Why Aluminum, Not Steel?

[Alex Dark]

I would have to agree, the goal for frames is to make them pretty stiff, no-one likes a flexy frame. I've ridden both Steel and Alloy frames and I can't really say I can tell the difference just from material alone, I have ridden a Ti frame before and I could tell the difference with that, mainly because it had a shite chainstay yolk design and was as flexy as a wet noodle.

Bit O/T but was that the Global Ti frame proto? Seem to remember it being in MBUK a few years back

[Ali C]

yes, yes it was

[Filo]

I agree that you can't really tell the difference,I just like the look of smaller tubes and smaller welds

[Al_Fel]

Look at TRA's new video and tell me Alu isn't good enough haha.

[clerictgm]

Look at TRA's new video and tell me Alu isn't good enough haha.

I think he snapped several HEXes. It can't be ONE frame for all this time.

[rocky111]

It's all about shape strength alu is half as strong as steel, but also half as light, so they can make it twice as thick, and the fact that it's twice as thick makes it strong. It's not really that important weather it's steel ali or ti it's how well the frames made, if there are stresses in the metal or weak joints any frame will crack.

[eskimo]

There's allot of ongoing debate on this in many diciplines still, not just trials.

Though myself prefer decent chromo.

[Mark W]

I think he snapped several HEXes. It can't be ONE frame for all this time.

Is that actually based on anything?

[Martin Reynolds]

It's all about shape strength alu is half as strong as steel, but also half as light, so they can make it twice as thick, and the fact that it's twice as thick makes it strong. It's not really that important weather it's steel ali or ti it's how well the frames made, if there are stresses in the metal or weak joints any frame will crack.

Your saying its half the weight, so you use twice the amount?

From your logic, both frames would weigh the same, and be as strong as each other

[FamilyBiker]

weather it's steel ali or ti it's

rain,good rider and yes,i like them.sorry couldnt resist

to be serious again,alu hasnt got half of the constant oscillation(fatigue as a point) strenght of steel and thats the big difference.a steel frame could be infinitely tensed with a fixed load if its designed for that load(dont beat me for that,it means,if weight didnt matter at all),an alu one is gonna break sooner or later ,no matter how its designed.

Edited September 13, 2012 by FamilyBiker

[clerictgm]

Is that actually based on anything?

It's just my opinion based on i've seen some snapped Inspireds (one even in 7 months) that belongs to average level riders and compare that cases to stresses that TRA puts on frame. If it's still THAT first hex he's riding - Inspired the best frames in the Universe.

And if he broke a frame - it's just disadvantageously to tell that to people.

Edited September 13, 2012 by clerictgm

[rocky111]

Your saying its half the weight, so you use twice the amount?

From your logic, both frames would weigh the same, and be as strong as each other

The fact that the alu if thicker makes it stiffer and stronger in a way, but it is more susceptible to fatigue, my brother is better at explaining it, he's an engineer for Porsche, he told me about it. you think he's wrong? what's your engineering background?

Edited September 13, 2012 by rocky111

[Mark W]

It's just my opinion

So the answer to my question is "No" then

As far as I'm aware, that's the same disc proto frame he's been riding the whole time.

[Martin Reynolds]

The fact that the alu if thicker makes it stiffer and stronger in a way, but it is more susceptible to fatigue, my brother is better at explaining it, he's an engineer for Porsche, he told me about it. you think he's wrong? what's your engineering background?

Gees, defensive much

I'm not saying your wrong, im saying i dont think it's as clear cut as alu is half the weight of steel and half the strength. When talking about a material's properties, there's so many factors: Compressive strength, elastical strength, resistance to fatigue, ect.

[Alex Dark]

I think the main property to look at with aluminium is how readily it fatigues ( this is what I have learnt from ND eng, no idea whether its true ). Aluminium will fatigue under any load given that it is put through the cycle enough times.

Had a little look on Wikipedia, and saw this

Having said that " The concept of endurance limit was introduced in 1870 by August Wöhler.^[9] However, recent research suggests that endurance limits do not actually exist, that if enough stress cycles are performed, even the smallest stress will eventually produce fatigue failure.^{[5][10] "}

So i think its a case that aluminium is far more susceptible to fatigue than its ferrous counterpart. Obviously things get a lot more complciated when you start looking at alloys and compositions as the attributes for each variation can vary enormously.

[rocky111]

Gees, defensive much

I'm not saying your wrong, im saying i dont think it's as clear cut as alu is half the weight of steel and half the strength. When talking about a material's properties, there's so many factors: Compressive strength, elastical strength, resistance to fatigue, ect.

didn't say alu is better an yes there are lots of factors I'm no expert just don't like being made out to be an idiot

[Al_Fel]

The only reason most trials frames are made from Aluminium alloy is because its cheap.

Case closed.

[Matthew62]

Genuine question.... with mountain bike technologies like bolt through axles how viable would this be to create out of steel? With the Skye being a relatively up to date bike in comparison to most trials bikes...could that set-up be achieved with steel? I mean there are no steel mountain bikes, and i'm guessing with all their linkages, forms, pivots etc steel wouldn't be viable?

I mean some MTB frames command a pretty decent price and if steel was stronger for a similar weight to alloy then surely they'd just make it out of steel? But it's always alloy or carbon.

I imagine it's more to do with the application of the frame as opposed to steel is just better for everything, but alloy is cheaper...

[Greetings]

And also - why not Titanium? For the cost of fourplay frame you can get custom Ti TRITON frame. So WTF? This stupid Al breaks down like cookies and world coolest manufacturers can't do a good Ti/steel frame? If it's now about weight and price of Ti, about what is it?

I think it's about how many middlemen there are in the process and the fact that anything with an Inspired logo is going to be 2x more expensive than something that doesn't have it no matter if it's OEM or not. You're right that a Triton costs the same as an Inspired but you buy it directly from the factory. With an Inspired it first has to be made by a factory in Taiwan, then shipped to Inspired in the UK and then shipped out to your dealer. So that's 2 more people that have to get their cut + 3 shipping companies. If you had a Triton dealer wherever you live I can bet you would NOT be able to buy it in the same price as from Russia. Taxes, shipping and profit included, you'd be lucky to pay only double what a Fourplay costs.

Personally I don't understand why Inspired frames are so expensive but at least they do a good job which justifies the price as opposed to some other brands whose frames just snap.

[Ali C]

shouldn't the question be, why are other frames so cheap?

[Matthew62]

£450... quite average for a trials frame and exceptionally average for a MTB hard tail. It's not like they shit either. And that's for a Fourplay frame - if you wanted cheap you could get an Element for £339

I bought my first Inspired frame in 2008 for £275 and I sold it last month with no dents, no cracks, no nothin' but scratches and a few different paint jobs. How many trials frames would still be going perfectly after 4 and a bit years?

They're a bit good so I can't say i've ever thought of them as even slightly expensive.

Edit: Didn't even realise the Hex was £399.... so not sure how you consider them expensive in a comparative sense?

Edited September 13, 2012 by Matthew62

[Greetings]

shouldn't the question be, why are other frames so cheap?

Let's not go there.

[Farmer Hickey]

Genuine question.... with mountain bike technologies like bolt through axles how viable would this be to create out of steel? With the Skye being a relatively up to date bike in comparison to most trials bikes...could that set-up be achieved with steel? I mean there are no steel mountain bikes, and i'm guessing with all their linkages, forms, pivots etc steel wouldn't be viable?

I mean some MTB frames command a pretty decent price and if steel was stronger for a similar weight to alloy then surely they'd just make it out of steel? But it's always alloy or carbon.

I imagine it's more to do with the application of the frame as opposed to steel is just better for everything, but alloy is cheaper...

Steel tends to be heavier, and depending on % carbon in it determines the grainstructure of the steel itself, thus determining the strength of the steel. High carbon steels are incredibly tough yet incredibly brittle as they have a austinetic/martensitic grain structure(depending on treatment), you dont tend to get that with aluminium as its a more malleable/ductile material.. Things like welded joints on the frame will have a degree of effect too, with both steel and aluminium as if its not treated the heat affected zone will have completely different composition to the main material itself so its swings and round abouts really.

[Mark W]

Genuine question.... with mountain bike technologies like bolt through axles how viable would this be to create out of steel? With the Skye being a relatively up to date bike in comparison to most trials bikes...could that set-up be achieved with steel? I mean there are no steel mountain bikes, and i'm guessing with all their linkages, forms, pivots etc steel wouldn't be viable?

I mean some MTB frames command a pretty decent price and if steel was stronger for a similar weight to alloy then surely they'd just make it out of steel? But it's always alloy or carbon.

I imagine it's more to do with the application of the frame as opposed to steel is just better for everything, but alloy is cheaper...

I'm not that up with my MTBing stuff, but don't DMR do some sort of steel full sus frame/bike? Seem to remember seeing something about that, anyway... I guess the 'problem' for doing through axles and stuff like that is that the dropouts tend to be fairly large lumps of material (the Skye frame dropouts are fairly large), so I'd imagine a CNC'd block of steel would end up being a fair bit weightier than an aluminium equivalent. S&M make steel 20mm through axle forks, but it's sort of different with those as the dropouts can be fairly thin plates rather than having to be a larger, threaded setup.

But yeah, I guess the forming possibilities of aluminium and carbon probably turn more manufacturers heads. Similarly, in MTBing I guess with everyone looking at alloy/carbon/ti setups steel might seem a bit 'dated' in a way, so might be a turn-off to some customers?

Personally I don't understand why Inspired frames are so expensive but at least they do a good job which justifies the price as opposed to some other brands whose frames just snap.

To use a fairly specific example, when Inspired changed from the '09/Element style dropouts to the newer dropouts with a custom hanger, that added a bit to the price but also added to the frame strength. They also tweaked the BB yokes and so on, so I guess it's just little changes like that throughout the bike that increase the price. If you directly compare the Inspired frames to 'rival' sort of frames it's pretty clear where that extra money's gone to. They are expensive frames though, but I guess you're sort of 'rewarded' for spending that little extra by getting a stronger, stiffer frame.

[bike_dummie]

I thought it was the minor flex you get with steel affected the rear suspension pivot especially when you get the frames with the complicated pivots its ect. Although mtb isnt really my thing So I may be wrong.