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Adding "turbulators" to bike tubes?
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I just finished reading the Aerodynamics chapter in Mike Burrows' book Bicycle Design. He speaks about adding "turbulators" (airflow disruptors?) to bluff bodies, like bicycle tubing and aero-helmets, to create premature turbulent flow (at laminar type Reynolds numbers) and decrease its overall drag. He isn't clear on how large to make them (relatively speaking of course) nor does say where to put them other than a "6cm wide PVC insulating tape down the front of your fork balde." Does anyone know of some literature that explores this further? Or has anyone tried doing this on tubing? I know it's only theretical and probably doesn't have much application in the real world, but thinking about stuff like this keeps me off the streets and out of trouble. Wink

On a lighter note. Has anyone tried the "Mohican stripe" down the front of their legs? I want to try it just to see if I can get someone to believe that there's an aero advantage and "psych" them out. One thing I won't try is that Chia-Pet looking helmet. I can hear it now... "Ch-Ch-Ch-Chia!" as people pass me left and right. Shocked


E-Z

--It ain't a good idea to swim near MY bubbles! Tongue
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Re: Adding "turbulators" to bike tubes? [E-Z] [ In reply to ]
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There is plenty of research on trip wires and zigzag tape and stuff like that, a visit to a decent library or an internet search should be a good start.

We've done tests with all sorts of tricks like this, sometimes it works, usually it doesn't. Some good TT helmets use them successfully, on bike tubes and fork blades it's a lot tougher.

As for the zigzag tape on your legs, various federations are trying to ban those now. But this has little use, since technology has moved forward since and all sorts of 3D patterns are being woven into racing suits nowadays (see for example the Nike track running suits from Sydney, as well as TT suits and speed skating suits that Chet Kyle designed).


Gerard Vroomen
3T.bike
OPEN cycle
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Re: Adding "turbulators" to bike tubes? [gerard] [ In reply to ]
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Thanks Gerard. This post was fading fast and I didn't think someone was going to point me in the right direction. Now that you mentioned zigzag patern on helmets I remember seeing them on the helmets of Indycar drivers in the early to mid 90's. I don't think they used them anymore because the helmet shapes have changed. Those Nike suits are awesome. I saw a copy of their patent report. I wish I was that smart to design something so cool and funtional.

I get a kick out of seeing engineers and designeers such as yourself staying one step ahead of the rule makers.


E-Z

--It ain't a good idea to swim near MY bubbles! Tongue
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Re: Adding "turbulators" to bike tubes? [E-Z] [ In reply to ]
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Actually, the bike helmets that I know of don't use zigzag tape but a straight tripwire. Unfortunately I can't find a photo right now.


Gerard Vroomen
3T.bike
OPEN cycle
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Post deleted by Kraig Willett [ In reply to ]
Re: Adding "turbulators" to bike tubes? [Kraig Willett] [ In reply to ]
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Excelent article Kraig.


E-Z

--It ain't a good idea to swim near MY bubbles! Tongue
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Re: Adding "turbulators" to bike tubes? [E-Z] [ In reply to ]
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I always put my turbulators on the front fork and rear seat-stays. I prefered to attatch them with clothesline pins set parallel to the ground at 184-176 degrees from the contra-lateral distal edge of the actual turbulator...and my favorite turbulator was one of the face cards from a deck of red Bike Playing cards. These sound of my turbulators made me feel like I was REALLY going fast! I showed up at a time trial with them on my bike, but they said I couldn't run them in the race...some nonsense about safety...I just think they were afraid I'd have an unfair advantage! It would psyche someone out to hear me coming up from behind, wouldn't it?



Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)
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Re: Adding "turbulators" to bike tubes? [ktalon] [ In reply to ]
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Dude, you should have used the latest carbon fiber clothespins. They would have blended in nicely with your all-carbon machine (more stealthy, you know). Didn't you read the latest issue Weekly Laundry? HED is going to design a variable volume turbulator so that you can sneak up on people. And Renn is going to make one for us regular folk.

I'd pay to see people's reactions to you approaching to pass them with your "turbulators" rumbling away! All of us here are dying to see pics of your "Turbulator Talon" set-up posted here on the site. Don't disappoint us! It'll be a riot!

Wink


E-Z

--It ain't a good idea to swim near MY bubbles! Tongue
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Re: Adding "turbulators" to bike tubes? [Kraig Willett] [ In reply to ]
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Kraig

Thanks for nice evaluation report. Based upon the report date I guess the DuraAce wheels were the old WH-7700, correct ?

Any idea of how the changed spoking pattern in the new WH-7701 wheel will improve the durability and rear deflection ?
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