[Closed] Alloy vs Carbon FS MTB frames, real world differences.

I guess the carbon will be stiffer (unsure how much?) and the alloy will be more recycle friendly

It will be stffer if they have designed it to be stiffer. How many bike frames have you recycled?

It’s lighter, easier to repair than alu and blinger, everything else is subjective.

Carbon, build the stiffness and flex exactly where you want it, make shapes you can't with Alu etc.

I've ridden the same older SC frames in Alloy and Carbon, there was a bit of extra stiffness in the Carbon but not much, I'm more noticeable in my road bikes.

IMHO the lines always look better without welds though 🙂 and that is what matters

Because being able to build in the stiffness where you wanted it using carbon worked so, so well in Moto GP with their R&D budgets that dwarf the mtb world.

Stick to aluminium, use the spare money to save rotating mass, unsprung mass and then mass at the extremities of the bike - eg the seat. Centralise the mass.

Because being able to build in the stiffness where you wanted it using carbon worked so, so well in Moto GP with their R&D budgets that dwarf the mtb world.

yeah cause motorbikes......

Only 450 difference between alloy and cc ( once you factor in postage) from ITM racing on eBay- if your med or large

£800 to save 2.5lbs is better than the old bench Mark of 1£/g

Interesting @ITM, but those are v2’s not the current model which probably explains price.

I’ve got a nice new set of fairly light wheels (c1800g @30mm internal) in the cupboard already that I’d be expecting to use if this happened. I’m not generally a weight weenie and have honestly never actually weighed a bike, just worked on a ‘head’ number of around 30lb being a number I don’t really want to see higher than if build weights are advertised. I’ve put together a vague spreadsheet that seems to show an alloy/pike/GX Eagle 5010 coming in around 28.5lb and a CC with X01 around 25lb. I’m quite sure actual weights will be more, I’ve not accounted for sealant and cables just off the top of my head and I’m sure there will be more. Especially as these are below SC’s own full build weights and I’ve not even really looked at lightening things, just picked the things I like. The CC and X01 build goes north of £6k and scares me although isn’t necessarily unaffordable - but obviously no one wants to spend money they didn’t need to.

Really, I was canvassing for reasons to pick carbon over alloy, I’m not sure the stiffness will matter to me, so really it was ‘is there more to this than weight?’ The Alloy 5010 does look different than the carbon, but not as alien-freak different as metal vs carbon used to, they’re really very similar.

Onza, £1/g figure noted. I’d probably want the nicer shock although I’d probably be happy with the performance elite over the full factory/kashima but yep, once it’s rationalised down to ‘only £800 more and 2.5lb lighter’ it is looking like not such a silly deal maybe. Tbh, this was really where the question began in my head...

Plus, if you go alu, you'll always have the 'I wonder if the carbon was/is better' nag in your head...

Not the bike your looking at but there was an interesting article on NSMB.com where they took identically built Knollys but one carbon and one aluminium.

Might be worth a read.

I’d rather spend my money on something other than a marginally lighter frame that’s more unpleasant to manufacture and harder to recycle when it dies. To me the fork, shock, brakes and even dropper are more important.

Now that people are accepting that more stiffness isn’t always better, maybe we’ll see the recent obsession with carbon die back a bit?

Also, although carbon is easier to fix, it does tend to be more susceptible to crash damage.

it does tend to be more susceptible to crash damage.

Yeah, mine are full of dents.

Aluminium is extremely toxic, polluting and energy intensive in manufacture more so than carbon. In fact there is no Al ore processing allowed in the EU as it’s impossible to meet environmental standards. It’s all done in Nigeria I think, except for a small ore processing plant at Tooreenard co Limerick in Ireland which is to be phased out. Go on google earth and look at the horrendous pollution there, and that is only one part of the ore Process. The giant red ponds are full of cadmium and arsenic left over from purification.

So the ecological arguments aren’t at all clear cut. Carbon is very difficult to recycle agreed, but the fore life is better.

I wouldn’t choose aluminium over carbon for ecological reasons.

gkeeffe - you know there's a large aluminium smelting plant in Fort William, right?

@billoddie, that NSMB Duelling Knollys article was very interesting, thank you! All the more so because it turned out that no-one agreed anything except that the alu bike was cheaper, but as pointed out in the comments and article, Knolly may be a special case in terms of not having deprecated their alloy product as a result of carbon.

gkeefe, point taken but it does become a little more complex as reuse potential for carbon is much lower than it is for any metal. Crossing with Tom from the start, personally I've only sent a few broken frames for recycling, usually I'd be selling on if I wasn't keeping although I'm not a serial swapper. Point very much taken that neither are particularly clean in first production but after that it's considerably less clear cut I think, particularly if you expect to hold on to the bike a while. The more I think about it, the more carbon seems like the new Ti...

Definitely one to think about.

https://nsmb.com/articles/duelling-knolly-wardens-final-verdicts/

So aluminium for Breathing With the Trails?

Placebo effect I’m sure, but for me if I bought the alloy (cheaper) frame I would have a constant nagging doubt. Plus the residual values seem better, so arguably the better retention will reap some rewards in the future.

I emailed transition about this and got a reply from 2 people, they said they are engineered to ride the same. Share similar properties basically. Same stiffness etc. It was sort of put if you have the spare cash, get carbon if not get alloy!

Is this a long term purchase.. how long do you keep your bikes for.... ? If its a long termer, maybe get good kit and nice touch points that make it feel special.... If you look at a frame as a place to attach other stuff, carbon frames are nice but mediocre kit might take the edge off it.

Long term purchase, get the one you really want....
If you chop and change regularly, good finishing kit and swap that across...

gkeeffe – you know there’s a large aluminium smelting plant in Fort William, right?

I think its the steps before that he is talking about

There's a lot of overlap I think, in terms of weight and the way they ride.

Carbon can be lighter or about the same as alu. It's usually stiffer but sometimes too stiff.

It possibly makes most sense for shorter-travel bikes which will be doing less hilly (and potentially less rocky) riding.

Less rocks = less chance of ****ting the frame on one but also rocky trails are where the extra stiffness of carbon may be felt negatively.

The ecological angle? Largely poisturing by partially informed bike companies with an agenda or keyboard warriors. The evidence is inconclusive. I think all the hot air spouted about it is more environmentally damaging than the production of a relatively small number of high-end bike frames.

https://nsmb.com/articles/duelling-knolly-wardens-final-verdicts/ < So aluminium for Breathing With the Trails?

The change in contact patch feel that was described by the second rider is roughly in line with what motorbike racers have experienced as well - however, the loss of information being transferred to the rider has not been viewed as a good thing in that sport.

I bought a 2010 Stumpjumper FSR in alloy, which had a paint issue & was warrantied about 6 months later by Specialized. They had no more alloy mediums available, so said I could either wait until the 2011 bike was released, or pay £50 and upgrade to the carbon version;. which I did.

Apart from it having the Brain shock whereas the alloy one had the standard Fox Triad fitted at the time, I can feel no difference in the frames at all.
I probably wince a bit more when I get a large rock-strike, but I suspect my mince core skill level isn't up to discerning any real-life difference between the two.
The carbon one does look bloody nice though.

What advantages actually are there when all is said and done apart from a chunk of mass?

I expect if you blind tested the same bike with the same kit on it, with the frame difference being the only variable, 99% of people couldn't tell the difference.

I expect in reality, with just 1kg of weight difference, all other things being equal again, you couldn't tell that either on a bike that weighs 13/14kg.

There will be no appreciable difference other than weight. As said, £800 is a good incremental price. And have an alloy Defy and a carbon SL Defy. Whilst one has lots of bling and is bang on 7 kilos, the alloy is a kilo heavier but rides the same (for 10% of the price!)

If you want carbon, buy carbon. But £800 buys a lot of riding somewhere nice. Or a SS to ride in the slop instead.

Not sure about the environmental arguments for carbon over aluminium. The reason they don't have primary alumina plants in the EU is that the ore (bauxite) is part of a tropical weathering profile and therefore is mined in the tropics (e.g. Brazil, Guinea, Jamaica). Transport costs would be huge to ship that to Europe before doing some primary processing. The actual process of Al smelting is ridiculously energy hungry however.

Even if you bought a carbon bike, a lot of the componentry would contain metals of varying types (Al, Fe, V, Cr, Ni etc..). Unfortunately, there is no getting around the fact that metals come from a hole in the ground (even if recycled) and there will be environmental consequences associated with any of these.

Carbon frames are reinforced plastic, but the actual carbon production involves a mine of some kind and ore processing. I'm not familiar with this, but you can bet the process of production is not gonna make the world a better place.

“Yeah, mine are full of dents.”

I’m never quite sure how useful your views are based on what you’ve implied about how many bikes you own, how much you ride them and how hard you ride them.

the ore (bauxite) is part of a tropical weathering profile and therefore is mined in the tropics (e.g. Brazil, Guinea, Jamaica).

Australia and China account for about 50% of world production.

If you're building a new bike to a set budget, buy the Alloy frame, use the saving to buy suspension with better damping, higher spec drivetrain components and lighter wheels. You'll get a much better perfoming bike than by saving a few grams on the frame, and the better parts will weigh less where it matters most.

easy. carbon is for road bikes. aluminium or steel for everything else.

I’m never quite sure how useful your views are based on what you’ve implied about how many bikes you own, how much you ride them and how hard you ride them.

Shots fired!!

Buy whatever one you like the look of, I'm pretty sure the VAST majority of folk on here couldn't tell the difference when actually riding* - me included. I bought my Bronson CC cos I liked the look of it, and my lbs did me a cracking deal on it, otherwise alloy would've done me.

*apart from mibbe road bikes, cos it's so dull you may actually notice the different ride.

So pretty much the settled view of the forum is that it’s lighter, more expensive and possibly prettier. Pretty much where I already was, with head says Alu and heart says ‘ooh, carbon’ 😂

The decision made isn’t going to make much difference to the initial build, I already have the wheels I plan to use and that’s where the big useful weight saving always is. The Knolly article and discussion has been genuinely useful though, always good to know you aren’t necessarily missing something if you’re struggling to see the point...

I have the 2019 alloy 5010 frame and it's plenty stiff believe me, I really like the look of the welds and the massive box of metal around the BB too, but taste is subjective!

If I had cash to spare I would've dropped an extra grand on the CC frame, but I didn't and to be honest after a few weeks on my new 5010 I don't regret not going carbon.

As others have said the geometry/stiffness is the same (that's what SC say) so save your cash and spend the money on those bits.

Whatever you get the 5010 is an incredible bike - bump the fork up to 150mm and it's unstoppable.

150 front is entirely what I'd planned. I'm a big fan of 130r 150f bikes... 🙂

Good to get the specific feedback too!

I think it's time that as men we should point out to other men it's ok to not ride carbon....the best a man can be

Re earlier comment - yeah I was talking ore processing.... not smelting.

Forgetting the much higher ecological damage of ore mining, Aluminium production overall uses 170 kg CO2 per kilo versus 60 kg for carbon, and carbon bikes are a 1/3 lighter - so less material makes Carbon 4x less energy intensive per bike.. Recycled aluminium is not used for bikes (too weak). Water usage is about the same per bike. Carbon also lasts a lot longer re fatigue so the bike should remain in service longer, and it's easy to mend - Aluminium can't generally be re-welded.

No material is perfect, but I think carbon is better for the environment overall. It can be recycled and is being more widely - but what it produces is generally cheap plastic replacement parts... Note I have carbon, steel and aluminium bikes in the house, so I'm no zealot.

What about the failure and rejection rates in the manufacturing process? I’m sure I recall seeing piles of carbon frames that were rejected and are fit for little more than conversion to thermal energy. At least rejected aluminium frames can be recycled.

https://singletrackworld.com/forum/topic/piles-of-rejected-carbon-frames/

What about the failure and rejection rates in the manufacturing process?

Those pics are the Ali baba warehouses

If you're buying frame only and building, I'd be thinking pretty hard about buying the aluminium version, same angles, tiny bit of extra weight, probably wouldn't notice any real world ride quality difference. If its a factory built bike, the carbon versions tend to be better specced.

The bike industry is so tiny in comparison to others the environmental or recycling value of the different types of frames are meaningless in the wider sense

I never cease to be disappointed when I test ride a carbon bike. the weight difference is not noticeable and they perform as well, but not better than decent metal equivalents. The price premium is just not justifiable for me, i'd rather buy metal and bolt on better components. There are still a number of Carbon bikes I have on my test ride list and I still hope I have that moment where I'm so impressed I'm immediately digging out my credit card because they are damn nice bikes....but I'm not holding my breath. If you test ride a carbon bike and prefer it over a metal counterpart it wont be because the bike is made from carbon...there are so many other things and aspects of bike design that come together to deliver the final product and its performance, and frame material is only one minor part that goes into the mix, so on its own wont define a good bike.

Don't get so hung up on these things. Look at the bike in the round and how it performs for you. The market is pushing carbon because they can justify an astronomical price premium. For the pro's no doubt the small marginal gain performance benefits of carbon matter...but for us mere mortals its just not relevant. But i'd never blame anyone for buying something purely for the bling factor...i'm guilty of this and there are some damn fine looking carbon bikes out there...but lets be honest with ourselves and stop kidding ourselves we NEED one. People accept that someone might buy a Porsche for many reasons other than they are a driving god and need one to get the best out of their driving skills. People buy them because they like them, because of the image they want to portray to others, because its a life's dream and symbolises they've achieved their goals in life and made a success of themselves, they buy them to impress other people etc. Why should mountain bikes be any different?

Only to add some noise, regarding aluminium:

the aluminium frame industry advanced as well. Old aluminium frames were thick wall, simple things.

Now with hydroforming, high strength aluminium the frames are "pieces of art" in my opinion.

Aluminium bikes and carbon bikes are so capable these days. If a bike holds up depends more onto the quality control of the company - and not if it's carbon or aluminium.

Maketing issue: yes - there is a tendency in direction of "more carbon" frame designs.

Horses for courses Wobbliscott. I've never ridden a steel or aluminium road bike and thought it was better than my lightweight aero carbon bike.
My old winter bike was the aluminium version of one of my carbon bikes. The weight was similar but the ride is just way nicer on the carbon bike (Trek Domane SL with the front and rear Isospeed).
My carbon good bike rides like a dream (Canyon Aeroad). Weighs just over 7.2kgs and that's with 65mm deep rims. With road bikes though it depends what you want out of them. I want a fast, stiff but light bike with an aero profile. The only metal aero bike I'm aware of is the Specialized Allez Sprint, which is a good bike, but not the lightest. My Trek Emonda SLR (now gone) was 6.5kgs, I've not seen any metal bikes at that weight. (I've owned and ridden lots of metal road bikes over the years, they don't compare in my opinion to a top level carbon bike for my type of riding and racing). Other people may want steel for its compliance, if I was audaxing I'd probably do the same. For when I used to just race crits I used a light aluminium frame, but it was no better or more robust than a carbon frame, it was just cheap and affordable to replace.

On the mountain bike front I had a 2017 Trek Fuel Ex carbon bike as a demo for a week. I then took out the aluminium version which was cheaper but had better wheels and suspension. To ride the frames felt identical, no noticeable weight difference. I purchased the aluminium Fuel Ex as it was £300 cheaper and came with better kit.

I had the choice of Al or Carbon when buying my remedy frame. I decided that the £1k was better in my pocket and ment I got the fox 36 grip2 over a lesser fork and still have money left over for a shock upgrade in summer if I want it. I think that the quality of suspension is far more important than frame material.