I’m 80kg, ~340W FTP so not a small rider, have a lightweight 2004 aluminium frame that did tens of thousands of miles outdoors before being retired to indoor trainer duty in 2016. Have done maybe 1500 further hours of training with it indoors in very similar setup to the OP - direct drive trainer and rocker plate - including Zwift racing with maximal sprint efforts. No signs of anything like what the OP is seeing. I don’t think aluminium is a bad material for this use case, seems like a flaw with these welds (possible I guess that back in 2004 my frame was better made as it was still pretty high end back then)
You beat me to it! I edited that out because yeh - it is what it is.
Dang, that is a bit of a head scratcher. Looks like a good amount of insertion depth, but also a lot of seat tube sticking out. One other question- how tight is the cord holding your sweat catcher? Looks like that is way up there and would give a pretty good moment arm.
The weld does look suspicious right at what looks to be the crack origination. I would be surprised if specialized didn’t work with you on a replacement.
Could just be an unfortunate combination of all those factors. Best of luck with a replacement (or upgrade)!
I’m almost 100% sure its what I said above now.
In my mind, we are basically saying the same thing when you reference “concessions”. I don’t think they sat around and designed something to fail, but there are always trade offs between performance, quality, and cost. For that particular frame, it probably has an extremely low failure rate for 99.9% of situations where that bike is used (recreational riders putting out a small fraction of the power being discussed and for much less hours). The OP broke 2 of these frames in the same manner. I’m not much on coincidence with stuff like this, if it’s likely a design limitation or a common manufacturing defect that falls within acceptable standards for what they are paying the vendor. I’d almost guarantee they aren’t x-raying welds on a £1k bike.
My background is in manufacturing and supply chain, including a good bit of time working with Pharma and Aerospace where quality is a critical factor. Even in those industries, you still come up with a use case and accepted failure rate and then balance cost and quality. I assume it works similar in the bike industry, but I honestly don’t know. Do you really think that the frame on an entry level bike has the same investment in quality (design, process controls, etc.) as a bike that’s being ridden in the world tour? I wouldn’t think so, but don’t have the first hand knowledge to say for sure.
The same amount of engineering? Of course not. Quality controls? Very likely yes. I just outlined that above. All of our frames had to pass the same QC tests re: fatigue, failure, etc. And the lower end ones often lasted longer because they were heavier and more durable.
Just wanted to say the obvious @4ibanez , you didn’t do anything wrong. That’s a dodgy frame. It’s not because you let sweat drip on it. It’s not because your seatpost insertion depth was 99mm instead of 100mm. It’s not because your sweat guard applied too much compression across the weld.
It’s because that’s a dodgy frame. I don’t know if Spec will make it good but they should.
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It’s probably more along the lines that they know that so many frames in a thousand will fail and come back under warranty. Improving that number is probably way more expensive than just dealing with it. Maybe they see the same weld breaking and pass the info on up so maybe they can adjust the process if possible.
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What are you basing this opinion on?
This - its just cheap, hate to say it.
A $1k bike has a bottom industry sale price probably of around $590-$600 to a LBS (this is a EP estimate). That means what manufacturing/component cost is around $450? How much do you think they spend on the aluminum material and bonding process? Not much haha.
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You guys understand that there is a massive manufacturing knowledge base around aluminum frames, right? And that for the overwhelming majority of these frames, that existing knowledge is more than sufficient. Lower end frames are actually easier to manufacture because there is less engineering required and you rely on that existing knowledge base.
You don’t need to engineer every frame / product from the ground up every time.
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That’s not my argument - mine is they are racing to the bottom dollar and that’s affected across the board. The standards/quality just isn’t there on this level of product is all I am pointing out.
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See my previous comments re: testing on frames. Again, lower end frames tend to be more durable because there is not as much focus spent on pushing the edge in order to save weight, etc.
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Agree’ed but there is pushing the edge on saving money and having a better bottom line. Maybe specialized does not do that but the manufacturing center that is making them maybe brings in a different crew or uses different filler or thins the material out a little to save a few cents. Maybe they knock out so many frames at once that 1/100 frames fail because they don’t up voltage compensation for heat or slow the feed down.
The best way for the common person to find out why this material failed is to perform Vickers testing and assuming this is a 6061 seeing if it aligns with the proper hardness. You can test the weld and material and grind it out and measure the thickness of material.
Not something OP wants to do but that in itself could tell a lot.
I am not arguing with you, actually agreeing with you and talking openly.
10% failure rate on the frames may be cheaper then $0.50 more on material thickness or $0.75 on stress-relieving. We don’t really know.
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Agree with those saying that there doesn’t seem to be anything obvious wrong with how you’ve been using the bike, so I’m inclined to also think the frame design, material, or manufacturing isn’t good. I’d find a cheap carbon frame to replace it, because as you said, they are a bit kore fatigue resistant. If Specialized give you a new frame under warranty, I’d sell that and buy a carbon one.
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If it’s staying in the trainer, maybe a frame size up with a stem that’ll bring your bars to their current position, since road handling won’t be a factor. That, plus a more traditional frame design with a horizontal top tube and higher seat stays.
All that with the idea of providing more support and creating less leverage for this area that keeps breaking.
The longish seatpost combined with the front wheel riser is putting a lot of strain on that weld since the seat stays are lower. I don’t think it should break or that you’ve done anything wrong, it’s just a perfect storm. A different frame design (more traditional) should solve it.
If you do end up with a third frame of the same design, maybe a flex/softride seatpost would absorb some of the strain. Not suspension, just flexy.
I’ve had friends that had Specialized frames that broke. They got another frame no questions asked.
Just in case, I wouldn’t mention the trainer as some people think trainers can put undo strain on frames.
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That’s probably good advice.
But I’m just guessing the spesh rep is not going to have a hard time believing one of these frames broke. I mean, it’s probably not gonna be the first (or fifth) one that the rep has seen. (alloy Allez owners, head up, yo?)
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My warranty experience with S was good. My bike showed up with a rattle in a chainstay, and I expected a new chainstay…they sent a whole complete bike.
A guy I knew had a 10 year old Stumpy and cracked the frame. They sent him an up to date model frame.
I agree with most around here. It’s the bottom of the line frame. They did the math on manufacturing costs vs failure rate and just phones in the manufacturing. Very few of these frames will get mileage. Big S expects the Enduro (my bike) to get ridden hard, and mine has been abused WELL beyond normal use, because it was built to a higher standard. Just a business decision.
Anyone who thinks companies don’t do this kind of math need to look at the Ford Pinto.
I barely use a trainer, and at 150 pounds I’m not stressing my bikes the same way.