Is steel real?

You're absolutely right there.

Nothing looks as good as a straight* skinny steel tube. And the most important aspect of a bike is how awesome it looks.

Here endeth the discussion.

*Some exceptions for from wheel clearance or seat tube angling.

I've owned 11 steel bikes and still own two (Kona Bandwagon, Cotic Soul) in a mix of tube standards from (925 all the way down to DN6 :-), and of all of them, only the Indy Fab was really standout to ride.  The Soul was better than the Soda, but the rest - meh.  I'd take Ti and Carbon over steel anyday

Steel is Real(ly dull) in my experience.

For a road bike it's great, not so sure on a FS MTB.

I have an old Diamond Back with Tange Cromo and it's as tough as old boots and I use it daily as a commuter now, carrying heavy panniers. The road bikes are a delight to ride, both high end steel though.

Full suspension though I’m not sure I grasp the theory and compared with aluminium it’s heavy.

Get a demo ride. Don't buy a bike on theory. Or based on claimed weight on the scales.

Some full sus chat...

Nothing looks as good as a straight* skinny steel tube

You're wrong. Even the prettiest bike can look awful in the wrong colour, and even the most gopping can be redeemed a little by the right one. (there is however only so much lipstick you can put on a pig).

I'm also not sure it holds true on an FS where all the gubbins can make those skinny tubes look a bit wrong.

I asked my AI advisor to give a definitive answer:

Some people say “steel is real” because they believe that steel is the best material for bike frames. Steel is an alloy of iron and carbon that has many applications in different industries, such as construction, transportation, and manufacturing. It is stiff, durable, and easy to work with. It can be welded, brazed, or lugged to create different shapes and designs. Some cyclists prefer steel frames for their bikes because they provide a smooth and springy ride quality that no other material can match. Steel frames can absorb shocks and vibrations from the road, making them more comfortable and stable. They also like the classic look and feel of steel bikes, which have a timeless appeal and a distinctive sound.

However, steel is not the only material that can be used for bike frames. There are also aluminum, titanium, carbon fiber, and other composites. Each material has its own advantages and disadvantages in terms of weight, strength, stiffness, comfort, durability, cost, and aesthetics. Aluminum frames are lighter and cheaper than steel frames, but they are also more rigid and prone to fatigue. Titanium frames are stronger and more corrosion-resistant than steel frames, but they are also more expensive and difficult to manufacture. Carbon fiber frames are lighter and stiffer than steel frames, but they are also more brittle and sensitive to damage. The choice of material depends on the rider’s preference, budget, and riding style. Some riders may value performance over comfort, or durability over weight, or style over function.

Therefore, the phrase “steel is real” is not a factual statement, but an expression of personal opinion or preference. It may also be a way of showing nostalgia for the past or resisting the trend of modern technology. Some people may feel that steel bikes have more character and soul than other bikes, or that they represent a simpler and purer form of cycling. However, these feelings are subjective and not based on objective evidence. Steel is real, but so are other materials. The best material for bike frames is the one that suits the rider’s needs and desires.

Cotic use steel on full sussers for performance:

https://www.cotic.co.uk/geek/page/SteelFullSuspension

I've had steel bikes going back to the early  80s for mtb and earlier for road. Good quality tubing makes a difference imo, but the noodly ride of old school 531 etc is long gone outside the retro bike department

I've a 501 rigid, it's horrible but as a town bike so what. I've a prestige p7, it's better but still not really exciting. A 531 tourer that is joyful, and an Alu turner that is lovely

Tldr it depends, and it's horses for course

The only steel bike I've ever had that noticeably had all the steel attributes that get thrown around in magazine reviews was my old Curtis S1. Was a sublime thing to ride and its one of the very few bikes I regret selling (anyone have a medium/17" Curtis S1 frame for sale, let me know). My Soul was ok, my Inbreds were like pig iron (but weirdly I loved the way they rode as well but I couldn't tell they were steel or stiff aluminium). My Evil was like the Inbreds on steroids (absolutely no give whatsoever - sure it'd have survived a bomb blast like my Brooklyn but was steel for strength rather than compliance etc). The only thing that has come close to my S1 in terms of "real steel" feel were a few old decent Konas I used to own (think they were the triple butted ones, not the cheaper Hahannas etc).

Never owned or ridden a steel full sus so no idea how they compare but that Curtis one is fugly IMHO.

Pretty sure steel is a real thing and not a made up material or hologram.

Get a demo ride. Don’t buy a bike on theory.

In fairness I'd be not-buying a bike on a theory.

I like the idea of demoing one of everything don't get me wrong but several of the steel options it's simply not an option eg cotic don't have a flare (though in this particular instance I'm looking at the rocket which they do have in c5) in my size for demo so any demo is guaranteed to feel wrong.
Not sure there's any option to demo a curtis or a ra etc.

Is steel real?

Yes.

Pretty sure steel is a real thing and not a made up material or hologram.

The whole universe is a hologram, you know that right?

but that Curtis one is fugly IMHO.

I like it, but that being said I like blob fish and naked mole rats too.

I asked my AI advisor to give a definitive answer...
... The best material for bike frames is the one that suits the rider’s needs and desires.

Is your AI in politics?

IME the material itself is an irrelevance on FS. Its more how its properties are best used. I've had a bunch of ally FS bikes and am now on my second steel one (both Cotics). The handling, suspension kinematics, UK-conditions friendly design, (and the fact that they're made by my mates!) are all WAY more important than what the tubes are made of. It just happens that Cy prefers working in steel and has some decent reasons for doing so - see that geek link above^^.

Weight is kind of a non-issue - my old 26" Rocket was just under 30lb; my current gen 2 Rocket Max is 33lb both of which seem pretty par-for the course for a chunky trail/enduro bike. (I was pretty horrified that a $10k 140mm travel carbon Yeti in a recent-ish Pinkbike group test was significantly heavier than my RMAx). Yes I'd like it to be lighter, but its the rims and tyres that are the limiting factor, and for my riding I'd rather have a bike that I can rattle rocks off with impunity than have one like my old Intense where the downtube looked like it had been beaten with a ball-pein hammer.

I have the relevant one of these on my steel bike, so there you have it, proof 🙂

It is a hardtail though... but still, it says it right there in black and white, so must be true.

Best and worst cornering FS bikes I've had have been from Cannondale.

Best - Prophet, single pivot, would hold a line and was super compliant whilst leant over.

Worst - Jekyll, super rigid massively stiff (it's was Cannondales marketing blurb for them), was skittish and wouldn't hold a line whilst cornering.

Material doesn't make a difference when the bike is vertical but leant over the suspension is out of plane so doesn't work as much, this is where material makes the difference. Steel can happily flex.
The only issue is where the flex is fed through the shock as it wears the shaft/shock bushes.

Google Ducati GP frame stiffness.

I've got a steel full-sus bike (a Starling).

Yes it works very well, and does what the enthusiasts claim.

It has it's compromises though and not all steel bikes will be so noticeably compliant, e.g. I've ridden a few Cotics and they are probably better all rounders, but less magic carpet-ish.

Definitely ride and decide for yourself.

Love the ride feel of my flaremax gen4. It's incredibly different to my carbon orbea occam. I definitely prefer descending on the cotic, despite it having 15mm less travel.

These are the rules:

1. Geometry = handling
2. Tube diameter = rigidity
3. Weight = material

Steel is relatively heavy and slim in diameter, hence will tend to flex more than alloy and carbon and be heavier. That said I'm with skinny tubes look great, but for a FS bike that is basically squashy anyway, I can't see the point!

Nothing looks as good as a straight* skinny steel tube

Not true, skinny TITANIUM shiny or brushed tubes look event better!

for a FS bike that is basically squashy anyway, I can’t see the point!

See RNP's comment on his Cannondale above...

single pivot, would hold a line and was super compliant whilst leant over.

My Starling has amazing grip leaning over, which I think is when chassis compliance becomes as much or more of a factor than suspension performance.

And it's very comfy and damped-feeling generally.

However I think you have to really value those qualities to choose a steel FS over an alu or carbon one. I'm downsizing soon and my Starling will be first out the door as it's something of a luxury TBH and my other bikes can cover the riding it does.

More flex will find more grip when the bike is leant over in corners - until there’s too much flex and the bike doesn’t go where you point it. The ideal amount will vary depending on the trails you’re riding, and your weight, strength and speed.

There’s a consistent theme amongst reviewers and owners (and great riders like Neko Mulally who’s been testing aluminium and steel front triangles back to back) that well designed steel frames corner better on more natural trails.

Love the ride feel of my flaremax gen4. It’s incredibly different to my carbon orbea occam. I definitely prefer descending on the cotic, despite it having 15mm less travel.

Again, that's geometry, not material.  For a given size the Cotic has more reach, less stack and a longer wheelbase which will make it more stable and thus faster when descending.

.

.

My thoughts exactly

I rue the day I sold my FlareMax. Looking forward to the day when I get another one.

My Crack-n-fail Prophet MX was at the tail end of the 26" era, it was a project I built up with a DHX shock that I'd done some work on and set up as 'mini dh' bike.

I remember being at BPW and holding the bars and back wheel whilst pushing the bottom bracket with my foot as I was trying to figure just why it cornered so well. It was really flexy. My cornering style was/is foot out and forward MX style on fast off camber sweepers.

The Jekyll that followed (I owned them both at the same time) was harsh and pinged off everything when cornering in the same style. It literally skittered wide all the time.

It then cracked after 2months - warranty replacement. Took it to Morzine and hated it that much I sold up and quit mountain bikes for 3years.

Now back on a steel hardtail again. I've had a few aluminium hardtails, Zaskars, Spooky Metalhead, MK1,2 &4 Chameleons, and steel hardtails Evil Sovereign, BMW Park bike, Mk1 Cove, Ragley Bluepig, On-One Hello Dave.

The Hello Dave is the best hardtail I've ever owned. The Bluepig was good in its day as well. Generally steel is better-er.

It then cracked after 2months

Did it then corner better until you got the warranty one?

If I dropped my hard tail on your foot you’d think it was real enough

I ride a Kingdom Hex made from titanium. Beautiful bike. Rides wonderfully. Personally, I don’t think any of that is down to the Ti material. In fact, as fast as I’m aware, the Ti tubes had to be beefed up to cope with being on a full susser.

So if I was looking at a bike, I wouldn’t be swayed by the material. But I wouldn’t be dissuaded by it either - if I liked the idea of owning and riding a Flaremax, I wouldn’t be put off by the fact that it’s made of steel.

Did it then corner better?

You jest, but I was riding my old Orange Stage 6 (a pretty stiff frame) on some very twisty, rooty, wet trails one day when one of the pivot bolts came loose and rounded out.

It had much better grip when I was riding with a bit of play between the front and rear ends. Partly what made me get the Starling TBH.

In future I expect we might see frames with adjustable chassis compliance. I know a couple of small brands are experimenting with features around this now.

We all have our own fluffy perceptions about what can be done with the materials... but I strongly suggest watching that video I posted... it's Specialized's suspension tech/ride guy that's doing the back to back comparison of the steel and alu mainframes bikes for Neko (as it was too soon after his injury for him to do it himself)... someone who has no skin in the game as regards using steel. Now, obviously it's always about "how you use it"... but in the right hands steel can absolutely offer something over other materials, even if geom and suspension tech is kept the same (as in the example in the video). People do tend to think of skinny timetrial bikes of the 80s, or the hardtails we grew up riding in the 90s, when talking about steel. But things have moved on a long way since then, especially with the modern tubesets that Cotic have developed with Reynolds for use on full sus bikes.

Steel FS wise I had a Brooklyn Machine Works Racelink. OMG that was just like riding a MX bike. If you ever watch a Motocross race where a rider gets in a rutted berm and clutches a big capacity 2stroke out of it - thats what the Racelink cornered like.

Again - big vertically stiff frame but very compliant and flexible when laid over with a very long swingarm and linkage isolated shock, short head tube with an 8" travel Avalanche fork leveraging it. That bike loved fast off camber sweepers.

is any actual benefit to me as a rider in its being steel.

I suppose only you can really answer that, but I do question some of the received wisdom when it comes to using steel in a bike frame.

The flex and "feel" thing generally comes down to using skinnier and/or thinner walled steel tubing and you might not want that in all aspects of a frame, at the same time if you want a part stiffer you'll probably end up paying a weight penalty for it.

The other thing is as we're talking about an FS bike made up of multiple components (front triangle, swingarm(s), linkage(s), etc) why does the whole thing (or most of it) need to be made from the same material?

I personally like the idea of a simpler single pivot bike with a steel front triangle and a Composite swingarm (has been done before), the logic being the composite swingarm would be the same moulded item for all sizes and geometry flavours, while the steel front triangle would be where you focus effort on tweaking sizes and/or applying custom geometry.

Off the peg though, where most of us actually spend our own money? Aluminium generally makes sense to me for bouncy bikes paid for by the actual rider: The trade off between weight, cost and crying like a baby when you (inevitably) drop it on some pointy rocks seems to swing in Aluminium's favour.

The trade off between weight, cost and crying like a baby when you (inevitably) drop it on some pointy rocks

In defence of the current carbon one it was a "considered" decision to ride it into the big rock and use the down tube to stop me when my brake blew up halfway down an Italian mountain. I can't imagine a steel or alu frame would have faired better in any practical sense.

Is any full-sus real? Once I bought a 120mm full-sus bike (pivot switchblade) and I just felt overbiked and took the fun out of riding so I went back to a hard-tail for a more 'real' MTB experience.
Admittedly it may be because I don't ride on real trails so need a more real bike to create a real riding experience.
The challenge here I guess is to come up with a formal expression that equates the real and imaginary parts of bicycle and trail attributes? This would allow one to equate whether a particular combination meets a given threshold of realness.

The fact that Cotic have added a downtube to seat tube brace on the FlareMAX5 says that the area warranted some stiffening, and the much talked about steel properties were there in the Gen 4 - maybe a bit too much for some. I have a steel full sus bike (Cotic Flare), but mostly just because I like Cotic bikes, the colour, and how it test rode. From what I've read over the years, the slight flex you can get from steel helps with a bit of extra grip, and perhaps some extra damping, but this is mostly beneficial when leant over/cornering rather than in a straight line where the suspension should be taking care of things.

I personally like the idea of a simpler single pivot bike with a steel front triangle and a Composite swingarm (has been done before)

But the examples I've seen look horrific 😀

Cotic's approach of using aluminium for the chainstays (or is it seatstays? or both?) makes a lot of sense though, and they ride very well.

Chainstays/swingarm with all the big cast/machined parts are aluminium. Seatstays are steel.

Prototype carbon rear ends have been tested and rejected by Cotic a few times.

Youre all looking a this all wrong.

Its a Push bike. and an off road bike at that.

Do you like the Curtis?
Do you want the Curtis?
Can you afford the Curtis?

Buy a Curtis*

(* Test ride a Curtis first)

I see it a bit like Morgan building bits of their cars from Ash, they don't essentially do it because it's better, they do it because they can and people will buy it because it's a bit different and it makes them stand out from the crowd.

Over thinking decisions is half the fun isn't it?
Also the whole purpose of this place is to ask for various opions then ignore them all - including your own.

@daffy yes geometry plays a part but it's not the whole story. The flaremax is a tiny bit slacker and a tiny bit longer but the difference in feel between the two goes way beyond that. I never believed the steel is real hype and didn't have high expectations of the cotic but was really surprised just how much more compliant it is when descending rough stuff.

I’ve a prestige p7

The P7 has never been made from Prestige tubes. It sort of replaced the Prestige in the line up back in 93 but was always a very different bike.

I like my steel Pace and Ragley + reckon the material does add something to the ride but I also love my aluminium full suss. I'd just get the one you like the look of.

@daffy yes geometry plays a part but it’s not the whole story. The flaremax is a tiny bit slacker and a tiny bit longer but the difference in feel between the two goes way beyond that. I never believed the steel is real hype and didn’t have high expectations of the cotic but was really surprised just how much more compliant it is when descending rough stuff.

As a mechanical engineer, I really have a hard time believing that what you're feeling as compliance can be the difference in the way the STEEL tubing moves over how the AIR suspension is working on it's linkages.  Only at the very max level of shock compression would the tubes possibly start to bend.  If we've talking about the bike bending out of plane, again, it's more likely to happen around the linkages, than it is at the tubes.  The one exception may be at the bottom bracket. where the linkages are having little effect and its more to do with the downtube and chainstay stiffness.

I have had steel, ally and carbon MTB and road bikes. The only one I could tell any difference with was a particular ally road bike that was so harsh it rattled your fillings. The only other difference was the carbon ones were lighter and easier to pedal uphill otherwise it's down to what individual manufacturers do with their materials

The only other difference was the carbon ones were lighter and easier to pedal uphill

And the steel ones looked better...

@daffy I appreciate you're actually qualified to discuss these things and I'm just a unqualified bozo who rides the bikes. All I can report is my perception. I've no idea where the compliance comes from, whether it's linkages or tubes. As core mentioned above, the new model has an extra brace joining the BB, downtube and steattube, which is presumably to increase stiffness in that area. If the ride feel is nothing to do with frame material then I'd love an alu or carbon flaremax to save some weight.

Steel is real until you realise titanium is better.  Lol

Steel is real until you realise titanium is better. Lol

My ti hardtail will disagree.

@daffy I appreciate you’re actually qualified to discuss these things and I’m just a unqualified bozo who rides the bikes. All I can report is my perception. I’ve no idea where the compliance comes from, whether it’s linkages or tubes. As core mentioned above, the new model has an extra brace joining the BB, downtube and steattube, which is presumably to increase stiffness in that area. If the ride feel is nothing to do with frame material then I’d love an alu or carbon flaremax to save some weight.

I just think they're two very different bikes and the combination of geometry, suspension dynamics and possibly weight do make the Cotic feel immeasurably better, and I have absolutely no doubt that you can feel it.  Additionally, I full appreciate that material can make for a vastly different feeling.  Carbon wheels built the same way as alloy wheels are (for me) far too stiff.  I reduce the spoke count and the crossing to make them feel better for me.

Steel is real until you realise titanium is better. Lol

Until it cracks!! Imho the bike industry standards of welding ti aren't good enough.

Just look at this thing though. Just look at it! Its virtually pornographic

I have, quite a bit binners, though not that specific one (I'm guessing it's not yours as its not in blue and yellow livery)

Thing is, it's not inexpensive (it is for what it is mind) and as the saying goes you don't look at the mantlepiece.
I want to like it very much and that will likely render any demo I might get rather superficial become, you know, I've already decided I like it.

I'm mainly looking for someone to tell me its all hype and buy the (whole) saracen instead or the opposite, obviously.

Just look at this thing though. Just look at it! Its virtually pornographic

I'll take a modern carbon full sus over that Land Rover chassis any day.

[i

Just look at this thing though. Just look at it! Its virtually pornographic

I don't know how the shocks are mounted on these (spherical bearings?) because it's a whole lot of loading that is being dealt with by the shock. It will corner very well though

Just look at this thing though. Just look at it! Its virtually pornographic

Sorry but the swingarm just reminds me of the late nineties bottom of the range Marin single pivot thing.

I’m sure it’s a lovely bike tho.

I don’t know how the shocks are mounted on these (spherical bearings?) because it’s a whole lot of loading that is being dealt with by the shock.

It's an x2 so it'll blow up long before that's a concern

If we’ve talking about the bike bending out of plane, again, it’s more likely to happen around the linkages, than it is at the tubes. The one exception may be at the bottom bracket. where the linkages are having little effect and its more to do with the downtube and chainstay stiffness.

In the plane off the bike I’m with you all the way. Even more so on a hardtail

But all bike are really bendy out of the plane. Stand next to any bike and press on a pedal with your foot. So it sends entirely plausible a stem FS is much more flexible out of the plane of the bike

Binners , that swingarm looks like a borked umbrella.  I've had steel, I've had carbon and I know which one I prefer.

And it's not for Titanium, the 'bike for life'.  But not a very long life. And they all look the same

Imo Curtis' are suited to hardtails only.

I'm sure it's an alright kinda ride though. Why not buy a Tranny full suss and build a Curtis hardtail. Think of it like a N+2 😁

I personally like the idea of a simpler single pivot bike with a steel front triangle and a Composite swingarm (has been done before)

But the examples I’ve seen look horrific 😀

Even the Swarf Curve?

It was like a decade ahead, high pivot idler and everything...

I’ll take a modern carbon full sus over that Land Rover chassis any day.

That, and a Santa Cruz I saw on here today both have horrific head tubes. Looks like it's unfinished and reminds me of the bottom bracket area on my old Whippet. Pretty sure carbon full suss bikes used to look better?

As for the Curtis, agree that the rear end looks like a early 2000's BSO unfortunately as I want to like it.

I ride an Orange full suss though so what do I know, right?

“ As a mechanical engineer, I really have a hard time believing that what you’re feeling as compliance can be the difference in the way the STEEL tubing moves over how the AIR suspension is working on it’s linkages.”

Stop thinking in 2D. Lean the bike over and consider all the force vectors when cornering. The forces are big, the levers are long (front and rear contact patches to grips and pedals) and there’s not a lot of material in any bike frame, even a long travel steel full-sus. They bend!

@kelvin - can you elaborate why Cotic rejected all the carbon swing arm prototypes? I’ve always wanted a Cotic, but I’d be much more interested if they had a repairable (steel or carbon) rear end. My main issue with alloy on expensive full sussers is that when it cracks it’s doomed to the bin - at least carbon and steel can be relatively easily and cheaply fixed. Obviously not an issue if the alloy frame has a lifetime warranty, but smaller brands usually only have a few years, plus then it has ramifications for the second hand market (which in a world where we need to recycle things for longer isn’t great).

You’re wrong.

no, you’re wrong

Get a demo ride. Don’t buy a bike on theory.

you mean hypothesis.

I do favour steel bikes (Cotic fanboi) but will happily admit that it's more a philosophical and aesthetics thing than anything I can easily or measurably feel in ride dynamics.

In fact, the absolute stiffest and most uncompliant bike I have is a steel one. My BFe feels like it absolutely refuses to bend in any plane. Probably the fact that it's a tiny 14" frame has a lot to do with that but when I first got it it was noticeably stiffer at the rear than it's predecessor which was an Identiti Mr Hyde who's rear triangle was made from thick square section (aluminium) girders.

And then, the smoothest bike I've owned was an Orange Alpine 160. massive aluminium frame but buttery smooth single pivot suspension. Having said that, I know from regularly riding behind a mate who also had one that the single pivot rear end on those bikes was laterally and twisterally (?) all over the place to a scary looking extent which I guess negated any harshness inherent in the frame.

TLDR. Buy whatever bike built from whatever material that you can afford, does the job you want it to,  and (most importantly) like the look of. Unless you're a world class rider, then differences in ride quality due to frame material are likely to be way less noticeable than other factors.

Stop thinking in 2D. Lean the bike over and consider all the force vectors when cornering. The forces are big, the levers are long (front and rear contact patches to grips and pedals) and there’s not a lot of material in any bike frame, even a long travel steel full-sus. They bend!

So when I explicitly stated “out of plane”, so expressly NOT  2D, and that there would be some feel? Of course they bend, but I’d wager it’s bending more at the joints/linkages between the main triangle, shock and swingarm than it is in the steel tubes of the front triangle.

Daffy, (at the risk of sounding patronising here!) the frame tube flex that's being talked about here is mostly twistiy along the line if the head tube, seat tube and rear axle. Suspension movement reduces many of the forces causing that but a rider hauling on or loading a wide bar with majority of their weight going through one pedal can put a lot of torque through a frame in a corner. The whole frame can flex (depends on material and design oc), the suspension compresses but that doesn't take out all forces and it can takes surprisingly little sideways force to deflect top and down tubes so that the seat and head tubes are out of line.

Even the Swarf Curve?

OK, I hadn't seen that. Looks pretty good.

I was thinking of stuff like this...

Daffy - The forums and comments sections are full of engineers in unrelated fields saying that steel bikes can't possibly feel different to other materials "because science". Yet subjective reports from people who have actually ridden them say otherwise.

How do you reconcile that? Are we all gullible fools? Or could you perhaps not have the grasp of the subject you think you do?

Sorry but the swingarm just reminds me of the late nineties bottom of the range Marin single pivot thing.

I was thinking shopping trolley myself.

Cha****ng  - in defence Daffy, there are great many reasons why subjective opinions aren't considered scientific, as there are far too many confounding variables. Nothing is standardised. The riders aren't blinded, so they wander into any assessment with their own expectations up and running. The trails will be different, or the conditions will be different, or the tyres, or the geometry, or whether the rider had a poo that morning, or or or. And then there's the idea of what 'better' is in a given context anyway? Faster? Poppier? More fun? More gooderer at corners? What constitutes 'more gooderer' anyway?

It is *spectacularly* hard to remove any and all variables from this debate (which, of course, has been going on for decades). No, you're not gullible fools - but you are human. The idea of 'science' is to try to remove the 'human' from the scenario. Something that an internet forum is somewhat crap at doing.

Something that an internet forum is somewhat crap at doing.

I don't know about that. Go read some of the politcs threads. You'll have most of the human removed from you quite quickly (start somewhere over halfway and I wager a shinny £1 coin it'll be completely gone by the bottom of whichever page you landed on).

Daffy, (at the risk of sounding patronising here!) the frame tube flex that’s being talked about here is mostly twistiy along the line if the head tube, seat tube and rear axle.

This topic comes up repeatedly, with the same arguments being made every time. A few years back, Brant explained that the major point of flex is around the junction between the top-tube and head-tube. Depending on the frame design, you can apparently get a lot of flex there, and not just torsional.

The stiffness of a tube is mostly down to the diameter and aluminium is much less dense than steel so you can use larger diameter tubes, but build a lighter frame. It would be possible to build a flexy aluminium frame if you used small diameter tubes, so the flex is not intrinsic to steel, it's down to the design of the specific frame.

“Of course they bend, but I’d wager it’s bending more at the joints/linkages between the main triangle, shock and swingarm than it is in the steel tubes of the front triangle.”

But why? As an engineer surely you understand that it’s easier to bend a long tube than a short linkage if both are built to withstand similar forces before failure?

“The forums and comments sections are full of engineers in unrelated fields saying that steel bikes can’t possibly feel different to other materials “because science””

As another engineer this continues to drive me crazy. I see it in other fields too. I don’t understand why so many engineers massively over-simplify things that are outside their specialist field.

My late grandpa was a very talented electronic engineer who worked on pioneering computer hardware throughout the second half of last century - but I remember him saying he couldn’t understand why you’d have wider tyres on a car because the contact patch is defined by the tyre pressure and vehicle weight…

The idea of ‘science’ is to try to remove the ‘human’ from the scenario. Something that an internet forum is somewhat crap at doing.

And bike product reviews are a total waste of time as well then.

😀

so the flex is not intrinsic to steel, it’s down to the design of the specific frame.

That's not entirely true, yes you could make an alu frame that deforms similarly to steel but the way it handles that isn't the same. How they work harden, how plastic they are etc are properties of the material so you could build an alu frame that bends like a steel frame but in so doing it will be more (or less) likely to snap, permanently deform etc.

As such depending on what material you use the amount of acceptable deformation will change and there's only so much you can tune that with tubes.

The bigger question is if there's any benefit to a frame that flexes to 11. (or indeed downsides like those specialized strut* frames that ate shocks)

*might be wrong on that but I seem to recall it was the strut design on the enduro and something else