Have been playing around with my pedal location on downhills lately. As I look down at my bean pole crank arms,
it seemed that keeping them vertical caused a nice braking surface. So, lately I have been trying to keep them horizontal
on the down hills, and it seems I go a little faster. So, is this all in my head, or is there an optimum position
for the crank arms on long step downhills?
Dave
I think it makes sense to have the crank arm in an horizontal rather than vertical position since you would reduce the contact surface.
Fred.
I prefer to keep one leg pointed down with all my weight on that leg. Then I drop my head between the aerobars. This position offers less drag and more control than keeping cranks horizontal. With my position I can control the bike with the legs/core, better than your position and my frontal is much lower. If you try to stick your head between your aerobars with your cranks parallel, you won’t have that much control over the bike…by the way, hands are on top of aerobads with elbows tucked in like in the Obree Hour Record Position.
It is basically this position with the head lower on top of aerobars and hands on aeropads, with no pedalling.
Dev
I see knees together.
You may be right, just seems I have had a little faster speed horizontal. Probably do not have my head tucked enough.
Dave
Where are your elbows? On aerobars or where Obree has them? The only faster position is with nose over front wheel, which you can do on a road bike but not with aerobars.
Dev
Got to work on those elbows also.
Dave
I don’t know, but I put the knees together and the crank horizontal, slide my butt back off the saddle and put my chest and head as low as they can go.
If I recall correctly, I saw a pic of Walton tucked on his tribike and he was that way.
You just won’t have as much control over the bike with your pedals horizontal. I just find that nose between aerobars and weight on one pedal is more aero and less dangerous, than weight on your ass and head low…and just cause Walton does it, does not mean it is the fastest descending technique. I bet you I can out descend Walton on a technical descent :-). Age groupers may not have pro engines, but you don’t need a big engine to descend fast. Check out the TdF guys in the Alps…aside from very straight out descents, they always have one leg or the other down…there is a reason for this…control!!!
<< Check out the TdF guys in the Alps…aside from very straight out descents, they always have one leg or the other down…there is a reason for this…control!!! >>
Yes and no. The reason is cuz they are CORNERING, which is best done with the outside pedal fully weighted.
Has nothing to do with aero.
You have the disclaimer right there in the sentence - aside from very straight out descents - which of course for those they have their pedals horizontal, like they should.
<< I bet you I can out descend Walton on a technical descent :-). >>
I’ll take that bet. Real $, or that canuck funny money, your call.
If there are turns, I have the outside leg down.
Um, aren’t you neglecting the rather large issue of cornering clearance. Have you ever touched the inside pedal down on a hard corner that you tried to ride through rather than going outside leg down? I have. About three seconds later I was lying on the ground following a nasty crash. Cornering clearance is a massive issue…
TDF guys… downhillers… XC mountain bikers… all put one pedal down when cornering for one reason: to weight the outside pedal and lower the center of gravity and corner better (the same thing Moto GP guys are doing when they get off the inside of their bikes in corners). When descending in a relatively straight line they all have pedals horizontal and equally weighted (with the same foot forward that they would use on a skateboard or surfboard) for balance and control. It’s also more aerodynamic because lowering one leg exposes more surface area to the wind.
And if you’re hauling ass downhill your weight better not all be on your saddle regardless of where your legs are… your legs (both or outside one) should always be weighted enough to ever so slightly lift you off the saddle.
Also, as counter-intuitive as it sounds, your grip should be relatively loose (i.e. no death grips) on the bars and you should allow the bike to flow underneath you, if that makes sense.
.
Check out the TdF guys in the Alps…aside from very straight out descents, they always have one leg or the other down…there is a reason for this…control!!!
Aside from cornering technique which has been pointed out by many, 98% of the time you see the pros descend they are not attacking or time trialing. All out speed is not their goal. (Although sometimes it is, and after reading this thread I popped in the '03 tour DVD to watch Vino bomb into Gap… WOW!!! that was an exciting race!)
Edit: After watching more of that stage, I can tell you that almost all of the pros will descend with the cranks horizontal unless cornering or accelerating. One of the few exceptions seemed to be Lance who would only go horizontal when he was on the brakes or going off road.
Rappstar…which planet were you on :-)…of course the outside leg is down…and you switch sides as the road changes directions. I guess my main point is most downhills are sweeping one way or another. I actually have started using the Triatma position (still one leg down for better control)…in any event the position he shows appears to be symmetrical and on powercranks (I think)…tough to do on regular cranks. Plus if you are in a triathlon, there are actually people around, with big speed differentials, so one needs to have reasonable control.
OK, someone get Walton and we’ll start at the top of Alpe d’Huez or at the top of Ventoux and it is a deal. We’ll do two timed descents…one at a time. Anyone can follow someone down the mountain when the line is set just like in downhill skiing :-). On a straight out descent any big guy can just go in the aerobars and get reasonably fast…technical descents are another thing 
I prefer to use the concept of “pointing your belly botton” at the “next gate”. As soon as you do that, the rear wheel is tracking towards where you want to be next. A light countersteer with the hands and steering with your core works. Plus the lower you get, the more stable you are and the less you get blown around by cross winds.
Dev
Have been playing around with my pedal location on downhills lately. As I look down at my bean pole crank arms,
it seemed that keeping them vertical caused a nice braking surface. So, lately I have been trying to keep them horizontal
on the down hills, and it seems I go a little faster. So, is this all in my head, or is there an optimum position
for the crank arms on long step downhills?
Leg position definitely impacts your aerodynamic drag, which is why in wind tunnel tests the subject is either pedaling or is tested with their legs at various static positions (Chet Kyle’s preferred method). Thus, all else being equal you’ll be fastest down hills with your cranks horizontal.
Cool, nice to have something I see on the hills actually have some reason behind it.
Now, I only keep this position when I am going straight. When I go into turns, yep,
the outside leg drops!!
Dave
Cool, nice to have something I see on the hills actually have some reason behind it.
Now, I only keep this position when I am going straight. When I go into turns, yep,
the outside leg drops!!
Dave
Don’t you use PowerCranks? You should have both cranks in the 12 o’clock position when descending. No excuses.
At the risk of sounding like a smartass, how about pedaling down the hill. Unless you are completely spun out, you can still pedal.