So… still pondering on a new frame. My last full sus frame famously lasted me for 14 years (and is still going strong), which is pretty much a record for me anyway as prior to that I want through frames quite quickly. Guess frame strength peaked around 2000 when freeride and massive hucks to flat were in their prime.
The full sus frame I’m looking at replacing it with is available in either Alu or Carbon – any guidance on which material is most likely to make it another 14 years? My suspicion says that carbon has a longer (infinite) fatigue life than alu but is also more likely to go *bang*, so maybe Alu is better (my current frame is overbuilt Alu)?

My carbon frame has a 5 year warranty and lots of alu ones only have a year…
Not evidence but happy with carbon, it can also be repaired much easier.

Carbon will have a much longer service life due to not suffering fatigue but is more likely to suffer crash damage.

Composites are almost impossible to recycle, unlike metal. Even if a carbon frame lasted longer, at the end of it’s life it’ll become land-fill.

This may or may not bother you.

(3kg of landfill at the end of 5/10/15 years doesn’t seem that wasteful to me, but i know it bothers some people)

chiefgrooveguru – Member

Carbon will have a much longer service life due to not suffering fatigue but is more likely to suffer crash damage.

Shite. Unless you have evidence?

Who rides frams till they break and then recycles them?

Who rides frams till they break and then recycles them?

Read the OP al.

14 years!

Who rides frams till they break and then recycles them?

Err Me? Who rides frames then swaps then out on a whim?

Stevet1 – Member

Who rides frams till they break and then recycles them?

Err Me? Who rides frames then swaps then out on a whim?

You’re new here right?

if you nail your bike down runs then get an aluminum frame, save the money for something else. Carbons fine but doesn’t crash well and the minor weight saving vs alu is it worth the extra grand or so? if you use it for xc with the odd bit of downhill sup to you. I crashed my alu frame into a gate post 6 months after getting it, had a dent in the downpipe ever since, carbon doesn’t dent!

Composites are almost impossible to recycle, unlike metal. Even if a carbon frame lasted longer, at the end of it’s life it’ll become land-fill.

This may or may not bother you.

(3kg of landfill at the end of 5/10/15 years doesn’t seem that wasteful to me, but i know it bothers some people)

The Carbon footprint/waste arguments are quite interesting actually, Steel/Aluminium/Titanium are hardly carbon neutral, turning ore into a frame takes quite a bit of energy and wasted material, very few Aluminium frames will be made from recycled material (which also carries a substantial carbon footprint).

While Carbon and Epoxy resin are also far from environmentally friendly, Composite frames are relatively easy to repair, so their useful life should go well beyond their warranty period/first owner, While people blather on about the repairability of steel and Aluminium frames, quite a few do still get ditched rather than re-welded after that first crack or dent takes that new bike shine away… It’s a null and void point IMO, neither will save mother earth…

In terms of simple mechanical strength Vs weight Carbon composites “Win” in terms of fatigue life? Well it’s anyone’s guess TBH, it’s not the actual carbon fibres I’d worry about so much as how the epoxy matrix it’s held in lasts over repeated loading cycles, and with any potential exposure to UV?
There are Early trek OCLV frames still in service after ~20 years, but it’s still a relatively new technology which has undergone quite a bit of refinement/change since the mid 90’s with limited available long term test samples… Up to now Composites have been seen as relatively “Disposable” so how well they suit longer term use is not fully understood yet IMO…

Arc welding is a ~200 year old technique for joining metals, variations on it (GTAW / TIG) are often applied to aluminium so their is (arguably) about ten times the historical knowledge, and empirical data behind that method of bike frame manufacture, but it’s still a fine skill and people still manage to produce duff welds on occasion… Draw whatever conclusions you can from that.

So in answer to the OP’s question…
I don’t believe anyone really has an honest idea which will last better, I’m inclined to say a well designed composite structure should last as long as a well designed, welded aluminium structure but neither comes with an infinite guarantee…

Who rides frams till they break and then recycles them?

Er.. me.

Either repaired/welded if possible, or gets recycled/upcycled into something useful (workshop stool, pen pots, etc.) or if properly terminal and all useful bits used then goes to local artisist/ scrappy/recycling centre.

Very occasionally I’ll sell a frame if still in good condition, but mostly I keep stuff till it breaks.

Back on topic though, OP, I’d say its swings and roundabouts at this point, carbon would be my choice if you can afford the difference, it’s easily repairable, not as fragile as people make out and should last a good long while as long as not abused. Frames break when they either suffer damage beyond design limits or through fatigue or as a result of defect, the above is true regardless of material, and honestly I think defect or damage are more likely over the lifespan than a fatigue failure.

Give us a hint though, what is your current frame, and what are you looking at as replacement?

There’s probably a bit of affiliated bias too- if you’re making a carbon frame you’re more likely to want to make lightness a selling point so may push the margins harder. If you’re making a 7lb alu frame you’re probably less inclined to shave grams.

My old Foes frame which cost $1500 in the late 90’s got chucked in the recycling skip after it cracked / got repaired 3 times.

I’ve got an 8yr old carbon Enduro that’s got less damage to the frame than the 6yr old alu one it replaced – that’s all the input I can give really

Thanks everyone for their input, interesting opinions although as expected I guess no real conclusions to draw.

There’s probably a bit of affiliated bias too- if you’re making a carbon frame you’re more likely to want to make lightness a selling point so may push the margins harder. If you’re making a 7lb alu frame you’re probably less inclined to shave grams.

I do wonder this. But I also wonder that people are looking closer at the carbon parts and expecting them to fail so they may actually be overbuilt.

Give us a hint though, what is your current frame, and what are you looking at as replacement?

I didn’t want to initially as I wanted an unbiased view of the materials but seeing as you’ve asked –
Current frame is a 2001 Turner RFX (9lbs of aluminium radness)
New frame probably set on a Yeti SB66 in alu or Carbon. Probably veering towards the carbon. No longer available new so looking for very good conditions second hand. I should have bid on this in hindsight…
http://www.ebay.co.uk/itm/Yeti-SB66c-2014-medium-/252012185266?pt=LH_DefaultDomain_3&hash=item3aad18c6b2