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Designing a carbon bike and an aluminum bike with the heavily manipulated frame shapes of today are effectively 2 different processes altogether. Aluminum is an Isotropic material and carbon is an Anisotropic material. What thats means is the material properties of aluminum are the same in every direction and with carbon is very different in each direction and the lay up orientation drives the material properties. With manufacturing a carbon frame it is just a mold with a predetermined prepreg layup pattern that’s cured in an autoclave. With aluminum you have to form the tubing to variable shapes and thicknesses, usually with hydroforming or air forming and then the frame pieces are tig welded together in a jig. The 2 processes share almost no common technology even if the end product looks the same. With carbon the more times they can reuse the mold the cheaper the part will be. With aluminum the cost is somewhat more broken down to each build allowing more size options especially if you can use the same tubing dies and then cut the tubes down. Flatland Crusoe fucked around with this message at 17:55 on Aug 3, 2020 |
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Aug 3, 2020 17:29
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| # ¿ May 12, 2024 13:34 |
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kimbo305 posted:As long as carbon frames are laid up by hand on molds, their human cost is gonna be a lot higher than alu. Maybe I'm underestimately how long it takes to finish welding up an alu frame in a jig. Not to say that their margin couldn't be better than aluminum, but you can't send as many cf frames through N molds as fast as alu frames through N jigs. I’m pretty sure the direct labor cost with AL is going to be higher based on the time and skill required to tig weld aluminum. With carbon the layup is a semiskilled task. The material costs with preprep carbon is going to be higher than Aluminum by quite a bit. And so are the fixed costs of setting up carbon fiber manufacturing.
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Aug 3, 2020 18:02
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Spime Wrangler posted:On yet another front i hear trek recently started dropping component tiers to squeeze carbon rims into all their carbon-frame builds without changing the price point. No man it’s an XT group, it’s got an XT front derailleur.....never mind the non series crank and brakes and Deore shifters, rear derailleur, cassette and chain.....
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Aug 3, 2020 18:56
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meowmeowmeowmeow posted:Does anyone have any sources for these claims? I work in a non-bike part of sporting goods and Asian manufacturing and uhhhh a lot of it contradicts what I've seen. My cost and labor assumptions are based on cost assumptions I have from US based manufacturing experience outside of cycling. I also realize until you’ve worked in the niche manufacturing sectors that the economics can be pretty mind blowing about how much things do or don’t cost to make. I never really considered labor to be a huge cost difference in the AL vs Carbon breakdown. Rather I always thought a lot of it is tied up in the raw material cost of carbon fiber an the intellectual property in the manufacturing processes. If you read enough velonews/bikeradar/bike rumor factory tours you will see noone shows the steps between the initial mold layup and the unfinished frame ready for sanding and paint. There is a lot of art in composite manufacturing with all the inflatable core bladders and final parts joining that no one shows the media. Getting good bonding and uniform resin ratios are pretty huge for composites and they vary greatly by process. I would guess that if you look at the cost of the raw 7000 series aluminum in a frame versus the prepreg carbon you are talking 5-10 times the material cost for the carbon.
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Aug 3, 2020 20:26
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kimbo305 posted:At current bike sales volumes, does either tech run the risk of wearing out a die or mold in the run of a bike? I’m not aware of any reason the molds would wear out especially given low volume of production. The cure temps aren’t that high, like 250-400f as far as I’m aware. They have always been unfinished aluminum whenever I’ve seen pictures. It’s not like a closed die forging mold that wears out daily. Lay ups should be pretty fast with standard work charts. If One person does all the 56cm frame bottom brackets for a week straight with laser cut pieces pre-sorted they will be very fast, like done in minutes fast.
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Aug 3, 2020 20:34
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| # ¿ May 12, 2024 13:34 |
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kimbo305 posted:I'm not aware of any bike frame manufacture being substantially mechanized. I thought every weld joining tubes was done by a human. I would guess your cheaper bikes produced in Walmart quantities are probably pretty automated and likely robotically welded. The combination of thicker wall tubes, almost no sizing variation and huge total production numbers would make it the most worth while business case. The opposite side of that is probably something like a specialized chisel or cannondale caad13 with low production quantities and very thin wall tube with lots of manipulation. Whether you automate a manufacturing process or not is the simple math of the capex payback to the labor rates and production volume. I know what an integrated robot cell costs for a given process and then I know my total cost for a line worker. If I can offset the labor cost in a predetermined period (often 2 years or less) we automate the job.
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Aug 3, 2020 21:35
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