Probably these were alloy 
- Assuming the typical use of this term, meaning aluminumā¦ nope.
Those are Bontrager Aeolus XXX 2 wheels, with steel bladed & butted spokes, and āalloyā aluminum nipples. The cold forming used to shape them makes them quite strong. Possibly even stronger than a regular round spoke of the same weight.
All that said, I am also surprised the failure point was the stays and not spokes (canāt see broken ones, but the pic is incomplete).
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it was meant as a joke.
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In general, ride quality is differentiated by tube stiffness, tube strength and geometry. Further, how this interacts with rider body weight is important. There are unresolved questions currently being solved out there about things like shimmy and why a bike rides in a straight line when you donāt have your hands on the bars.
https://www.popularmechanics.com/adventure/sports/a6602/physics-of-a-riderless-bike/
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Every material will have its pros and cons.
For me, I ride a CAAD12 with Di2 and carbon searpost/bars and itās bliss. Nice black inc wheels.
If making the step to spend a few more Ā£$ā¬ then I would personally look at CAAD13 and a top mechanical groupset. Especially if you like a crash/have a few bumps. Carbon, then a giant TCR
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Get a trek Emonda if you want light weight alu. I wouldnāt be afraid to ride carbon, it is tried and true. However, I abuse my gear pretty hard so I opted for an Emonda with the mindset that I want to be able to buy another / repair what I own rather than shelling out the bucks with my fingers crossed that nothing goes wrong
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Why are people who abuse their stuff opting for aluminum, considering it cannot be repaired? Iād bet that if you decently damaged both a carbon and aluminum frame today, youād have the carbon one back from repair (which would probably not be possible for the aluminum) sooner than you could buy a new Aluminum frame and junk the old one.
Carbon frame = higher up front cost, lower cost of repair.
Aluminum frame = lower up front cost, impossible to repair
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Iām 94kg and have crashed my SuperSix Evo HiMod 5 or 6 times, many of which were 20-30mph. It is Cannondaleās lightest and presumably, weakest, carbon frame.
No carbon damage. Plenty of paint and component damage.
Iāve ridden it on pot-holey gravel roads with 28mm tires. Iāve jumped up and down curbs. All totally fine. If the crashes didnāt kill it, no non-crash riding is going to harm it, given the suspension the tires provide.
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I wouldnāt fret.
Carbon parts, including bike frames, are robust and donāt need to be babied the way you describe. Iāve been through huge potholes and the like without any issues. People I know have crashed their carbon bikes to no ill effect. Modern carbon bikes are solid, especially during normal use.
There are a few things to keep in mind: when you get a carbon frame, you have to get a torque wrench. If you have a good bike (even with a metal frame) you will need one anyway, because many parts (including cranks) need to be torqued up correctly. However, since carbon is weakest against clamping loads, this is more important for carbon frames and parts. So just pay attention to your torque specs for seat tube and cockpit (if the latter is carbon). You also should avoid impacts on sharp objects like corners of walls and the like. Again, you donāt need to freak out if it happens, just try to avoid it when you can. Also, you should think twice if you see really light parts, e. g. that carbon wheelset that weighs only 1,100 g ā it might be more of a nuisance than carrying around 400 extra grams with you.
As far as I can tell the reputation of carbon being fragile is due to three main factors: (1) Carbon frames tend to be made to be as light as possible since it is, well, the lightest material for frames out there. That means you sacrifice structural rigidity for light weight. But thatād also happen with light frames and parts made out of other materials. You can get downhill mountain bike rims out of carbon that are almost indestructible. Think of a sports car: why are they much more prone to breaking? Well, because they are pushing all of the components much closer to the limit.
(2) The failure mode of carbon is different from metals: it tends to be either completely ok or completely broken with little in between. My aluminum frame of my mountain bike has two dents in it. In a carbon frame I wouldnāt have these dents, carbon would either have sprung back with no visible damage or cracked. As a consequence, carbon is often much more resistant to fatigue than metal. Carbon parts become practically unusable once damaged whereas metal parts may be used longer. However, in many cases (again, downhill mountain bike frames are an example I can think of) carbon parts can be actually much tougher than their metal counterparts, so they can take more of a beating until they are damaged. (I write practically unusable, because carbon repair is a thing, but Iām not sure if I wanted to trust those parts again.)
And (3) because carbon parts tend to be either completely ok or broken, people are afraid of catastrophic failures even though these are exceedingly rare. It does happen, but rarely and even if it does, often the rider is completely safe. Remember the failure of the handle bars of the Australian track rider at the Olympics a few weeks ago? An example of a carbon part failing, right? Nope, that was a metal part (3d printed titanium if memory serves). So sudden, catastrophic failure isnāt just a thing of lightweight carbon parts. As I wrote under (1), if you push light weight to the limit, you often have to end up compromising robustness.
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I bought a carbon bike in 2004, raced it for 6 years, got it off the wall in 2018 and have it on the trainer most of the year due to local climate. It is the bike I"m currently crossing the country on. I had it painted when I started riding again and put a newer groupset on, but the frame is unchanged.
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I know in theory carbon is stronger but I wonder if the production process isnāt more susceptible to introducing flaws into the frame.
I donāt know anyone who has had an aluminium frame crack/fatigue. I know 3-4 whoāve had catastrophic failures to carbon frames - usually at the chainstays or seatstays. I havenāt had any issue with my own carbon frames but I have had a carbon Bontrager seatpost fail on me (I was a good bit overweight at the time, but I wasnāt that fat 
). Another friend has had carbon bars fail.
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I think Iām on a ratio of 2 aluminium to 2 Carbon over 15 +years.
On the aluminium front. A lad who worked in a lbs had his bottom bracket area of his aluminium bike crack and I had both chainstays crack on an alloy bike (actually Scandium) under my then massive 65kg load 
On the carbon front Iāve have seen two identical chain stay failures on Tarmacs (SL4ās) where I put it down to too much power by the riders 
Nothing in my limited experience suggests in terms of longevity one material is worse than another.
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I hear you on the sentimental aspect of this rentagreement. I have a hard time letting go of my bikes when I think about all the miles and great memories Iāve shared with friends on epic rides.
But, it doesnāt have to be this way. With a collection of 3-4 bikes you can re-purpose them for different riding conditions so that youāre still using them all.
I have a rule that if a bike goes about a 1 year without any use I can justify itās sale as bringing happiness to another riderā¦and then I try to find a buyer that will appreciate it.
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You take your risks either way I guess 
.
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Indeed. Material alone means very little. Design and implementation of said material is what matters. Each one has proās / conās and the only blanket statement that applies is that there is no such thing as a āblanket statementā when it comes to bike frame materials 
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I donāt know ā¦ I keep buying alu bikes; TREK Domane, CAAD10-12-13ā¦in the 2.000-$2250 range. I doubt if the 2.500-$3.000 difference to a 5,000 bike will give me equal fun. You can do lots of things with that saving. Sure if you donāt feel 5,000 in your pocket spend what you like but from a cost/effective point of view ā¦
I prefer traveling to some epic climbs regions with my alu bike rather than riding circles around the house with a 5,000+ carbon bike, make sure they donāt steal the thing, make sure I donāt crash, make sure I donāt set it against the wall in a not so gentle way. And for the occasions I overtake someone on a climb with my alu bike ā¦ priceless. I know ā¦ itās an old joke, but I keep enjoying myself with it. It even has neurotic proportions. When I pass someone I tend to tap on the frame, so they can hear it, itās alu made. Anyway ā¦ there is nothing wrong with spending your time online debating the carbon versus alu thread. Part of the buying process!
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I feel like the carbon difference is mostly weight-weenieism, and 99% of the feel of a bike comes from the contact points, bars, wheels, tyres and tyre pressure. That said, ~ a kilo of weight savings is a lot, especially with how heavy lots of even $$$$ bikes are now that disc brakes are becoming unavoidable.
Electronic groupsets are lovely, but based on what Iāve seen from using 105, Ultegra and Dura Ace, Iād be tempted to wait until 105 Di2 is out and get a bike with that - then potentially upgrade any of the wear components with significant weight differences over time.
That said, my last two bikes have been purchased 2nd hand, work great, and cost me about 1/5 of your budget.
I ride alu with a carbon seat post and a saddle with carbon rails. The seat post made a very noticeable difference when I first had it installed. I bet a full carbon frame is similar in its dampening effects. However, I abuse bikes and like to ride what I can easily afford to replace. My alu road bike is 16.6 lbs with carbon wheels and 17.3lb with my alu hoops so weight isnāt a huge driving factor
FYI if this were a metal frame the seatstays would probably also be broken
Most serious cyclists I know donāt treat their carbon bikes like that. It is a use item. That means you should care for it with regular maintenance and not do something stupid. But marks from regular use are fine.
However, I agree on the larger point: good alu frames are amazing, and I agree that a good aluminum frame with a good set of carbon wheels, a carbon seatpost and perhaps even carbon handle bars gives you most of the advantages of a high-end bike.
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