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Here are some pics of a TT frame that a Weight Weenie poster made on his own. Damned nice work he did. The thread that followed his progress is here. It's a worthy read.
 

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Whoa.

I usually open these "homemade bike" threads with a bit of skepticism. That is a pretty darn good effort. I'd like to see the finished product with wind tunnel data etc. to show the big guys it is possible to make a great bike at home.
 

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cydswipe said:
I usually open these "homemade bike" threads with a bit of skepticism. That is a pretty darn good effort. I'd like to see the finished product with wind tunnel data etc. to show the big guys it is possible to make a great bike at home.
Except, it's not UCI legal, we have no idea how aero it really is, and no idea how strong or stiff it is. I love the way he criticizes some manufacturer's bikes when he hasn't proven his design at all and doesn't have to work under the constraints they're subject to. If he wants to design an aero bike that doesn't have to meet UCI restrictions, he should be comparing his design against a Lotus or Superbike II, not UCi legal bikes. Unless he wants to share some wind tunnel and EFBe or similar data, all this is is a design exercise and a chance to get some experience in carbon fiber fabrication.
 

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asgelle said:
Except, it's not UCI legal, we have no idea how aero it really is, and no idea how strong or stiff it is. I love the way he criticizes some manufacturer's bikes when he hasn't proven his design at all and doesn't have to work under the constraints they're subject to. If he wants to design an aero bike that doesn't have to meet UCI restrictions, he should be comparing his design against a Lotus or Superbike II, not UCi legal bikes. Unless he wants to share some wind tunnel and EFBe or similar data, all this is is a design exercise and a chance to get some experience in carbon fiber fabrication.
What makes you think Samu's frame is illegal?
 

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IUbike said:
Lets be realistic, an hour and some pre preg fixes that. Samu has put forth an amazing effort and doesn't really need the likes of you bashing his work.

K
Good engineering consists of maximizing performance within a set of constraints. Samu chose to criticize bikes that are designed to work within the UCI restrictions and compares them to his which doesn't. (I can't believe how poorly those F1 cars perform as dragsters in the standing quarter mile, those engineers must be idiots) I'm sure the manufacturers he names could easily produce more aerodynamic frames if they didn't want to work within the limits of the UCI rules too. I know this because they would base their designs on something like the Lotus or Superbikes. So what has he accomplished? He's built a non-UCI compliant bike which falls far below the best in terms of aerodynamics (because no double diamond frame has ever come close to the open designs and even given a best case scenario, his would be only marginally better than todays best double diamond frames) and can't be used as an alternative to current double diamond designs because it is illegal for the events those frames were designed for.

As to bashing what he's done, I didn't invade his garage and post his work just for the purpose of criticising it. He posted his work, took some cheap shots at commercial manufacturers, and opened himself up for feedback and criticism.

Finally regarding the seatstays, If they're optimally designed, reducing the aspect ratio will have to reduce their strength, increase the drag, or both; either way he'd then have to make the same optimization decisions the commercial manufacturers do and for which he criticizes them.
 

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asgelle said:
Finally regarding the seatstays, If they're optimally designed, reducing the aspect ratio will have to reduce their strength, increase the drag, or both; either way he'd then have to make the same optimization decisions the commercial manufacturers do and for which he criticizes them.
From this GP poster's link: "Chain stay will be made Polar Power meter compatible since I have one new going to it. Just build mouting places directly in CS shapes."

That's pretty ill. Unless the battery dies, but don't you have to ship Polar stuff off to Finland to get them fixed anyway? If there's a way to take the unit out that I haven't seen, then I think he came up with a elegant solution for this particular bike which is as good as the SRM/Dura-Ace crank (the patented "fil up hollow stuff" or "baked ziti" approach.
 
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