I am having a set of carbon tri bars custom made (see http://www.mdt-products.com/products/239-zerobars/zero.htm) and need to tell them where to place the elbow cups as they are not adjustable. I am told by the manufacturer that my current elbow position is probably too narrow as the new way of thinking is your elbows should be wider apart.
I am told ideally the elbows should be placed where they naturally ‘drop’, sit under the shoulders and just within your thighs with the arms angling inwards and the hands coming to meet at the bar ends. With this ‘arrow’ arm position the airflow is directed around the moving thighs, adds nothing to overall frontal area, and the chest is not restricted.
My current setup, on Syntace, cup center to cup center is 25cm
Naturally my elbows ‘drop’ on a table, elbow center to center, at 33cm
My shoulders on the bike, outer edge to outer edge, are 38cm
My thighs on the bike, outer edge to outer edge, are 42cm
Anybody suggest where my new elbow pads should sit, center to center?
i’m not an expert. but john cobbs is. of course, you’d be much better served by an actual response from him, but lacking that (so far), i can refer to you to an article about a bike-fitting he did.
an excerpt: Once again, I had read that more narrow the elbows, the more aero the position. So I worked something fierce on my shoulder flexibility and managed to get my pads nearly side by side. Have a look at my front view photo and you will see that my elbows are relatively wide (for me at least). Cobb Lesson #5 — The elbows need only protect the legs
gordo and john - i’m sorry if this has been a copyright infringement or if i’m stepping on your toes by referring to your article/advice. and if i’m wrong, PLEASE correct me.
Well, I have yet to find an aerodynamic rule that is universal (maybe withthe exception of “riding with a flapping cotton T-shirt is not very aero”) but in general wide elbows are not very aero. It would be tough to do the tweaking to find the best position without using a tunnel, but as long as the elbows ae not wider than your knees you should be in the ballpark. Of course, a very big imporvement in aerodynamics can be made by keeping your knees in, which in turn requires you to keep your elbows in. Top riders do this automatically, a few weeks ago when we were positioning Carlos Sastre in the tunnel his elbow pads were about 2-4 inches closer in than yours and within that range we found the best position for him (which BTW was not the narrowest position). But anywhere in that range was much better than his original position which had the elbows outside of his knees. and that seems to be true in most cases.
i agree, some people ride with there arm touching,in my mind that catchs a lot of air that has to spill around the arms,i just moved my elbows out ,i am not where i used to be but might go wider
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To me, it seems that the arms should cover the knees. Like gerard said, if the knees are closer, the arms should move closer, if the knees are out, the arms should move out. While frontal area isn’t the whole story, hiding as much as possible from the wind is a good place to start.
I don’t really see the arms “deflecting” any air, as a fairing would since a good portion of air will flow into the chest, the arms can’t do anything about that, it’s just a matter of filling in dead air with the knees- namely reducing the frontal area, and maybe the pressure drag by providing the air with a more aerodynamic shape to follow than a circular arm (which has significant pressure drag).
But then again, intuition has led many men astray, so who knows unless we have the tools to measure such things.
I just got fit by Paul Levine and he has my elbows as far out as they can without being outside of my thighs. My understanding is if you go to narrow, you may be less stable and balanced while doing nothing for you aerodynamically because the wind is still hitting your thighs.
With my new set-up, I am more confident descending and definetely feel more stable. FWIW.
It doesn’t matter to me where the “most aero” elbow postion is found. I lose the feeling in my hands after 30-45 minutes…especially in the left one, if my elbows are too close. NOW, I finally have an excuse to be more comfortable and put my elbows wider…don’t know if I’m faster, slower, or the same, but, I can certainly ride with less discomfort this way!
Man, where do all these people with no shoulders come from? That guy is about as wide as a medium-sized housecat. I guess that’s another reason I’m not a world-champion bicyclist, my shoulders are certainly a lot wider than my hips!