Aerodynamics / Aerodynamic Cost / Aero parts

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  • More suggestive shapes... (... from Rocket Science!)


    http://www.apogeerockets.com/education/downloads/Newsletter346.pdf

    It seem like you can lose ½ gram of drag by using a 1:6 ellipse shape: 0.07watts! :)

    or that any pointy shape basically works...

  • What speed range? Rocket nose cones have to deal with the trans-sonic region, not many cyclists do. The ellipse is easy to design, but not actually that great compared with other options of the same length. Haack is where it's at :-)

  • the paper is for model rocketry 39mph /tube size 17mm so pretty spot on. (but done by a 8 year old... (and her father))

  • Found an old RAE paper on solids of revolution in oblique airflows, which is relevant to our interests as both @umop & I favour extensions which are slightly angled at the pointy end, rather than straight or s-bend. Will try to find it again when I get home.

  • £?

    Dunno yet, need to tweak the drawing and then get the machinist to quote for various quantities. Unlikely to be under £40/pr unless loads of people want them.

  • Received my Chinese integra copy. It appears in this case, the cost of aerodynamics is aesthetics. Possibly a few teeth too. The alu clamp is shocking. Just going to test the length and height on a few rides before replacing it I think.


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  • What's wrong with it?

  • The clamping of the bars is pretty suspect. Had to sand the carbon half to get the bars in. Then the aluminium clamp didn't seem to fit well enough to hold the bars. The bolts are at the recommended 8N now. Which deformed the ALU. But at least the bars don't slip. After testing on the turbo its fine. But I ride a lot of bumpy descents. It was just a test anyway. I wanted to try a 110 stem, and a mates wants the ALU integra. Do for $35 I figured I'd try it. Getting a BLK-tec stem when its ready (end of month perhaps).

  • Really? You're gonna ride that POS?

    Leaving half your face on the road and breaking bones isn't much fun and my bike was in working order! :P

  • If the current weather conditions gave me hope of riding outdoors, more than a couple times before the end of the month. I'd have swapped it out. But I want to have at least one decent ride. I swapped out a 90mm. This is 8mm higher, and 18mm longer. Which actually feels good on the turbo. Just want to confirm that.

    Even if it went on perfectly. Its meant to be 50% lighter than the 3T Version at 15% of the price. So it was never a serious purchase.

  • If anyone would be able to lend me a disc rear/tri-spoke front for the Bespoked weekend that would be amaze - the wheels would be going on a show bike, so beyond being looked at they won't be used. You'll have my enduring gratitude, and a discount on a custom TT frame in return.

  • The video won - pulled the trigger on Evade.

  • @Dammit Might be able to lend you something, PM and Ill let you know what ive got

  • So tape on an air attack worked a treat. It stopped the rain blowing through today. There was no visor misting / head-boiling.

    I quite like it for TTs. I can drop my head right down and still see some road.

  • ^I'm almost tempted to try and DIY-aero my old road helmet that I'm well overdue to replace. I have spare window film at home that I could shrink on, but the main thing I'm concerned about is that I'm going to look like a right cunt.

  • And you won't with a pointy hat?

  • Just for a laugh I once stretched an old swim hat over my road helmet for a TT. It was years ago, but looked almost exactly like the modern slew of aero road helmets.

  • "Aero"* tri bar plugs will be available about the end of April. Usual deal, black anodised 6082T6, glue 'em in with Araldite Fusion, £15 each + p&p. I'm making enough for me and a few spare, but I can increase the quantity if anybody wants some.

    *actual aerodynamic performance not all that likely.

  • ... but designing for supersonic speed should be good for psy_ops purposes :)

  • 1.5crh is definitely in subsonic bullet design territory, .32S&W rather than 0.30-06

  • Found an old RAE paper on solids of revolution in oblique airflows, which is relevant to our interests as both @umop & I favour extensions which are slightly angled at the pointy end, rather than straight or s-bend. Will try to find it again when I get home.

    Did you find this? Sounds interesting.

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Aerodynamics / Aerodynamic Cost / Aero parts

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