Seems to be pretty solidified on Zipp wheels, helmets, water bottles so why not on frames yet? Is it structural or do bike companies think it’s just a bunch of crap?
They don’t rotate. Which is the main reason for their application on wheels.
Yeah, but I don’t think that necessarily means that it reduces the benefit. Didn’t you watch the mythbusters episode with the dimpled car?
Yeah, but I don’t think that necessarily means that it reduces the benefit. Didn’t you watch the mythbusters episode with the dimpled car?
Nope, I don’t have cable.
Yeah, but I don’t think that necessarily means that it reduces the benefit. Didn’t you watch the mythbusters episode with the dimpled car?
bikes don’t go that fast.
the top half of a wheel does =)
http://dsc.discovery.com/videos/mythbusters-dimpled-car-minimyth.html
Considering they didn’t control AT ALL for wind effect that test is basically worthless. I’m assuming they didn’t do their clay in 15 minutes even if it only took a few hours a directional change from north to south or whatever would have had a dramatic effect on fuel consumption.
then why on the helmets? There are a lot of elements that make their way onto frames that won’t have massive improvements on the overall speed of the bike, why not these? Any benefit could be worth it, right?
then why on the helmets? There are a lot of elements that make their way onto frames that won’t have massive improvements on the overall speed of the bike, why not these? Any benefit could be worth it, right?
Because lots of companies like to say their shit is awesome and do something different just to show you how awesome it is. Well how awesome their bs is at least.
http://dsc.discovery.com/videos/mythbusters-dimpled-car-minimyth.html
Considering they didn’t control AT ALL for wind effect that test is basically worthless. I’m assuming they didn’t do their clay in 15 minutes even if it only took a few hours a directional change from north to south or whatever would have had a dramatic effect on fuel consumption.
That test is worth the same thing as virtually every other ‘test’ performed on Mythbusters. Even my 12-year old easily figures out the fallacies in their procedures.
We absolutely laughed our asses off when they had the girl runner on the show that was going to ‘walk on water’ with the silly platforms they put on her feet.
Greg
then why on the helmets? There are a lot of elements that make their way onto frames that won’t have massive improvements on the overall speed of the bike, why not these? Any benefit could be worth it, right?
could be total horsecrap
hell so could the dimples on the wheels.
I’ve still not seen that verified effective in an independent test
What about dimpled thighs?
The more dimples the better
The more dimples the better
Thanks nealhe…
Laying dimpled carbon for a frame would be a bitch. I would assume you’d need to make the frames heavier, because in order to maintain the structural integrity, you’d be adding extra layers of carbon on the outside to do the dimples. Not to mention, I’m sure that the UCI would ban that pretty quickly, since I know they’re big fans of innovation.
There is only one way to settle this. Wind tunnel and in field power data. I actually was trying to think of a way I could test it my self last year but I could not figure out how to do it. The biggest problem being not having a round tubed bike to modify.
Myth busters rocks!! For all the haters those guys are out there doing stuff(not just sitting around talking about it) and trying to figure out the answers to many difficult questions in the most efficient means possible and doing a damn good job of it. Their level of technical ability, ingenuity, and creativity is incredible.
Ridley have textured paint on the Dean. Gaffer tape gives the same effect 
Cheers
Laying dimpled carbon for a frame would be a bitch. I would assume you’d need to make the frames heavier, because in order to maintain the structural integrity, you’d be adding extra layers of carbon on the outside to do the dimples.
How is it done for rims then?
I think the speed of the airflow over the surface and the angle at which it’s hitting it has a lot to do with how successful the dimples are.
For a wheel, the top surface is by all means travelling faster and therefore the air is travelling faster over it. As for the helmet, this is a large blob basically passing though the air. As it does so the air hitting it must pass around it and therefore has to accelerate faster than the adjacent ‘normal’ air. So overall, the air passing over the thickest part of a helmet would actually be travelling relatively quickly.
The dimples will effectively re-energise the layer of air passing over the surface and improve the negative drag effects. There will be an optimum speed at which these dimples are needed to do this re-energising. On a frame, the airflow is simply too slow as the frame is nowhere near as thick as a helmet (accelerating the airflow) nor travelling at the same speed as the top of the wheel.
Although I can’t quite work out how, I’m sure yaw angles come into it all too!
Dimples are for when you have your form changing its orientation relative to the airflow over the form. When you dont, there are more efficient trips for the air, such as the ‘chevrons’ which you can buy to stick on as an aftermarket on sailplanes and small aircraft. Wheels spin and thus change their orientation of the trips relative to the airflow over the wheel; whereas a frame (or a helmet) will not, thus a dimples surface would not be the ideal addition if your goal was function. There is actually a large body of literature on the subject if you look to small aircraft and sailplanes (neither of which I do); whose operation speeds are in lines with providing useful information to bikers. From what I have read, if you go to the information on jets and higher speed aircraft, the usefulness of that information decreases for our purposes.
On a side note, a lot of that stuff is for marketing so that they can sell you new stuff. It may offer some improvement, but it is mostly to get you to buy their stuff. If I were them, I would try to get you to buy my stuff as well.
Stephen J