Steel Full Suspension Bikes

https://www.google.co.uk/search?q=all+steel+bicycle+raleigh+lion&rlz=1C1WPZA_enGB817GB817&tbm=isch&source=iu&ictx=1&fir=QqDpkuwtT60JsM%253A%252CMqw9l2AxLONC6M%252C_&usg=AI4_-kSDu53J17gBgnsap9YHZ6RipE-oXQ&sa=X&ved=2ahUKEwiRwI_6x_HdAhWOHsAKHanFDPcQ9QEwAnoECAYQCA#imgrc=QqDpkuwtT60JsM:

I grew up riding steel hardtails, originally fully rigid and then at great expense with an RS-1 fork. I like the look of a steel frame, it just looks right to me. And I love the way it goes “ping” with small stone strikes. That’s enough for me to want to keep buying them.

Have a poke through the “geek” section of the Cotic website – Cy did a good article about why he decided to use steel. Largely about being able to tie the BB and the pivot locations together in a solid fashion.

From that link.

One of the key things I wanted to improve on from the Hemlock was the stiffness of the connection between the front and rear ends, so I started with the seat tube as it’s where all the suspension pivots would be hanging from. This would be critical.

So the designer of the bike says he doesn’t want it to flex. I think that’s pretty much settled it.

From the KTM link above:

Cold forming and the use of high-strength steel gives the profiles extremely high strength, making them three times as stable as aluminum. As a result, a much thinner chassis can be produced and the weight difference between the two materials can be compensated.

A key advantage of the steel chassis can be found in high-performance sport: MotoGP requires that each race bike be precisely adjusted to the seat position and angle of the driver. This can be done much more quickly with steel thanks to the faster work processes and its excellent workability, saving valuable time.

So, easier to modify the frame at a race, and stronger and more stable.

Hols2 the reason bike engineers want stiffness at the linkage is so that the flex at the linkage doesnt cause the shock to bind. Almost all bike engineers design flex/compliance into frames. If you don’t think compliance makes a difference go run your tyres at 50psi and see how that feels….

The mighty Honda Racing Corporation think in a similar way to you hols – all theory and no experience. When HRC were developing their all conquering RCV MotoGP bike (after the rules changed to allow 4 stroke engines) they produced a bike that according to all their data and testing would be the fasest bestest bike they could make. Test riders loved it and sung it’s praises. When the actual factory riders test the bikes they could really gel with the bikes. They were so stiff that at race pace (something the test riders could replicate consistently) that they felt vague, with the front wheel chattering and the riders lost confidence and lap times suffered. Those HRC boffins scratched their massive heads…but the data says etc… It wasn’t until a certain Mr Rossi (other riders had asked for this too, but only he had the clout at make the engineers even try contemplate doing it) wanted them to make the frame less stiff – engineered flex if you will. Even though on paper it would make the bikes slower it gave the riders a better feeling of what the bike was doing underneath them. They could push harder into and out of corners and the laps times tumbled.

Feeling isn’t something that an engineer understands

If you don’t think compliance makes a difference go run your tyres at 50psi and see how that feels….

What I said earlier, if you bother to read the thread:

this will be an order of magnitude smaller than the flex in the tyre

It doesn’t matter whether your frame is made up of tubes, layers, or castings… a team of people (engineers AND riders) with far more experience and knowledge than “you” (not all of you) will have designed in a different balance of weight, stiffness, thickness etc all over the frame. What they require at shock mounting points and pivots will differ to what they require of the top tube, for example.

Euro – a MotoGP bike (and an F1 car) are very different to MTBs and moto-X bikes. They run on extremely smooth circuits so they have very short suspension travel and very stiff springs.

Moto-X bikes, DH and Enduro MTBs, and rally cars run on extremely rough terrain so they have much longer suspension travel and much softer spring rates. The point isn’t that steel frames don’t have nice resonance properties that riders can detect, it’s that when you have a 6″ travel bike hammering over rocks and roots with big fat tyres at low pressure, the tiny bit of compliance that comes from the frame flexing will make no measurable difference to helping the tyre track the ground.

So we’re down to the difference between “measurable” and “feel”. Which is why actually riding prototype bikes is important when developing a new one. It also why demoing a bike is so often more useful than looking at the numbers when buying one. The whole “steel” element of this thread is a bit of a red herring… all good frames will be designed with these concerns over where to build in more/less stiffness in mind, whether it’s made from tubes, layers or castings (or a combination of all three).

Nice stealth edit kelvin.

Yeah, I realised that simply saying you are “wrong” was unhelpful.

Have a nice day.

Obviously to much flex is a bad thing, but so is completely rigid, Honda made such a mistake with the 1997 CR250 the worlds first alloy framed production MX bike.

In 1996 the MX press could not wait to get their hands on the all-new machine. Early tests sugarcoated the bike somewhat, calling its ridiculously ridged chassis “pro oriented” and awesome for Supercross. In reality, the Honda was an overbuilt beast that transmitted every pebble on the track directly to the rider’s hands. Honda made certain the alloy frame was not going to break, but they ruined the rest of the bike in the process. The beefy frame acted like a big tuning fork, funneling every ounce of vibration from the motor right up through the CR’s handlebars. On hardpack soil the CR was unsettled and never felt firmly planted to the track. In deep loam, the bike performed better and felt more at home. Turning was typical mid-nineties Honda, sharp in the tight sections and nervous at speed. In addition to being unforgiving, the harsh frame gave the bike a “dead” feel in the bumps. Instead of floating over obstacles, the  “97 CR250R “thudded” through them. The CR’s chassis may have looked high tech, but its performance was strictly mid-evil in ’97.

But with all that I reckon Cotic chose steel because thats what they do, make steel mountain bikes. (For the most part)

Kelvin, what would be really useful is if you could share all the notes you made while comparing different prototype bikes and demoing production bikes. It would be much better than relying on journalist’s reviews.

Honda made such a mistake with the 1997 CR250 the worlds first alloy framed production MX bike.

So did they stop using aluminium?

share all the notes

I’m a very average rider. My notes would be something like “whoop” or “woah”…of little use to anyone.

Feel free to talk to Cy, Paul, Chay, Rich and the Swinnys anytime you want about it, but you’ll need a different approach to the one you’re using here if you want a decent conversation about anything.

Why not try riding some more bikes yourself?

So did they stop using aluminium?

The material is irrelevant. Designing in different stiffness characteristics is a vital part of what they do, no matter what the material. Keep claiming that ultimate stiffness all around is now the only goal, and keep being wrong.

The material is irrelevant.

I’ve had carbon, aluminium and steel FS bikes. There’s something about my Rocket 275 that just *feels* better… can’t really put my finger on it, but it’s definitely down to the material

He has a preference. Bikes made with other materials (and note that other materials are used for that frame anyway, i.e. for the swingarm) are still designed, and manufactured, to have different stiffness characteristics across the frame. Everyone is looking to design in the “feel” that you argue doesn’t matter. Perhaps it doesn’t for you. Have Cotic done a good job of this, using mostly steel? I’d say absobloodylutely! But I’m biased, so listen to others, not me. Or try for yourself.

So did they stop using aluminium?

No, they never went back to steel. Just refined their alloy frames up untill today. The quote was just to illustrate how a bit of flex is a good thing. Compliant frames can be made out of most materials. So can overly stiff ones. Steel as a material does have some inherent characteristics, Cotic as a maker if steel frames obviously use this as a marketing tool.

At they end of the day just about everyone who’s riden one thinks their very good bikes, and material aside thats all that matters 😎😎

Euro – a MotoGP bike (and an F1 car) are very different to MTBs and moto-X bikes. They run on extremely smooth circuits so they have very short suspension travel and very stiff springs.

MotoGP bikes have roughly the same travel as road motorbikes, around 130mm fork travel. You think hitting rumble strips at 200mph is smooth? Nope! F1 cars do have very stiff suspensionbut the large tyre sidewalls add a huge amount of compliance and extra suspension.

Everyone must have seen at least one slowmo video when an MTB wheel flexes sideways, then grips, then flexes, and so on? A bit of flex is a good thing, add it all up from the tyre sidewall, wheel, rear triangle, front triangle, forks, and so on. So thinking there’s no flex in a bike isn’t right, frame material will just add to that flex.

Anyway, one of the main appeals of steel for me is durability. My life goal is to have a lightish trail/light enduro FS bike in carbon, a titanium hardtail, and a steel (coil sprung) gnarpoon for the gnar. If the steel bike gets a few boulder strikes to the frame I’d hope it would shrug them off whereas a carbon frame would likely be toast.

steel is useful for low volume manufacturing primarily. nothing wrong with that. if vendors want to use a bit of artistic licence and make a virtue of it, why not? and of course some do prefer the asthetic and the arguably better damping of higher frequencies that steel frames exhibit (IME on hardtails).

funny how all these compliant rear ends are these days fitted with bolt-through axles, to stiffen things up, and cotic chose ally as the rear end on it’s latest fs bike. the steel front end being built here, and that ally rear end being built in taiwan, is also probably coincidence?

<div class=”bbp-reply-author”>mickmcd
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am sure arian ward once sent me a photo of a GP1 motorcycle that had had the yokes modified to allow them to flex in the corners

The SP1 is the most famous example- the first road motorbike ever made that was problematically too stiff, after decades of rubber frames. Eventually the problem was reduced with a redesigned swingarm designed to flex but til that came along, Honda racers and engineers variously machined bits out of the frame and swingarm, tuned down pivot bolts, or if they were on a budget just left some of the frame bolts loose.

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Nico Vooleywoo spends ages modifying proto Lapierre frames in his workshop in much the same way. I don’t know if he’s been to convent school
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I’ve ridden bikes that were too stiff for me- had a Ragley Ti and a Ragley Mmmbop with literally the exact same components and the difference in traction was completely unmissable. But not everyone’d like it, some people like stiff and that’s fine too. Obviously not a full suss, don’t care. I think of it as smear, it feels a better word for me.

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Incidentally hols2 it’s totally possible to have the pivots and other moving part relationships stiff but have flex elsewhere. That’s what Honda did with their reengineered bike, I haven’t a clue if it’s what Starling and Cotic do but it’s obviously feasible to have, say, the BB and seattube and linkage be stiff but the long arms of the swingarm be softer.

Incidentally hols2 it’s totally possible to have the pivots and other moving part relationships stiff but have flex elsewhere.

Even if you choose to ignore “feel” and just want the frame to be a sensible weight, then you’ll probably end up with this combination anyway.

So the designer of the bike says he doesn’t want it to flex. I think that’s pretty much settled it.

I suggest you read all the article, not just part of it. Correct, he didn’t want the pivot to flex, hence using steel as Vs alloy it’s much stiffer. However…

For all this talk of maintaining stiffness in the frames, this was – and still is – mainly concerned with the seat tube area of the bike. Making sure the front is tied to the rear solidly. Despite the strength and durability advantages of our Reynolds 853 top and down tubes compared to other materials, they aren’t as stiff. However, the more I’ve ridden our bikes, and the more feedback I’ve got from testers, owners and journalists, the more I’ve come to realise that the famous ‘steel feel’ is just as obvious and advantageous in suspension bikes as it is on hardtails.

What the top and down tubes allow the bike to do is twist a little along it’s length. Top tubes in particular are very much the defining feature of the ride character of a bike, and bike to flex just a little bit along it’s length as you cover rough terrain is a huge advantage in terms of traction and confidence. It’s what makes good steel hardtails feel so great, and I love the term ‘breathing with the trail’. Instead of “Stiffer is better. MORE STIFF”, let the bike give a little across those bumps. This is especially true on cambers where the hits are no longer in line with the suspension movement. The ability of the bike to mould itself to the terrain instead of being pinged off the line is a great trait of a steel bike – whether it has springs or not!

Oh look, he also wants flex in other areas of the bike not the pivot area.

And to back up everything everyone has been saying about the MotoGP analogy and bumps when cornering:

A great analogy comes from MotoGP. These guys get over to crazy lean angles, and at those angles, if you hit a bump the suspension won’t absorb it – the force is going at 40 degrees to the suspension movement plane. A few years ago, the ‘stiffer is better’ mentality got into the bikes, and Ducati in particular built a carbon chassis bike with the engine as a stressed member, with incredible stiffness. And it was borderline unridable, because it had hardly any grip at all when angled over in the corners, and they couldn’t change the engine block to tune the stiffness. They eventually went back to a fabricated metal frame where they could tune the stiffness/flex more easily and become considerably more competitive. It’s the same on a smaller scale with mountain bikes: We corner with some fairly large angles on the bike, across rough ground with bump forces going nowhere near the plane of the suspension movement.

You forgot the mic drop.

😀

I love the term ‘breathing with the trail’.

Yes, that is some brilliant marketing BS. Love it.

https://singletrackworld.com/forum/topic/steel-bikes-going-against-the-curve/page/3/

But with all that I reckon Cotic chose steel because thats what they do, make steel mountain bikes.

This. It’s a selling point that differentiates them from the majority of the competition. Whether it’s better or worse is largely irrelevant given that most decent bikes these days are more capable than their riders.

OP, I absolutely love my Flaremax, easily the best bike I’ve owned, remarkably lively feel to it and I’m still surprised how much steel spring I can feel even with suspension – I’ve owned a few lovely steel hardtails and the Flaremax has it too. Get one I say.

Hols2, I leant it over round a corner and when I looked back, I could literally see it complying with the ground. Literally.

One of the best cornering bikes I’ve ever owned was my Cannondale Prophet ‘enduro’ project that I posted about on here. It flexed to buggery but carved long fast corners like nothing I’ve had since.

I think Cotic’s flex/rotate around the seat tube but the swinglink protects the shock from loads.

Lots of TL;DR stuff here about frame materials. All I know is a demo’d a flare (non max) a couple of years back and I absolutely loved it. Unbelievably capable bike and within a few minutes encouraged me to attack descents super quick.

hols2, yes I’ve got a **** mech eng degree. And if you were a good engineer you’d have the wisdom to know that details matter, especially when optimising products where races are lost by fractions of a second.

Make a bike stiff around the pivots and stanchions so the bearings and bushings move freely, even when heavily torsionally loaded. Don’t make the head tube to BB connection so stiff that it jitters and skips in the turns.

It’s not just me saying this. And it’s not just steel frame builders. Every well designed alloy and carbon has had time put in during R&D to get the right balance of stiffness. Some of the recent Norco frames now use lighter gauge tubing in smaller sizes to stop them being too stiff.

And it’s the same with wheels – ultra stiff carbon rims are being found to be less fast down a rough trail. If all that matters is tyre and suspension compliance no one would be putting work into making wheels with the right amount of give.

Before I bought my race bike a test rode the ali version, to check the geometry. Bought the carbon version (too hard to get hold of to test ride)

There was a lot more lateral flex in the ali frame than the carbon one (as alarming demonstrated by a friend twisting it with his hands, his ali one visibly flexed, my carbon one didn’t) Could I feel this when riding? A wee bit, but I suspect that this was at least in part because I was expecting to feel it. In a (very dangerous) blind test I suspect I would not have noticed Did it feel different to ride? Yes, but that was down to being over a pound lighter. rather than flex. Different materials did feel different for me on as much of a like-for-like basis as I could get.

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Studied finance and commercial real estate at university of Reading so eminently qualified to comment.

Does the fact that the Cotic FS bikes have an alloy, not steel, rear end have any bearing on this sciencefest of a thread?

Does the fact that the Cotic FS bikes have an alloy, not steel, rear end have any bearing on this sciencefest of a thread?

Of course not. The springy steel top tube lets the bike “breathe with the trail”, the superstiff aluminium swingarm provides 28.3% more stiffness so that the tuned carbonfiber rim will flex to the optimal amount to provide synergy with the custom shock tune. Don’t think of it as a bike, it’s really a poem on wheels (if you’re exactly the right weight, fat or skinny people need not apply).

has anyone ever tested to see if a motorcross bike is faster than a pushbike

Moto-X bikes seem to breath with the trail better than pushbikes.

https://youtu.be/i2EL9GFQy5s?t=41

Dear god that got pretty boring, pretty quick!

Thanks for the in put chaps but all I really wanted to know was if the weight burden of a steel FS was worth it in terms of ride and performance in the ‘real world’.

Im not a nuclear scientist and I’m not interested in the properties of this or that as too be really honest I just ride bikes – some I can’t get to test easily so before I put in the effort of sourcing one or two I thought I’d ask.

Thanks though 🙂

after that conclusive test it’s obvious

a crosser is cheaper

a crosser is faster

i know cheekying cutgate is going to have ebikers **** raging …

im done with pushirons

I don’t think the weight penalty is that big if you compare a like for like bike. Carbon is generally lighter, but often aluminium FS bikes aren’t.

I’m not convinced that it’s a super material, if it was then surely all of the big manufucters would be making their race bikes out of it. But it does look cool, and as others have mentioned, it’s easier for small manucfucturers to work with in small quantities.

Surely it would be quite easy for someone to do a test to prove what impact different frame material has on a bike. I’m surprised no one has done it, or if they have, I’m surprised no one is linking to it. I’m a big fan of a lot of the steel frame builders, but I’m not sure they’re in the best position to give a balanced view.