(apologies for slightly road bike focussed post, but I think it applies to MTB too)
I recently read an article that questioned the performance value of amateur cyclists buying fancy carbon road bikes, when Marco Pantani's Alpe d'Huez record set in 1997 on his aluminium Bianchi still stands. Obviously that was in the doping era but doping continued some time after that on carbon bikes and Pantani's record remains untouched.
Also came across the following article, which argues that the perception of certain frame materials (particularly steel) feeling more comfortable is a placebo effect. Almost all compliance comes from the tyres and seatpost, making the frame material insignificant. The construction of a frame is also more important than its material. The article only concedes one point which is that carbon may be better at vibration dampening for skinny tired bikes.
If you accept that frame materials giving you superior performance or comfort is largely a marketing fib, surely that makes aluminium the best overall material. It's cheaper than the others, lighter than steel and titanium, more eco-friendly than carbon and titanium, doesn't invisibly crack like carbon can, doesn't rust like steel can. You can spend the extra savings on nicer components, which are more important to the experience of riding.
Now I think people should buy whatever bike they want, or whatever gets you out riding. One point I will agree with is that carbon, titanium, and steel bikes can all be aesthetically lovely in ways that alu bikes are usually not.
I'm struggling to reconcile the articles above with the number of people who say steel just feels better to ride or who are absolutely in love with their titanium bike. Or who say the stiffness of carbon is key. Is frame material important or should I just buy alu bikes and ignore the hype?
Buy stuff that makes you go in the garage and want to ride it. I’ve got some Alu bikes some carbon. Certainly no alu frame can do what the carbon topstone does with frame flex and a single sided front end.
But the end of the day you just need to want to ride it.
Never owned a carbon bike frame, quite a few Aluminium and steel.
I’ve never had a steel frame crack.
Almost every aluminium MTB has cracked.
Judging by my road bike, aluminium is certainly capable of corrosion.
Vertical compliance is largely tyres and seatpost. Torsional compliance isn't, so they do ride differently in a non-placebo way (though arguable which is better or worse).
I can't make an aluminium frame in the shed (no heat treatment facility, no AC TIG welder and very limited availability of frame tubing in the UK).
I can and do make the occasion steel frame in the shed. And if I fancy a change, it is possible to cut them up and re-use bits (not just recycle).
I have alu bikes, carbon bikes, steel bikes and a titanium bike.
There's no way I could tell the compliance of a full suss, so break it down to two steel HT's, carbon gravel bike and an alu HT.
Discounting the gravel bike as I have nothing to compare it to, but naturally it feels the least compliant.
That leaves the HT's - the alu Big Al by far feels the most compliant over the steels.
I have no idea what that tells me 😂
I've never snapped a frame though
I'm struggling to reconcile the articles above with the number of people who say steel just feels better to ride or who are absolutely in love with their titanium bike. Or who say the stiffness of carbon is key. Is frame material important or should I just buy alu bikes and ignore the hype?
The problem is that when someone buys a product (any product, not just a bike) with their own money, they feel the need to justify that purchase. Very few people will say "yes I bought this titanium bike and it's a total pig, what a waste of money". They'll wax lyrical about its magical ride properties, how easy it is to keep clean and so on based on the popular conceptions of the time about it. It's very difficult to get an objective sense of "best" based on people who actually bought it with their own money (or pros who are being paid to ride / promote it).
Mainly, you can build an excellent bike or a total dog from pretty much any reasonable frame material (reasonable as in, I'm not talking about some extreme of building something out of lead) but most of how it handles will come down to the geometry and the components. If you put some rock solid wheels with 20c tyres at 120psi onto a super comfy carbon frame, it'll still feel shite compared to a more solid frame but with decent wheels and 30c tyres at 65psi. Likewise if you build something with wildly "wrong" angles, it'll feel like shite compared to exactly the same material but built to modern acceptable geometry standards.*
I don't think there's a "best" frame material at all. There might be "best" within a certain budget, "best" for road racing, "best" for durability, "best" for money no object and so on but there is no one "best".
*this analogy doesn't quite hold up because different size bikes are actually built differently to compensate for the bigger bikes usually having bigger/ heavier riders on board vs smaller framed bikes and the fact that some parts, notably wheels size, generally stay consistent across the board so both a S and a XXL frame will still have 700c / 29" wheels for example.
I'd consider carbon and steel both more repairable than aluminium, so there's that too.
I don't think it's the frame material so much as how it is used that makes a difference.
Steel is strong enough in nice thin, thin walled tubes, which allow more flex, my go-to bike most of the time is a steel hardtail.
My aluminium FS (Bird AM9) is predictable and IMO stiff enough, but I'm not racing it. When racing you want total predictability that comes with stiffness.
Bikes with big fat down tubes are going to be stiffer due to the shape, hence big ebikes IME are brutally stiff & though I haven't ridden the Cotic, I can see where the article last week is coming from.
So one article is right and every other article and people's views and understandings from their own experiences are wrong? Must be right then!
So one article is right and every other article and people's views and understandings from their own experiences are wrong? Must be right then!
Yes because it's backed up by data and engineering studies rather than anecdotes. But I'm also keen to hear how it aligns with peoples' experiences. If you have any disagreements with the content of the article instead of just sarcasm then I'd love to hear it.
I recently read an article that questioned the performance value of amateur cyclists buying fancy carbon road bikes, when Marco Pantani's Alpe d'Huez record set in 1997 on his aluminium Bianchi still stands. Obviously that was in the doping era but doping continued some time after that on carbon bikes and Pantani's record remains untouched.
The performance value of an expensive carbon road bike is absolutely minimal to an amateur cyclist, but so what...? Life's too short to ride shit bikes!
In all seriousness though... If we're looking at Pantani as an example, I know more than a little bit about his bikes of that era... I've been lucky enough to spend a bit of time around one of the bikes he rode in his successful 1998 TdF challenge, and it was, as you might expect, absolutely bang on the 6.8kg UCI weight limit...
Some things to consider though... Pantani was about 60kg wringing wet... Capable of putting out huge power numbers yes, but he was subjecting the bike to the constant pummelling over rough surfaces due to gravity that your typical amateur would... Also, and perhaps more significantly... Pantani's aluminium frames were lifed, and they had a very short life at that too! His alloy frames back then were as light as mainstream carbon frames are now, but my god they were fragile! I can't remember exact figures, but I understand he went through more than 20 race bike frames (identical road bike frames, not counting TT bikes and not counting training bikes) in 1998, typically a frame being deemed "done" after only 3 or 4 days racing...
From what I've seen, the lightest realistic weight of an aluminium road bike frame in a middling size that could be expected to last a few seasons underneath a typical rider who looks after it and doesn't crash it, is around 1.4-1.5kg... For steel, that figure is probably up around 1.8-2kg... Carbon...? Well you're looking at half the weight of the alloy frame and it can more readily be made stiffer or more compliant as required. For sure, the carbon frame will cost 6-8x that of the aluminium frame to buy, but that's only a problem to anyone who buys their own bikes and needs to justify the purchase criteria... Basically, nobody! Combine that with the fact that for pro teams at least, a 750g carbon frame is many, many times more durable than a 750g aluminium frame like those Pantani raced, and simply not needing to change the frame every 3 or 4 days racing saves a lot of time/effort/money.
Looking at this from the other point of view though... The average cyclist can't buy an aluminium frame like those that Pantani rode, and even if they could, they'd be hideously expensive both to buy and also to continue replacing... The only alloy road frames they can buy will be those around 1.5kg upwards, and though they won't be terribly expensive, they aren't typically viewed as high performance products, even if 99% of the system performance is rider and only 1% bike... They can buy a 750g carbon frame for maybe £3k though, and it'll last years if looked after, as well as probably being more vertically compliant and laterally stiff (if designed to be) too...
The perception of all the frame materials' characteristics has come from experience by those in the know, with copious amounts of examples experienced. For sure, you can create an overly stiff steel or Titanium frame, or you can make a flexy noodle of a carbon or aluminium bike... You could make an extremely thin walled Ti bike that wouldn't last 1000 miles before fatiguing, or you could overbuild an aluminium frame to the point it wouldn't begin to fatigue even in a dozen lifetimes... I've owned many Hardtails and Road Bikes made out of each of the 4 main materials over the years (I'm discounting full suspension MTB's here for obvious reasons), and I can safely say that I have owned both good and bad examples of every single material... The long and the short of it is that everything is a compromise between weight, strength, stiffness, ride quality and price. But at the performance end of the market, it's very easy to understand why Carbon rules the roost these days, as it is generally significantly lighter with the only obvious downside being price...
I don't think it's the frame material so much as how it is used that makes a difference.
This in itself is a very key point to note... All materials have evolved from the era of lugged joints holding round tubes only, but arguably the advancements in Carbon and Aluminium frame manufacture have made the biggest difference in recent years to them being able to challenge the age old stereotypes...
I'm struggling to reconcile the articles above with the number of people who say steel just feels better to ride or who are absolutely in love with their titanium bike
Because that article is cherry picking to make the point that on a road bike the seat post is king when it comes to vertical compliance. Which is true for your arse. On the road or gravel. It doesn’t tell you anything about your other four contact points, or what happens off road, or look at anything other than vertical compliance.
This is worth reading.
https://www.sheldonbrown.com/frame-materials.html
One thing that @brant mentioned years ago on here was that the stiffness around the headtube junction is critical. With aluminium, you tend to have larger diameter tubes and larger weld areas, so that will tend to be stiffer than steel, ti, or many carbon frames. Mountain bikes that are going to be thrashed down rough descents and over big jumps will need a much stronger headtube junction than a road bike, so that's going to be much stiffer.
I have a carbon and an alloy Cannondale synapse. The biggest difference is the carbon one takes 32c tires compared to the alloy taking 25c.
I was quite disappointed a carbon framed, disk braked, Uber road bike was so similar to the aluminium one. Maybe if I raced it would make a difference, but over my longest ride of the year the difference in the time comes down to how much training I put in before it.
Same for the comfort. The tires make a noticeable difference. The carbon one came with 25c tires. Going to 30c then 32c with lower pressures made more difference than from alloy to carbon bikes.
11kg to 8kg is noticeable at the start of a ride but at the end they are both nice bikes.
I have a carbon and steel hardtail. Maybe the steel frame is a wee bit flexier. Maybe that comes down to the tires.
Next road bike will be the one that looks the best,
Also came across the following article, which argues that the perception of certain frame materials (particularly steel) feeling more comfortable is a placebo effect.
That article misses the point. It focusses on vertical flex which is minimal. Perception of 'comfort' in a frame in the way most riders describe it comes mostly from lateral flex, or twist. There is a fair bit of that in most frames and Steel and Ti frames (particularly old road frames) tend to have more of it than Alu.
He's right that seatposts and tyres make more difference to seated comfort, but that's more relevant on a road or touring bike when you're sat down most of the time. Riding off-road gives you a better impression of how a frame's stiffness overall gives an impression of harshness or comfort.
Carbon rules the roost these days, as it is generally significantly lighter with the only obvious downside being price...
And safety. Carbon is disproportionately represented in recalls and the mode of failure can be sudden + total.
The article only concedes one point which is that carbon may be better at vibration dampening for skinny tired bikes.
It can be, carbon is the only frame material that can actually dampen vibration. Bike reviews that talk about the 'damping' effect of steel or Ti are just mixing up terms or confusing flex with vibration reduction. Ti and steel make good springs, they flex without much energy loss, there is no damping.
Pantani’s Bianchi is a really bad example - they were notorious for breaking and the whole episode nearly sent Bianchi under as they strived to keep up with demand and the quality went south. The problem with aluminium alloys is that unlike steel, titanium and carbon they have a finite fatigue life. Consequently, they have to be over-engineered to compensate ie oversized tubes and welds which makes them stiff and unyielding.
When I used to road race I had a number of bikes, the lightest and stiffest was a carbon Bottechia with carbon wheels - it has absolutely no give that meant it skipped and hopped over any surface rougher than sandpaper - if you kicked on a climb the back wheel would skip, losing traction and you’d have to back-off. I much preferred my titanium/carbon Colnago as it handled far better.
No offence op, but you write like a chatbot. Even the username checks out 🙂.
Just to be sure, what am I showing in the above photos, and can you point out some very unique construction details?
The problem with aluminium alloys is that unlike steel, titanium and carbon they have a finite fatigue life.
Steel can suffer from fatigue too.
When I used to road race I had a number of bikes, the lightest and stiffest was a carbon Bottechia with carbon wheels - it has absolutely no give that meant it skipped and hopped over any surface rougher than sandpaper - if you kicked on a climb the back wheel would skip, losing traction and you’d have to back-off. I much preferred my titanium/carbon Colnago as it handled far better.
I've always thought that the human body does not interact with very rigid things well - tennis or squash, hockey, kayaks, windsurfers, bikes - the best products all have flex that works with us. But that's subjective and the difficult thing for mass production bikes is that flex is not frame size specific, a short rider may be more powerful than a tall rider and they my both weigh the same. So we've had this BS story going around that more stiffness is more better, but it needs to be optimised for the rider and use.
@jameso genuine question. I understand that lateral frame stiffness is very beatable between frames and that there is an intermediate amount of flex that feels right. But how does that flex contribute to comfort? Is it only in your corners? @mick_r is your radiator bike uncomfortable or hard to control or both?
A much better article on the stiffness thing is this one. There is also an article some where in the mag archive where they pointed a ti hard tail and i think a steel hardtail to look the same. They let loads of people ride them. Know one identified that one had the magic ti ride
https://www.slowtwitch.com/industry/thoughts-on-science-perception/
I've participated in numerous blind product studies over the years where we controlled bikes or the wheels (I've done this twice with a bike manufacturer during development work around a pro team, and many times with wheels) with fabric shield tensioned between seat post and stem, flat black rattle can paint on everything, etc. In each of these studies, the entire subject group including pro riders, engineers, and other industry people with LOTS of experience, struggled to find any real differences between any of the bikes, until after the study was de-blinded and everybody (including me) instantly began to try and rationalize it all… This is just human nature, we all do it, and from experience, it is nearly impossible NOT to do it.
One of the major discoveries was that after controlling for seat post (round post shimmed into aero frame so as to not give it away) not a single rider found the aero road bike to be less comfortable, less compliant, etc, than the identically setup 'endurance' or 'roubaix' bike (clearly this leaves room for the aero seat post to be why people feel aero bikes are less compliant..seatposts generally have more effect on bike compliance in the lab than frames do, but that's another story). We ran blind wheel tests a couple of times a year at Zipp to benchmark competitive wheels and our own prototypes, and we also found that blinded riders were generally unable to tell the difference between stiffness and inertia, had no reliable feedback on weight, lateral stiffness, or comfort in general, and in the end were generally only able to pick out the aero wheels because they were riding laps around a closed park environment using power, so the more observant ones would notice speed differences. In the end, we sort of determined that when riders didn't know what they 'should' feel, they really struggled to find differences in stiffness, compliance and weight between frames or wheels. The strongest correlation we ever saw was to tire pressure, but not in the way you would expect. Almost everybody assumed the setups with lower tire pressure to be the endurance bike and would then score it exactly as you would expect a magazine review of a comfort bike to look…so we determined that we all naturally would latch onto something we were confident in, in this case comfort, and then would proceed to perceive everything you expected from that bike: less aero, less stiff, better damping, etc. Imagine the shock for the group when it turned out that the it might have been a super stiff race bike, or an aero road bike! Let the rationalizing begin!
During the 303 Roubaix development, we broke the entire bicycle system into component stiffnesses to try and determine the relative contributions of things to ride quality. We were shocked to find that the entire difference between the special, longer wheelbase, layup optimized, cobble specific frame, and the standard road frame (which everybody could tell you was WAY too stiff to ride on the cobbles) equated to a whopping 4psi of tire pressure. Similar result with wheels, turns out that the 32 spoke box section Amrosio rims the teams swore by had about 50% higher vertical stiffness than the 303…yet the riders swore up and down that the 303 was 'too stiff' until we blinded them, at which point the opinions became nearly random with a slight bias toward the carbon wheel as more comfortable, yet with the riders preferring the carbon wheel only willing to proclaim it because they are all certain that it was the aluminum one.
Sure, carbon is repairable but my quote was more than a new frame.
@jamesogenuine question. I understand that lateral frame stiffness is very beatable between frames and that there is an intermediate amount of flex that feels right. But how does that flex contribute to comfort? Is it only in your corners?
I think it's about the perception of comfort as much as actual vertical give kind of comfort, because we vary in how well we perceive or seperate out inputs and cause/effect when we say a bike is one thing or another. The front triangle does have vertical give as well as lateral (or I should say torsional) flex, but it's rarely going to be 100% in one plane, it's more of a vector or combination. It'll happen more in corners yes, and a bike is rarely 100% upright with the rider only feeling vertical forces. More so on road rides or touring than off-road. So in the end though the vertical flex difference between bikes isn't a lot, it may well be related to the amount of front triangle flex and along with how rattly or soft the bike feels in corners, how much it flexes with you into and out of corners or when pedalling hard, it adds up to an overall perception.
FWIW in terms of straight-line feel over rough roads, the least comfortable bike I rode in recent years was steel and the most comfortable (by a large margin) was also steel. I also rate the V3 Arkose as one of the comfiest Al bikes I've ridden, that had some good flex. So whoever said above that it's more about design than material is spot on.
And I'm 100% behind the idea that seatpost flex is important for comfort. Many bikes should or could be more compact than they are to take advantage of this and seatpost material and size is worth paying attention to.
And I'm 100% behind the idea that seatpost flex is important for comfort. Many bikes should or could be more compact than they are to take advantage of this and seatpost material and size is worth paying attention to.
The D-shaped post on my Canyon gravel bike has incredible amounts of flex built into it. You don't really notice it when you're riding, it's only when you start leaning on it that you can see how much it'll give.
Fascinating link to the Slowtwitch article, I've often wondered if there's been any of that "blind" testing (noting of course how difficult it it to do truly blind on a bike!). Related to that, there was a story from Willy Voet (the masseur behind the Festina EPO scandal) about how Richard Virenque had massively pissed him off one day so instead of administering his drugs directly, the masseur had simply thrown him the bottles and said "sort yourself out". Next day Virenque was on a flyer, won the stage and he went to WV, hugged him, apologised for his behaviour the previous day, thanked him for the amazing concoction he'd given him and so on.
The bottles had contained saline solution, no drugs at all.
That Slowtwitch article comes to similar conclusions as others along those lines. Most of us don't pick up on subtle differences that well - a few are very perceptive and more are not very perceptive at all. I think we notice differences more when we're able to challenge our muscle memory by riding something for a good number of hours (25+ to adapt to a new bike imo) and adapting, then making a change. Back to back laps don't allow for as much of that adaptation as we're still in the perception-reaction-adjustment stage.
I’m certain the seat post thing is what got this started. Back in the day when we all ran our tyres at 30 psi or more a good friend bought an early aluminium orange hard tail with a seat post fatter than anything we’d seen before. Sat down you could feel every ripple in the tarmac. Every magazine was telling us aluminium is harsh.
A few years later i bought basically the same frame with with a 27.2mm seat post and it was just like steel bike it replaced in terms of seated comfort
As Ampthill knows, I run an unfashionably (72 degrees ish effective) slack seat angle, and it is amplified by the bent seat tube, which is vertical at the bb and 67 degrees at the top. So the 27.2 seatpost is in more bending than normal - deliberate as I'm a lightweight and want the flex.
The biggest difference in feel on the radiator bike is it is probably more torsionally stiff at the front end. It really does just ride like a slightly heavy and numb bike.
If that is a photo of a broken Liberty Ship, then our materials lecturer always used it as an example of low temperature brittle fractur
The D-shaped post on my Canyon gravel bike has incredible amounts of flex built into it. You don't really notice it when you're riding, it's only when you start leaning on it that you can see how much it'll give.
Canyon have developed many great seatposts over recent years. They have some now that can be retrofitted to most road/gravel bikes. Highly recommend one. A comfortable seatpost won’t make any difference to how my mountain bike feels on the descents though.
... fracture of continuously welded steel structures initiating at a triaxial stress concentration. Apologies for the crappy combination of this forum and my phone 🙂.
Oh, as an aside, Canyon did the same for drop bars as well… but it looked odd… people would rather add heavy suspension forks or a nodding donkey stem then have odd looking double decker bars it seems.
I'm not super impressed by the suggestion that AL is the king of frame materials, and that's based on engineering and practical experience.
The bendiest bike I've ever seen was a friends old school Al guerciotti. It was hideous, not helped by the frame gate frames size and you could see the bike bending as he road it. He saif he could feel it as well, and it wasn't confidence inspiring to ride. To get round this Al needs to be oversized, and you then need to cross the bridge then that Al based alloys are mechanically soft and fatigue cracking is a very real thing. Crack'n'fail was a joke made on experience in the 90's, and while it's better now it hasn't gone away and the fix is to overbuild frames as much as poss. But ignoring the shorter lifespan of Al frames is putting your head in the sand
So in terms of frame lifespan my experience is that it's Al -> steel -> carbon worst to first and I'm keeping Ti out as it's so reliant on quality of manufacture. In that it also means that Al is bad ecologically as you need to replace frames and while it's possible to recycle Al frames, I don't know who's actually living the dream.
The article dealt a lot with vertical compliance, fair 'nuff. But the Guerciotti also displayed an alarming degree of horizontal compliance. So you're back to oversizing to fix that as well. And that impacts comfort as well.
Personally the most uncomfortable bikes I've owned have been Al and I'm looking at my current BMC Team Elite hardtail commuter here ;.-( My carbon bikes have been much more comfortable. I do wonder if that's becauise I'm short, and the rear triangle is very compact, limiting flex. I don't care if that mans testing says I can't feel it, my backside can.
A much better article on the stiffness thing is this one. There is also an article some where in the mag archive where they pointed a ti hard tail and i think a steel hardtail to look the same.
I currently have a carbon road bike and an all track bike. Using same tyres I cannot feel any difference when riding them - both feel very stiff when climbing out of the saddle, with absorb bad roads in same way etc,.
Until recently I also had a late 80's Columbus SLX frame and it felt shit compared to my all and carbon bikes. Seemed to just not respond when accelerating or climbing (not just down to weight) and didn't feel any more comfortable.
If that is a photo of a broken Liberty Ship, then our materials lecturer always used it as an example of low temperature brittle fractur
It was a tanker, not a Liberty ship, but basically the same problem. Point is that steel is not automatically immune to fatigue, plenty of steel structures crack and fail.
Later research indicated that the failure method was probably abrittle fracture, caused by low-grade steel. This would become highly brittle in cold weather, exacerbating any existing faults and becoming much more liable to fracture.[3][4]
https://en.wikipedia.org/wiki/SS_Schenectady#Hull_fracture
GCN video just out today on an old titanium road bike (actually from Team Festina which I referenced earlier - coincidence!)
They test it against a modern titanium bike (a Sturdy Cycles one) and a modern carbon bike.
Seat tube angle on the old bike looks very weird!
I've got a carbon road bike, and it feels nicer to ride than my old alu road bike. So carbon is definitely better than alu for road bikes. Fact!
I've never had a carbon MTB, but my steel ones feel better and more funerer than the alu ones I've had in the past. So steel is best for mtb's. Fact.
Therefore IME alu is the worst frame material for either road bikes or mtb's*.
Hopefully that sorts out and confusion for people still wondering.....
*Unless I buy an alu one and it's better than the others....
To the person who has never broken a steel frame, you have not ridden far enough.
my last two commuter frames, Surly Ogre and Kona Unit have both broken frames.
This was after 10 years each and 30000 to 40000 miles each in alll weathers.
I think one reason steel frames can feel comfier than aluminium frames, even when built to have similar stiffness, is that the denser material lowers the resonant frequencies and takes those vibrations into a range that are generally less unpleasant for humans.
Then add in the potential for making a frame that is strong enough to have a long life without fatigue failure whilst making it less stiff (through smaller diameter tubes) and steel gains again vs aluminium.
Yes, vertical compliance is minimal (but not zero!) in a diamond bike frame but we ride bikes in 3D - and as someone who doesn’t ride road or gravel bikes and has his saddle dropped as much as it’s up, I care far more about the standing handling of a bike, particularly in flat rough turns where the grip is critical. My current steel hardtail is stiff and strong enough to take a 170mm 29” fork but feels smoother than my previous alloy hardtail which was only rated to handle a fork 40mm shorter.
In my mind the argument goes:
There's not enough performance difference between them to justify the price, even if the prices are close.
You'd save more weight, be more comfortable, and be more aero spending the money on wheels, group set and finishing kit.
We also know that in the real world the performance difference between Red and Claris is negligable.
Which is why there's always some 17yr old kid on an 16speed Carrera embarrassing people on the chain gang, none of it actually matters, it's all down to the rider and as someone said you may as well just buy the bike that makes you want to go out to the shed and ride it.
the perception of certain frame materials (particularly steel) feeling more comfortable is a placebo effect. Almost all compliance comes from the tyres and seatpost,
Yep definitely.
My Ti frame felt remarkably uncomfortable until I swapped my preferred saddle and highly compliant seatpost. Same applies to the front end, the handlebars and stem are flexing more than anything else.
one reason steel frames can feel comfier than aluminium frames, even when built to have similar stiffness, is that the denser material lowers the resonant frequencies and takes those vibrations into a range that are generally less unpleasant for humans.
Also this. Although it varies between frames as much as it does material. Some steel frames feel really dead. I wonder if it's to do with the shape of the tubes Vs stiffness of the wall section, does a thick tube with thin walls give a regressive curve and a thin tube with stiff walls a progressive one? The former might feel snappy and the latter compliant even if the deflection is overall the same?
To the person who has never broken a steel frame, you have not ridden far enough.
my last two commuter frames, Surly Ogre and Kona Unit have both broken frames.
This was after 10 years each and 30000 to 40000 miles each in alll weathers
That’s some distance! Sort of proves the point.
You can make frames that feel and ride differently using the same material differently, let alone a different material. Honestly I'd challenge <anyone> to ride a mk1 soul, a mk1 bfe and a mk1 Soda and not notice differences, as a perfect example. 2 steel and 1 ti and all noticably different. Or a mk1 Scandal and a later one, both an aluminium alloy. Or an old Orange and a newer one with the revised swingarms, my 224's rear end was so flexible it'd rub the tyre if you cornered it hard. Not because of the material, because Orange made a bendy alu bike.
Or my gen 1 Mmmbop. I rode a Ragley Ti, loved it, superb geometry and it just felt great to ride, proper masterpiece. Got an Mmmbop expecting it to be similiar, never really liked it. It wasn't comfort- I have a cast iron arse- it was noticably worse for grip and composure on rough stuff, the rear end simply bounced off more stuff, skimmed and skipped more at speed, every so often would take a bigger kick off a root or rock and was just generally unsettled and less managable when ridden hard. Braking bumps, urrgh.
So i reluctantly bought myself a Ti, which I couldn't really afford, transferred every single part over, and that problem instantly went away (before someone says "it's your tyres"). Not a sunk cost thing obviously since I very much wanted that £150 Mmmbop to do the job!
That wasn't titanium vs aluminium of course, that was "this is a brutally stiff frame" vs "this is less stiff".
So i reluctantly bought myself a Ti, which I couldn't really afford
And I still don't feel guilty 😂
genesis alpitude 26 853 - broke seatube
inbred 26 853 broke headtube from frame.
orange p7 26 653(?) cracked chainstay.
chameleon ally 26 - no probs in 3 years
chameleon ally 29, cracked dropout (problem waiting to happen/poor design)
chameleon ally 29 - 3/-4 years in w/o issue.
specialised chisel HT frame is ~ 1500g in large and known for comfort.
ally frames IME transmit more high frequency vibration than steel but otherwise behave very similarly.
Said this many times
handling = geometry
stiffness = tube diameter
weight = material
i have an alloy and an ultra light carbon Defy. They handle exactly the same. I like titanium because it has the stiffness of steel and the weight of aluminium. Making aluminium too thin causes cracks, welding titanium badly also causes cracks. Carbon frames get thrown away out of the mould.
the best frame material is the one that makea you smile moat.
I own/have owned bikes of all the major materials, aluminium, carbon fibre, titanium, steel.
I kinda reckon carbon's the smart choice - it's more repairable, it's more shape-able (especially road bikes, if you care about aero, but mountain bikes too for weirdo suspension designs), compliance can be tuned much more than other materials, it's normally lighter, and it's often cheaper than titanium or high-end steel.
I reckon for cracking, alu is the worst of the lot - not because it's more prone to breaking than anything else, but because when it does, it tends to do so more catastrophically and with less warning. I think both ti and steel will bend before they break, and carbon tends to fracture - alu lets go all at once.
stiffness = tube diameter
weight = material
Wee bit reductive though? Since tube diameter is also so closely tied to material, and construction can make a big difference to stiffness even with same thickness tubes. Like, just flattening and ovalising a tube changes its stiffness in different directions
And I still don't feel guilty 😂
Well I mean how DARE you lend your titanium superbike to a complete internet rando, you should be ashamed 🙂
Now I think people should buy whatever bike they want, or whatever gets you out riding. One point I will agree with is that carbon, titanium, and steel bikes can all be aesthetically lovely in ways that alu bikes are usually not.
this is the key point. The cycling industry is a fashion industry. If it wasn't stuff wouldn't be sold in different colours each year People will generally make aesthetic choices first then cherrypick factoids from the marketing bumpf to make those choices seem somehow engineering or performance based, but they'll do that after they've made their choice based on looks. You'll see more commentary on this forum about how any bike / frame / component looks than anything else
A lot of the resistance to change in the ever evolving 'standards' grumbles I think is rooted in worry that a new diameter or a new set of angles is going to make your current bike look unfashionable.
i have a ti mtb that is very harsh and stiff.
itsmuch more about the design than the materials
What happened to the OP? He wanted to discuss this then buggers off after the original post and one comment.
What happened to the OP? He wanted to discuss this then buggers off after the original post and one comment.
By "bugger off" you mean not replying for one day while replies are still rolling in and I'm having a busy Sunday? Not sure what your problem is.
Apologies OP but it is just unusual to start a fairly detailed discussion post and then not communicate thereafter.
From the handful of users I know you've drawn in people from bike manufacturers, frame designers, framebuilders, engineers and physicists. But I'm still not sure if you've got more than opinion and anecdote.
Apologies OP but it is just unusual to start a fairly detailed discussion post and then not communicate thereafter.
Which might be fair to say if I hadn't replied for a week. This is a forum not a live chat.
From the handful of users I know you've drawn in people from bike manufacturers, frame designers, framebuilders, engineers and physicists. But I'm still not sure if you've got more than opinion and anecdote.
Yes and I like the range of perspectives from people with far more experience than me. You seem to assume that I made up my mind after reading that cyclingabout article. Many commentors have brought up flaws or other points that article and my first post has overlooked. Which I have enjoyed reading, what I don't enjoy is meta commentary that brings no substance to the discussion.
I think one reason steel frames can feel comfier than aluminium frames, even when built to have similar stiffness, is that the denser material lowers the resonant frequencies and takes those vibrations into a range that are generally less unpleasant for humans.
This and the sound fit with my experience. Steel and Al hardtails on rough ground may be objectively the same stiffness; however, the Al is noisy while the steel is silent. Perhaps the bigger internal volume of the Al, or the different density. Either way, I perceive the steel as being different, and, as mentioned, in some of the articles linked above, we humans are not great at correctly identifying what the actual difference is. Also, I like steel frames.😀
The main theme I'm seeing from the responses is that it's not about the frame material, it's how its used. Interesting to hear many reports of bikes whose ride quality does not match the stereotype, like uncomfortable steel bikes.
That suggests for the next bike I should look for a specific frame which everyone loves the ride quality of, and is remarkable in its design/QA/aesthetics, rather than caring about the material.
I also learned:
- Comfort is about torsional compliance not just horizontal compliance
- The Pantani record does not tell us much since he was riding a very unique alu frame
- A Silca bike tester confirms that the placebo effect is huge for frames
- A downside of aluminium is that frames have a finite lifespan and failure can be sudden
The main theme I'm seeing from the responses is that it's not about the frame material, it's how its used.
Absolutely. But how the material can/might/should/could/will be used depends on its characteristics.
"Steel and Al hardtails on rough ground may be objectively the same stiffness; however, the Al is noisy while the steel is silent. Perhaps the bigger internal volume of the Al, or the different density."
Aha, I think you've hit upon something there!
The steel tubes are denser and slimmer - this lowers their resonant frequencies according. The air chambers within the steel frame are smaller which raises their resonant frequencies (they'll exhibit these as a mix of half and quarter wave resonators and helmholtz resonators). If you think of the internal volume compared to an acoustic guitar body it's a small volume. I suspect that with a steel frame the resonant frequencies in the metal are a long way from the resonant frequencies in the internal air, whilst in an aluminium frame the resonances are closer so they're more easily excited. And that's that annoying buzz.
Also the bigger and less dense aluminium tubes will emit more sound due to the greater radiating area and the reduced acoustic impedance mismatch vs steel. A quieter bike simply feels better downhill, you hear more of what your tyres are telling you about the ground.
Apologies OP but it is just unusual to start a fairly detailed discussion post and then not communicate thereafter.
Better than the alternative;
Ask a "question"
Belligerently argue with absolutely every answer because what you really wanted was validation of your starting premise, not alternative viewpoints.
The steel tubes are denser and slimmer - this lowers their resonant frequencies according.
Surely this comes back to what Cy said about the Rocket, on a bike your design is already size constrained, your seat-tube and stays are always near enough the same sizes regardless of material because that's what fits.
Comparisons to sound waves isn't valid I don't think. My SS'ed (alu) HT has a chain tensioner on the BB which makes a noise (I'm guessing a resonant frequency of the downtube must be close to the chain passing over it) yet it's actually possibly the most comfortable HT I've had.
Secondly, and related, tubes aren't absorbing these impacts/vibrations in compression, they are WAY too stiff for that. They do it by deflecting, so anything that bends them or makes them thinner in the direction you want to deflect them helps. Traditionally that would mean hourglass or wishbone stays, now it's more likley a flat top tube.
The Pantani record does not tell us much since he was riding a very unique alu frame doped up to the eyeballs?
FTFY ;o)
I'd say steel over Alu every time, if only on silence/longevity/reparability grounds. The weight isn't really important unless you need to save the grams for racing.
I wouldn't choose to have an alloy or steel frame at all and I've had quite a few of both. The only really well riding (handling/comfort) steel frame I've had was an Independent Fabrication and the only alloy one (that again had both handling and comfort) was a Klein. I've had steel and alloy bikes (Santa Cruz, Salsa, Orange, Genesis, etc) that all handled well, but weren't stand out for "feel". The Klein and the IF both had that unique combination of material and tube shape/size, possibly suggesting that design which incorporates the junctions, tube cross sections and material performance in the centre and the joints is the key.
Like, just flattening and ovalising a tube changes its stiffness in different directions
You confirmed my point. That all things being equal (i.e., geometry), stiffness can be changed by tube cross section. My Enigma has an ovalised oversize down tube, for example. But i don't have a round version Echo to compare. I'd summarise Ti by: If you like how steel handles, you'll really like Ti. If you don't (more flexible frame), you'll prefer alloy and carbon. The oversize carbon really stiffens up a frame and delivers low weight without trying.
But weight balance is geometry, as is fork rake and trail, wheelbase, BB drop, all solved problems and largely not deviating much from 73 degrees parallel on the road (a few tweaks of half a degree on seat and head tube and sometimes longer seatstays). As I said, I have a bargain basement alloy, and a pro-level carbon Defy SL.They really do ride the same (same contact points and stem, same geometry, 10x different price point). I am under no illusions that my Charge Freezer Ti would handle the same as the steel version, and that my Brompton T-Line handles the same as an P-line.
There are many choices in frame design, but I think my simple reduction holds. Go and ride a Vitus 979 (*swoon*) or an original Carbon Giant Cadex 980. Nobody was claiming stiffness for Aluminium or Carbon, it was all about frame weight for first interations of new fangled materials.