Hi all, I’ve had many bikes over the years and all of them have either been Alu or steel. I have never broken any of them to this day. Now I’m seriously looking at the new SC Bronson CC, but I don’t have confidence in carbon for some reason. I’ve never had it, but keep reading horror stories about them breaking.

The Alloy version isn’t out until April and not sure if I want to wait that long. It will be used for local trail, uplift days at FOD and a week a year in the Alps. I’m not into massive gaps or full DH but it’ll be used on DH trails ranging from sand to rock.

SC offer a lifetime warranty which is why I’m even considering it. I currently ride a Alu Nomad and know that if I fell off it, it would dent but be structurally ok. My worry is, that if I took a bad fall on a carbon bike, would I worry that it’s going to snap on the next landing?

Please help as I can’t decide!!

Google the Santa Cruz carbon test video.

Technically they are stronger but it is your call as the damage on metal is much more accessible

FWIW I have snapped both but prefer metal for the reasons you note

Have you seen how thin aluminium and quality steel tube walls are 😯

I’m sure I read somewhere the tubes on my ti frame are 0.3mm thick. Best not to think about these things, just get on and ride them. If they were breaking all over the place, the companies wouldn’t be in business for long.

Edit – lifetime warranties refer to the anticipated lifetime of the bike, read the small print as this is sometimes as little as a few years.

I’ve seen the video, and it’s very impressive, but it still feels like plastic to me.

I was a plumber/heating engineer for 17 years up to last year and I never used any plastic pipe. The copper just feel more robust. Same theory with bikes I suppose.

40MPG – I think I read it’s 5 years, but I only keep things for 2 maybe 3 including our cars so that’s ok. I get bored easily!! I’m suprized my wife has lasted 10!!

then wait for the metal one. It’s always going to be on your mind otherwise.

I’ve ridden carbon bars for the last 10 years, frames for the last 2 (Santa cruz’eses, as it happens) and, touch wood, never had a failure, despite crashes, racing a couple of enduros and 6 weeks (over 3 trips, years apart) in whistler. I’m no more scared of breaking a carbon frame as I am a metal one, but then I’m hardly ratboy. I’m sure there have been just as many metal frame failures as on carbon frames, it’s just people seem to froth a bit more when it’s expensive carbon (a £3k frame shouldn’t break evaaah!!!11!one) and more so when it’s a Santa Cruz, so you hear lots about them.

Which year nomad do you have? I can’t imagine being happy with a Bronson coming from a nomad. Even the old ones are amazing.

I was a plumber/heating engineer for 17 years up to last year and I never used any plastic pipe. The copper just feel more robust. Same theory with bikes I suppose.

I’m not sure many frame builders would agree with your comparison. Not sure how the robustness of a water pipe has any similarities with an MTB frame.

I’ve got the carbon Capra and I had similar concerns about it (the alloy version didn’t exist when I bought it) but they have been proven unfounded really.

The frame has taken some serious rock strikes over the last year and it’s shrugged them off without a problem.

Having said all that, if the Al version had been available I would have got that, not convinced it really makes THAT much difference to the ride.

Read about metal fatigue and aluminium, then consider that carbon doesn’t suffer from it.

By ‘feel’ are you referring to what it feels like to the touch? What you are feeling there is paint, not CF or metal….

My Nomad is the Last of the 26″ brought late 2013. I love it to bits, but I want to get back into doing loner rides and the Nomad isn’t the best climber in the world. I wasn’t going to change it until I saw the new Bronson. It’s sooo much lighter! I know it’s not going to be as good going down hill, but it’ll do everything else better. The Nomad for me only comes into its own in the Alps and I couldn’t think of a better bike out there. I just can’t justify keeping it in the shed for one weeks riding a year. I’m also stunned by how little it’s now worth!

Tomhoward – that’s good to hear! I think it’s just the sound it makes when you tap it. Sound like you could snap it in two with your hands. I know you can’t but you know what I mean!
Poison spider – it’s just new materials like carbon/plastic pipe. I came into the industry before plastic pipe was used and never felt happy swapping what I used. I wasn’t directly comparing plastic and carbon. It’s just a fear of the Unknown I guess.

I know you can’t but you know what I mean!

Nope. I trust engineering, as do you when you get on an alu bike!

If you dent or crack thin aluminium then it’s generally game over for the frame. Carbon can easily be repaired. Carbon also doesn’t suffer from fatigue in the same way as metal and doesn’t oxidise.

If toughness and longevity is your main concern, you should go carbon.

I’ve just watched that SC video again, and that really is impressive. My concerns were the amount that fail, but people only post on the net when they have a problem and never when things are going well. Like it was said above, a 3k frame should never break, but when it does, people shout from the roof tops. I’m sure out of all the carbon frames sold only 1% ever break.

Lots of alu frames fail too, you know!

Molgrips – I know and I’m sure it’s just as many. The fact that SC have the confidence to offer lifetime warranty helps.

A guy I know rides carbon:

https://instagram.com/p/4xPDUqmZbm/

Seems OK.

Doesn’t stop me having the same doubts as OP but it’s stronger, lighter and easier to repair if you have the cash.

I really wouldnt be too worried about composite bikes failing. There are a few areas that if they fail will mean a new frame/rear end as they are difficult to fix (bonded pivots etc) but those will generally be covered by warranty. Impact damage in most places can be fixed. Only something catastrophic like ripping the head tube or BB area off is likely to be terminal but if you have done that then you would have probably trashed a metal frame too and I suspect you will be more worried about your own injuries.

I work in composites but I do have to admit I am having real problems with the sustainability aspect for general consumer use as it’s just not recyclable like a metal frame. Slightly hypocritical of me to have just ordered some more LB rims for my new aluminium full susser (I could have gone the carbon option) but I don’t tend to trash stuff and a decent set of wheels will last me years (I have been running my set of 26″ Mavic 717s since 2008 now and am just about to fit them to the OHs bike instead of selling them as they are worth bobbins) so they will probably last me 2 or 3 frames which I will change due to wanting to as I can’t see me needing anything wider than 30mm ID for a while and the benefit of composite wheels outweighs that of the frames IMO.

But I am sure the composite bike will be lighter and stiffer and probably stronger and tougher.

My concerns are especially valid for cars were I see the use of non-recyclable materials in general use cars as a step back from metals.

I also managed to bend a steel one with very little effort. It was replaced though (ta Salsa).

but I don’t have confidence in carbon for some reason

Then don’t buy it, there’s no point trying to persuade yourself, or get others to convince you when the fears (however unfounded) are so ingrained… Just go with what you understand…

Yes, aluminium alloy fatigues – maybe in about 500 years of use your alloy frame might crack due to fatigue. You’re talking hundreds of thousand or millions of cycles before fatigue is an issue. Cracked alloy frames are most likely caused by plain and simple over-stressing from abuse. Aluminium Airplanes with fuselage skins a few mm’s thick fly around for decades before they use up their fatigue life – and it’s usually corrosion that kills them first. It’s taken many decades for carbon to find its way into large aircraft and it’s no lighter (yet), and turns a fuselage skin repair from a few hours work most line mechanics can do, to a few weeks work that can only be done by a specialist team sent by the OEM along with a load of specialist kit – but it’s early days.

But mountain biking is a kit sport and we like a bit of snazzy kit. I’d say, if you fancy a carbon Bronson then get one. Not because it’s carbon, but because it is a brilliant bike – why not, life is too short. Just make sure you’ve got a good warranty and crash replacement cover. Again, not because its carbon, but because its a £5k+ bike!

My friend spent 6300 on a mojo hd3 used it for 4 months and now the swing arm has cracked and he is back on his ali mega waiting for warranty. He is not too fussed as he has the mega but for me I would be bike less and annoyed.

I have broken one steel frame and two aluminium ones. Have been riding a carbon full susser for the last three and a half years and it has been fine.

In the very short ride I had on one ( a full demo is booked!) it rode beautifully. The extra 25mm on the top tude really helps as I have stupid long arms and just over 6ft. I want it not because it’s carbon, but as it rides so nicely and ticks all my boxes.

I have brought 3 frames through the dealer and he is offering me 10% off. I’ll chat to him re. Warranty/crash replacement etc.

I’m sat here tho looking at the Nomad and damn that’s a nice bike

He is not too fussed as he has the mega but for me I would be bike less and annoyed.

Didn’t most of the original Alu Megas have stupidly weak chainstays that snapped or were replaced before snapping?
Specialized had a habit of making chain stays that snapped 02-06
Commencal a few years back couldn’t make large Meta’s that didn’t fail
Plenty of bikes fail, the material has little bearing on it.

Been riding carbon bikes for over 2 years now, I’ve abused the Blur LTc for all that time and it’s been solid, a 5 year warranty is enough for me on a bike and the confidence is great.

Carbon brings out irrational fear, I’ve seen many more failed Alu and bent steel frames than I ever have in Carbon.

Newer generation mega, you are more likely to see bent steel and failed ali as there are loads more about.

The main thing that bothers me about carbon vs alloy is the working conditions in the factories where the frames are built.

Yes a carbon frame can be stiffer and stronger and lighter, though usually less robust in impact or crash situations but for an amateur is the marginal gain worth the much lower wages, poor health and safety or environmental controls and crap lives of the people in China laying up carbon – especially compared to the modern clean safe factories, decent pay and much better lives of the highly skilled welders in Taiwan?

A guy I know rides carbon:

https://instagram.com/p/4xPDUqmZbm/

Seems OK.

Boom! Nice pic.

gravity-slave – Member

A guy I know rides carbon:

https://instagram.com/p/4xPDUqmZbm/

Seems OK.

Um….didn’t I see a video of this going horribly wrong and the bike getting destroyed?

Yes, aluminium alloy fatigues – maybe in about 500 years of use your alloy frame might crack due to fatigue. You’re talking hundreds of thousand or millions of cycles before fatigue is an issue. Cracked alloy frames are most likely caused by plain and simple over-stressing from abuse. Aluminium Airplanes with fuselage skins a few mm’s thick fly around for decades before they use up their fatigue life – and it’s usually corrosion that kills them first. It’s taken many decades for carbon to find its way into large aircraft and it’s no lighter (yet), and turns a fuselage skin repair from a few hours work most line mechanics can do, to a few weeks work that can only be done by a specialist team sent by the OEM along with a load of specialist kit – but it’s early days.

But despite using similar materials, commercial aircraft and mountain bikes are constructed in vastly different ways – Bolted joints aren’t really ideal for carbon, and are used everywhere on aircraft and if aircraft were to go full carbon then a large weight saving would be realised (I’m not totally sure I agree with your assertion that carbon fibre hasn’t saved weight on aircraft even currently) as a lot of extra material is needed to cope with thermal stresses between metallic and composite sections of the aircraft.

Also, I can assure you I have broken numerous components (on the commuter mostly) and a couple of frames (all metallic though I’ve mostly had metallic frames) through fatigue. The fatigue life is totally dependent on the cyclic loading, and some mountain bike components may not be built to take the millions of cycles you put them through by pedalling. And, despite all this, some aircraft components do fail though fatigue. Client confidentiality prevents me from listing a number of issues (and yes of course composite failures occur too, for different reasons).

That said, carbon bikes will have metal parts in them and these may fail through fatigue, and I’m sure other degradation mechanisms will kill carbon over time. The fact remains however that a big enough impact will severely damage any frame whether carbon or aluminium.

Didnt using composites shed 12 tonnes from the overall weight of the a380 or did the discovery channel lie to me?

The fact remains however that a big enough impact will severely damage any frame whether carbon or aluminium.

And the carbon can be easily repaired.

The fact remains however that a big enough impact will severely damage any frame whether carbon or aluminium.

And the carbon can be easily repaired

Probably in time for you being discharged from hospital if you have good riding buddies/a good SO.

Seen 2 top tube damages due to not enough spacers and brake levers. Both repairs look like new. Much happier on either of those frames than an aluminium with a massive dent (which happens much more easily)