large impact).

As with anything else, it’ll come down to how it’s been designed as to whether it’ll survive a blow.

35 years ago I came off my Raleigh Budgie(hi ten steel) on a fast road descent and knocked myself clean out !

I’m now bombing Downhills on my genesis io(Reynolds 520) not knocked myself out yet 🙂

Guess cheap steel isn’t real but good steel is more real ?

Northwind – Member
Del – Member
like i said, i ripped the head tube off one of my pre-CEN test steel frames

And people do the same to CEN-tested frames…
2 good points…

I would guess fewer CEN tested frames fail, but some are still going to. Hopefully bikes are getting better, and stronger where they need to be, but some will always fail and anecdote isn’t really proof. I’ve seen cracked frames in all sorts of locations, head tubes ripping off aren’t good and even if it only happens to 1/1000 bikes, that’s a lot of people having at best a nasty accident…

There is a video on the Jones website, where Jeff demonstrates the vertical flex in a Ti Spaceframe. Ok, it is a Ti frame, so there is that, but you can have vertical compliance and lateral stiffness.

I’d be interested to see a video of the same demonstration with a steel Spaceframe.

FWIW I have to agree with Kayak23, I had a PP Shan for a bit, and it was by a country mile the nicest riding steel HT I’ve ever been on, and like many here I’ve had a few. Really smooth, really forgiving,

TBH I thought the ovalised stays were marketing BS, I put it down to the length of the TT, a long unsupported tube. That, and it’s predecessor was a SC Cham, so damn near anything would have felt softer!! 😆

I’ve got a Bfe. I had a Canyon Spectral. I prefer the Bfe as I just prefer hardtails and this is easily the best I have had and I have had a few. If you could stretch to a Soul I would imagine it’ll be betterer but the Bfe is great too. Here it is..

I dunno if it is because steal is more “real” or because it is marketing hype that I have never managed to shake. I DO know that the only bike I loved instantly it was a Cotic Soul and it remains my favourite bike and the only one will I not ever sell. I have had it around 8 years now and keep coming back to it.

Materials aside, one of the biggest contributing factors to how comfortable a bike feels (assuming hardtail) is down to wheelbase growth and one of the biggest factors in this is toptube and downtube flex. Much more than shaped stays (again assuming traditional diamond frame.

Shandcycles, assuming the same tube shapes (if possible), are pre-CEN top and down tubes more flexy/comfortable/zingy/real than post CEN tubes?

one of the biggest factors in this is toptube and downtube flex

This now makes sense as to why mrs_OAB’s Superfly has such a flattened top tube.
Noticeably, she thinks the superfly is less comfy than the old Cannondale F900sl, but that was made out of very, very thin alu (I can flex it like a drinks can on the downtube – careful with that bike rack now 😯 )

I know very little about the science of frame design but am aware of the argument that most ‘comfort’ in a steel frame comes from toptube flex. However, just to add my experience to the mix, I moved from an 853 Inbred (lovely and comfy) to an 853 Pipedream Sirius. The Sirius felt a perfect fit but very harsh at the back compared to the Inbred. Later I moved to a 853 Pipedream Scion (which I still ride and love) which felt instantly much more comfortable. The Sirius and the Scion have identical geometry and tubes, with 1 notable exception; the Sirius has 19mm seatstays whilst the Scion’s are 16mm. I don’t know why it makes a difference, but it does (as Pipedream claimed it would when I asked about it); it can’t all be in my head.

It’s worth remembering that steel is greener than alu, to do with carbon footprint involved in making the frame.

Add that a nicely made frame can have the nice ‘zing’ and sense of feedback about what’s happening under the wheels too, and that’s a good mixture I think…

It’s worth remembering that steel is greener than alu, to do with carbon footprint involved in making the frame.

It is? Sauce?

Sauce?

Will this do/work?

Linky

Aluminium needs 10times the processing energy of steel…

It’s not just the frame. Wheels/tyres make a huge difference.

Aluminium needs 10times the processing energy of steel…

I did not know that!

It’s worth remembering that steel is greener than alu, to do with carbon footprint involved in making the frame.

While that is true, the steel market globally is massively oversupplied compared to that for aluminium (steel 15 million tonnes, aluminium 277,000 tonnes). So in reality there isn’t a compelling environmental reason to buy one material over the other.

Yes but most aluminium products are not made from virgin aluminium. It’s usually made from aluminium that has been recycled multiple times, and it takes about 5% of the energy to recycle aluminium than to make it new. Same with Steel products, but not sure of the relative energy requirements and environmental impact of recycling aluminium vs. Steel.

wobbliscott – Member

…not sure of the relative energy requirements and environmental impact of recycling aluminium vs. Steel.

i think… that’s covered in the link.

or not…

I think using the energy requirements to extract the raw materials is fine if you consider the other energy requirements, and the energy requirements of making the other (mostly aluminium) bits of the bike.

Might be worth worrying about for a tonne or so of metal, less so on a 1-3kg frame that you’ll keep for 10 years or more.

On the theme of Recycling
http://www.bike-eu.com/sales-trends/nieuws/2017/1/british-steel-magnate-to-bring-bulk-bike-making-back-to-uk-10128606

Ten times more energy to produce? Well crikey…

I just went and found a summary of that CSIRO report and you are correct.

Of course globally we also produce 24 times more steel than aluminium, and hence the process is probably better refined and marginally more efficient for steel…
They make the point that both steel and aluminium production could be made more energy efficient especially for smelting, where both expend the majority of their embodied energy…

Steel is the bigger source of CO2 emissions, but only due to the huge volume produced. Per ton aluminium is the worst polluter (CO2).

Of course that’s only looking at ingot production. There’s no through life analysis, Aluminium apparently uses ~1/4 the energy of steel for recycling, and there’s not really any analysis of transport or eventual manufacturing energy use/derived emissions, nor is there much consideration that at 1/3rd the density of steel, a ton of aluminium goes further (volumetrically)…

I will accept it’s a pretty energy intensive material to pull out of the ground and refine, but for it’s full life cycle, there’s a fair few ways it claws back some ground… I am still not convinced it’s substantially “worse”…

Does anybody actually care about the C02 credentials of their bike frame?

I don’t, I care what it rides like, then what it looks like. It’s carbon footprint will be tiny in real terms.

I ran over and killed a rabbit on my bike once too.

Does anybody actually care about the C02 credentials of their bike frame?

Well it was cited as another way in which steel is more betterer.

Do I care? I guess I do, but it’s not top of the list, of course if prices for goods were properly linked to emissions and energy use, then I bet you would care more…